2000 Ford Mustang No engine light!

Tiny
HASTEWIN
  • MEMBER
  • 2000 FORD MUSTANG
  • 195,000 MILES
I have an intermittent stumble. I have idle throttle snap hesitation. Vehicle has a manual transmission and my RPMs are very slow to drop. I have replaced the spark plugs and wires, fuel filter, crank position sensor, TPS, IAC, Coolant Temperature Sensor, EGR valve, and cleaned MAF sensor with approved cleaner. I can verify that at one point the MAF sensor was contaminated with K&N air filter oil. I cleaned that off. And the warm idle voltage output of the Mass Airflow Sensor was.77 volts at idle. Is that good or bad? I can't find that information anywhere. Also my Vacuum pressure at the intake manifold was a very steady 22 in! And not ONCE during this entire episode have I been blessed with the Service Engine Soon light! I have also verified that there are not any dormant codes on my OBD2 computer.
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Friday, August 23rd, 2013 AT 2:03 PM

27 Replies

Tiny
MHPAUTOS
  • EXPERT
Bit hard to tell with out actually hearing a problem like this, but I would be checking air flow meter, and TPI sensor, coolant temp sensor also ensure that the plug gaps are correct.
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Saturday, August 24th, 2013 AT 6:37 AM
Tiny
HASTEWIN
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At idle I am sitting at 700-775, varying wildly. And while at idle and I tap the gas, the engine jerks briefly before accelerating, in which I would identify this as a hesitation. And there is an occasional backfire through the intake, and the sound produced is at the air filter. It is a brief echoing "thump" sound. And the sound is always triggered by turning the A/C on. Also, my 2000 mustang is a V6 3.8 liter with a manual transmission. And my RPM's are terribly slow to drop, which makes for major drivability issues including having to wait until the engine slows down in order to shift up to the next gear. I verified that my spark plug gaps are at an exact.54 inches. They are new and double platinum spark plugs granted I needed those for my waste spark ignition system. Today I changed the Mass Airflow Sensor with absolutely no effect. I also unplugged my battery for 20 minutes afterwards. I also already replaced the Coolant Temperature Sensor previously. I also already replaced the ignition coil pack along with plugs and wires previously. And I replaced the Throttle Position Sensor. Also the Idle Air Control Valve is brand new. And my EGR Valve is brand new. I have never got a check engine light during all of this. And yes I know the light is not burnt out. It does come on with the ignition switch. Also my vacuum pressure is a steady 22 in. Please help! Thank you!
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Saturday, August 24th, 2013 AT 11:15 AM
Tiny
MHPAUTOS
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The clue here is the backfire through the intake, this is often caused by ignition voltage leaking, when it is dark get the car into a shed with no lights on, open the bonnet with the engine running and crack the throttle, if there is any shorting in the ignition you will see it in the dark.
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Monday, August 26th, 2013 AT 4:32 AM
Tiny
HASTEWIN
  • MEMBER
You were definitely right about the voltage leaking! Upon inspecting the coil positive 12v wire I noticed there was a half inch bare spot on the insulation of the wire. This was due to me installing a tachometer adapter (by Autometer) in order to get an aftermarket tachometer signal. I don't know how the wire got bare. I do know that my car is dropping RPM's faster and more like it should. I am having trouble identifying "normal" engine behavior at this point. How fast should my RPM's drop with my motor and ignition system? I do know it has never had a rapid RPM drop. I heard you can modify the IAC gasket to make it slightly larger and a bit restrictive in order to get a faster RPM drop. Would you frown at this? Also that intake backfire is definitely a lot less apparent. It has been even more brief and rare. Now my question is, will my car's computer adapt to this fault being repaired? And did my car's computer adjust the air/fuel ratio according to the fault while it was present? In other words how did this fault impact the function of the car's computer? I hope this eliminates this intake backfire all together. I believe that it is fading away but slowly, I am hoping that my computer is still adjusting to things being right now. As far as I know there are no other faults in wiring or hoses to cause problems. So I am assuming that my computer is adjusting to things being proper. I sure hope that is the answer. I do know that the engine is running a lot stronger. Thank you very much in pointing me in the right direction!
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Tuesday, August 27th, 2013 AT 5:57 PM
Tiny
MHPAUTOS
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ECU's can be strange beasts, with in the program there is a set of parameters to which it will "self adjust" to maintain optimum engine performance, once any of these parameters goes out of range, that is when problems begin. More modern systems use a fuzzy logic, that is they can go out of parameter and sill stay within normal operating conditions, if it wanders out more than 5 times in a row, it will then set a code, engine speed to idle is not something that you normally worry about as long as it is a constant and not stepping down there should be no problem. If you alter any system, say fit a new coil that is working far more efficient than the one replaced the ECU with adjust in millisecond's they ecu is re adjusting all tune setting all the time faster than you can think about it, so what you need to consider is make sure that all wiring is secure no bare or loose connections, no vacuum leaks, clean fuel, good fuel pressure, clean air filter, and no codes, the inlet back fire will not be tuned out by the ecu it is an introduced problem that need to be eliminated.
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Wednesday, August 28th, 2013 AT 5:08 AM
Tiny
HASTEWIN
  • MEMBER
Okay I understood what you are saying. So, the ECU can only compensate for certain things and it does so very rapidly. I do know that my ECU has a learning process for air/fuel ratio levels for every operating condition. Nevertheless I understand that the ECU is not capable of curing an inlet backfire. However I have a small hunch that my DPFE sensor is factory and it is made out of "pop" metal. I have heard that this sensor for my EGR system, has earned a reputation of gradually failing in its sensitivity to exhaust gas pressures due to moisture getting between the metal and contaminating the circuit board. I do know that this sensor possesses a 5volt reference signal from the computer (and a ground) and provides a feedback signal with a voltage range between.55 volt to 4.66 volt (only on the pop metal design like mine). I obtained a reading of 1.26 volts at idle with no noticeable change in voltage while revving. Maybe the vehicle wasn't utilizing the EGR system during my test? I believe the vehicle was at operating temperature during my test. Also, the replacement part for this sensor is a redesigned plastic component with a different voltage range! This is what is puzzling me, the replacement part has a voltage range of 1.0 volt to 4.95 volts. I believe that this sensor could be weak at this point. I do know the part has not been recalled but I do know that it has been redesigned entirely. Also I do know that if the sensor is working but lying, the computer will just believe it and mess things up. I believe this matches my symptoms as well. Well, maybe. At a cold engine start (while in open loop) the vehicle seems to perform better to the point where I do not recall an inlet backfire during this time. About 5 miles down the road my vehicle enters closed loop at this point and this is where things get a little unpredictable. What happens is, it doesn't idle properly. When traveling approx. 40 mph the RPM was already at a low 720 and failing to provide the vacuum assist the car needs while mobile. This only happens once in a while and it seems to be while entering closed loop. After in closed loop a while the vehicle idles properly while coasting by being within the 800-1000 RPM range. It seems like a closed loop "shock and confusion" situation that the ECU compensates for. Also the inlet backfire has never occurred above 800 RPM. It only occurs When my RPM sneaks just below 700 to about 690 and you can then observe its recovery to normal. Braking to a complete stop while turning will trigger the intake backfire and RPM drop, sometimes that is. My only guess is that my DPFE sensor is lying to the computer and its believing it. Just to mention I have installed an aftermarket coil pack that claims to provide 10 percent hotter spark than factory. That is something the computer is able to adapt to so I can't see that being the problem. Thank you!
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Wednesday, August 28th, 2013 AT 10:05 PM
Tiny
MHPAUTOS
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Problems like this are sent to test us to the max, you are correct when you say that a sensor can lie to the ECU and the ecu accepts this a correct, the fail safe with this (to a point) is that the ecu will gather information from all sensors and combine the reading to make adjustment, it may over ride to a point, if one sensor is reading incorrect (but in still in range ) as the other sensors combined will give enough information for the ECU to adjust to best performance available, well this is the theory. But in the real world this is not always the case. I am leaning towards a problem with the TPI, but as I am working blind, I an having a hard time visualising this, you are probably on the right track with the DPFE but I feel that it is going to be a case of trying a new sensor and seeing what happens.
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Thursday, August 29th, 2013 AT 2:59 AM
Tiny
HASTEWIN
  • MEMBER
All right well believe it or not I am back. Sorry it has taken me forever to reply to this post. But, however I have been digging deeper and deeper in my research. I obtained an OBD2 scan tool that can read Mode 06 data. Of course since I have no check engine light, this will be the only way to identify the source of the hidden problem I have. So I had to do some digging and found out that my, "delta pressure for downstream hose test and threshold" FAILED. Which is TID $41 CID $12 on the chart from my scan tool. Also, my "initial tank vacuum limit minimum" FAILED. Which is TID $21 CID $00 on the chart. I do know that I have a Fuel Tank Pressure Sensor and it is above the gas tank. But I wonder if that sensor is actually okay and something else is preventing vacuum from being held in the gas tank. Maybe my gas cap is too old to seal? I do know it is 14 years old and says TURN TILL CLICK, ENGINE LIGHT MAY COME ON. That is my small hunch. As for the DPFE hoses, I am going to be removing the EGR 1/2 inch dia. Exhaust pipe and cleaning the inside and see if debris is blocking my downstream hose, since I am assuming that this is what the scan tool is telling me. Please help, also hopefully me posting my scan tool chart will give you all the answers. Here it is. Thank you, sorry for the FORMAT SQUISH.
Service $06 - On-Board Monitoring

Date: 9/21/2013 3:44:43 AM

Component Description Value Minimum Maximum Units Result
Component Id $11 TID $01 - Manufacturer Defined 839 512 N/A Pass
Component Id $01 TID $03 - Manufacturer Defined 461 0 N/A Pass
Component Id $02 TID $03 - Manufacturer Defined 461 0 N/A Pass
Component Id $21 TID $10 - Manufacturer Defined 23 N/A 54 Pass
Component Id $11 TID $10 - Manufacturer Defined 24 N/A 54 Pass
Component Id $00 TID $21 - Manufacturer Defined 61015 61184 N/A Fail
Component Id $00 TID $21 - Manufacturer Defined 61015 N/A 61440 Pass
Component Id $00 TID $22 - Manufacturer Defined 32768 N/A 57344 Pass
Component Id $00 TID $25 - Manufacturer Defined 32768 1536 N/A Pass
Component Id $11 TID $41 - Manufacturer Defined 65434 64274 N/A Pass
Component Id $12 TID $41 - Manufacturer Defined 65434 N/A 883 Fail
Component Id $20 TID $45 - Manufacturer Defined 13056 N/A 20800 Pass
Component Id $30 TID $4A - Manufacturer Defined 2303 768 N/A Pass
Component Id $30 TID $4B - Manufacturer Defined 14180 N/A 26214 Pass
Component Id $00 TID $50 - Manufacturer Defined 0 N/A 2726 Pass
Component Id $01 TID $53 - Manufacturer Defined 0 N/A 21504 Pass
Component Id $02 TID $53 - Manufacturer Defined 0 N/A 21504 Pass
Component Id $00 TID $54 - Manufacturer Defined 218 N/A 21504 Pass
Component Id $00 TID $55 - Manufacturer Defined 21 N/A 2097 Pass
Component Id $00 TID $56 - Manufacturer Defined 1893 N/A 3000 Pass
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Saturday, September 21st, 2013 AT 2:11 AM
Tiny
MHPAUTOS
  • EXPERT
Often the fuel cap is the culprit. It the easy and first place to start, the rest of the EVAP system can get a bit nightmarish, but if you start at the cap and using a good schematic of the system, you should be able to nut it through, check carbon canister as well and all evap vacuum lines and valves carefully.
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Saturday, September 21st, 2013 AT 4:02 AM
Tiny
HASTEWIN
  • MEMBER
Hello, I replaced the fuel cap and replaced the EVAP test hose inside the passenger side fender well since it was kinked and degraded. I know that hose just lead to a dead end but I was afraid it was leaking so I replaced it. And I haven't been able to drive on the highway in order to activate the EVAP monitor test within the ECU, so I don't know how helpful those things were yet. However, I have noticed a "gurgling" sound after shutting off the car and it is sound only heard with the hood open. And I know for a fact it is coming from the cooling system. Which indicated that there is air within my cooling system. Upon my recent replacement of radiator hoses switched to silicone I failed to even acknowledge the vent plug or bleeder valve sitting above my water pump. Apparently the proper procedure for putting coolant in my car is to remove the vent plug BEFORE filling the radiator. Then, you put coolant in the vent plug's hole until full. Then reinstall the plug and run the motor with the radiator cap off and fill radiator as necessary. And to NEVER operate engine with vent plug removed, which I never did that since I didn't know about the vent plug. So, today I removed the vent plug and put coolant in the vent plug's hole until I couldn't anymore. If fit about 6 or 7 ounces of coolant in this portion of the system. I did recognize that the tee that this vent plug is on has a pipe that goes right beside the coolant temperature sensor on the inside of the motor. So, I can see how they would affect each other. My question is, how will I be certain I have all of the air out, even if the vehicle starts acting right? Should I repeat filling the vent plug hole with the engine off, that is if I can fit anything in there? Also on my scan tool I noticed that my temp goes around 196 degrees after like 15 minutes of driving, which I am a little uncomfortable with that, is that due to the air in the system? I also know that the ECU only allows 7 minutes for the temp to be at 140 degrees or it will set a DTC for a bad engine coolant temp sensor. I know the engine coolant temperature sensor is fine because it is brand new. I see degrees on my scan tool because the ECU calculates it in degrees. With that said I do wish I had a reference in numbers in order to know rather I have resolved this problem. What would you call a normal coolant operating temperature on a 2000 mustang v6 3.8 liter? Thank you for your expertise!
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Wednesday, September 25th, 2013 AT 6:23 PM
Tiny
MHPAUTOS
  • EXPERT
It has become popular to install high pressure radiator caps in an attempt to lower cooling system temps. While some makes and models come from the factory with and are designed for high pressure caps, raising your radiator cap's pressure above factory specs increases your cooling system's maximum operating pressure above design parameters. While raising your cooling system's maximum operating pressure does raise your cooling system's boiling point and therefore helps to avoid boil-over, it does not lower your operating temperature prior to boil-over, and simply allows your engine to continue to operate at temperatures higher than it is engineered for. Water boils at 212 degrees, and for each pound you raise the system pressure it raises the boiling point 3 degrees - Example: The 1.1 bar (16 pound) cap will have a boiling point of 260 degrees. Operating your engine at higher than acceptable temperatures can destroy your engine. We wish to point out some considerations that should be taken into account before an individual chooses this approach.

There are several possible reasons that you might be experiencing higher than normal cooling system temperatures:

An engine malfunction or cooling system problem - increasing your cooling system pressure will not correct this problem and will quite possibly add to the problem. We recommend correcting the problem instead of using a higher pressure cap.
Engine or body modifications have altered the performance of the cooling system or air flow through the radiator. Again, we recommend correcting the problem instead of using a higher pressure cap.
Engine modifications have increased the HP of the engine - creating more HP means creating more heat. We recommend increasing the heat dissipation capabilities of your cooling system to match the increase in heat generation. The best way to do this is install an All-Aluminum High Performance radiator, increasing the radiator cap pressure will not help dissipate additional heat.
Your car is being driven in a harsh (high heat) environment or is being driven hard for extended periods of time. Again, the best way to solve this problem is install a High Performance radiator, increasing the radiator cap pressure will not help dissipate heat.

Raising your cars cooling system's operating pressure increases the stress on all the other components of your cooling system. Before increasing your cooling system pressure by replacing your radiator cap with a higher rated radiator cap, check to make sure your entire cooling system is in excellent condition and all of the components are capable of handling these higher pressures. These may components include, but are not limited to:

The radiator (all of the All-Aluminium radiators that we sell are rated to handle these higher pressures)
Radiator hoses
Heater hoses
The heater core
The water pump
Freeze plugs
All gaskets that come in contact with the cooling system

Increasing your cooling system pressure by installing a radiator cap that has a pressure rating higher than factory specs increases stress on the entire system. Although some race cars use high pressure caps, their cooling systems are built to handle these higher pressures (All-Aluminium brazed and welded radiators, steel braided hoses, no heater core, high performance water pump, high performance gaskets, etc). I recommend that you only use a cap with the pressure rating that your car was designed for.
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Friday, September 27th, 2013 AT 4:49 PM
Tiny
HASTEWIN
  • MEMBER
Okay well now I am waiting for my DPFE hoses to come in. I inspected them before and they appeared to be free of imperfections, but I was wrong. I noticed that they are the original hoses and that the ends of them are stuck expanded where they hook onto the nipples of the exhaust and the sensor. And apparently this wearing effect of the hoses has allowed the computer to detect that one of the hoses are not holding the proper amount of pressure.
I am also going to replace my coolant with the proper filling procedure this time. But that is just proper maintenance, as for this repair of this vehicle I am lost after replacing these DPFE hoses. I can't imagine what else it could be after these hoses are replaced. Apparently it is not my EVAP system because I finally got that monitor to be ready. Now all of my OBD2 monitors check out 100 percent. I will just have to wait and see. But the only thing that my ECU is telling me is that the DPFE hoses aren't up to par.
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Friday, October 4th, 2013 AT 3:54 PM
Tiny
HASTEWIN
  • MEMBER
Also I was adding coolant to my radiator while at operating temperature, well while I was waiting, I had discovered that the radiator cap itself was in fact, leaking. So, I read on the top of the cap that it was a 16 p.S.I radiator cap. So, of course I replaced that for like 10 bucks, and now I can tell that the cooling system is holding pressure in the upper radiator hose with the vehicle off, where as before it was not. So, I am also noticing that the plastic coolant reservoir LEVEL has not been changing accordingly to coolant expansion. So, I am assuming that there is still air pockets in my cooling system due to the improper filling. Either way I am just gonna start over and fill it the right way on that. Thank you!
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Friday, October 4th, 2013 AT 4:07 PM
Tiny
MHPAUTOS
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If you can park the car slightly nose up this will help air escape, and if you use a filler adaptor, this keeps a head of coolant above the filler this will also aide in bleeding.
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Friday, October 4th, 2013 AT 4:24 PM
Tiny
HASTEWIN
  • MEMBER
Hello I have a major update to what I have been through with this car. Since the coolant concerns, I had discovered that the motor mounts were completely torn through. So I did replace those myself, which was really easy. That eliminated a lot of various minor issues for sure. Also I had discovered that my tach signal adapter was hooked up in reverse polarity due to a misrepresentation in the diagram for it. And that thing was causing the loss of power and a weird running engine. After that, I eliminated it from the ignition system and returned to factory. Problem fixed. After that, I was getting more power back, but I was now having an erratic idle. It was still hanging on the RPM's and idling way too low while in neutral. Well, the problem there was the brand new IAC valve that I had purchased from O'Reilly auto parts. The idle gave suspicion to the Idle Air Control valve. I then put my 13 year old original Ford IAC back on the vehicle in order to return O'Reilly's part and BOOM, magically my car is running like it should. Now the RPM's drop rapidly when I let off the gas, like it should, you can now even hear a burble sound in between gears from rapid RPM drop. And now when I brake and turn at the same time my car doesn't want to die from the strain of the power steering load. Now it idles at 1000 RPM when moving, and 750 while stopped, just like it should. I was always scratching my head as to why the ECU was failing to compensate for engine load. I also found out that my car doesn't even have a Power Steering Pressure Switch, since I was researching that to be a possible cause. What puzzles me now is that factory IAC valve that is on there now; did not ever close its plunger completely. I assume this is normal since my car is now functioning properly. Granted any new IAC you see does have a shut plunger. I heard that they are stuck in the last known good idle position from the computer when you take them off. So, maybe that is why this thing never closed? I do know that the stepper motors that are in these IAC valves operate by a predetermined amount of movement from an electrical signal. And I believe that is what has completely FAILED on that O'Reilly part. I did check the resistance between its two terminals and it had the proper specifications. I just find it unbelievable that a supposedly brand new part (it was obviously re manufactured since you could see original part numbers ground off everywhere) could operate so terribly. There is a lack of quality control from some distributors and I believe I have identified some the hard way. Since, I also got my motor mounts there and one of them had the hole drilled in the WRONG place. They overshot the hole on my engine bracket by half. HOW PITIFUL. I returned that one as well, of course and purchased a REAL PART from Autozone. Wow, the pain they have put me through. Just imagine if I were having to pay somebody for labor to do this for me. Then I would have been angry. Now I just find their INCOMPETENCY amusing. LOL.
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Saturday, November 23rd, 2013 AT 1:49 AM
Tiny
MHPAUTOS
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Sorry have been off line due to ongoing internet problems, I live in a remote location and we are the last to get fixed when things go wrong, where are you at with this car? Do you have it sorted yet?
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Tuesday, December 31st, 2013 AT 4:05 PM
Tiny
HASTEWIN
  • MEMBER
Okay, well I checked the fuel pressure the other day, and come to find out it was at a steady 29 psi. The recommended fuel pressure is between 35 and 55. And to be expected is around 45 psi. So I determined that the fuel pump was weak at this point. My symptoms graduated to an intermittent stall, rather than low coasting idle. Which was my only symptoms with the car. So as of right now I just got my new fuel pump in today. And all was going well with the repair today with disconnecting everything, until I go to drop the gas tank. So I have absolutely everything disconnected right now including the straps and the tank will not drop at all! I believe some moron (at Ford) thought it was a great idea to adhere the tank to the bottom of the car with some type of putty or something. It is very cold where I live right now and I believe that is making the adhesive stronger. There is less than 1/8th of a tank of gas in it right now so I have nothing assisting me in getting the tank to come off. So I am going nuts right now because everything has gone smoothly until now. Which, of course is just my luck. The dumb thing won't drop. I have also removed the filler neck from the body of the car and it is mobile. Yet I cannot remove the filler neck from the tank completely yet because the tank won't drop. I am tempted to pry on the tank yet it seems like pretty thin metal. I am also tempted to heat the area around it with a hair dryer. Yet common sense tells me to not mix heat of any form with gasoline. So I am simply stuck as of right now. I cannot wait until it gets warmer outside. So something has to give here. I do get a little mobility out of the tank from the driver side. But the passenger side must be where its adhered more or something. I dunno.
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Tuesday, January 21st, 2014 AT 2:22 PM
Tiny
MHPAUTOS
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I think that if you get it moving it should drop, may be get a friend to add some weight to the pull down force.
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Wednesday, January 22nd, 2014 AT 3:17 AM
Tiny
HASTEWIN
  • MEMBER
Well hello again. I gave a nice tug on the tank yesterday and it came right down, abruptly of course. And for some reason Ford did in fact put glue right in the middle of the tank! Crazy. And I installed the new fuel pump and replaced the fuel tank and lines. And now the car is back to running again. And it no longer stalls! I need to test the fuel pressure again to see what it is running at now. Just because I am curious. There is a slight possibility that the fuel filter is junk or crappy because it is a FRAM brand from walmart. Yeah, I do not have much faith in it, granted it is almost brand new. So the idle while coasting is increasingly becoming normal with the computer relearning things. Just under 1000 RPM is expected when coasting, and around 750 RPM is expected when stopped and idling. However the issue is when I make a slow and sharp turn my idle drops below 600 RPM, but not every time, and of course my brake is applied at this point. So my theories are, its either the power steering fluid is old and dirty (I do not have a power steering pressure switch), or I have a vacuum leak somewhere that I cannot imagine, or my fuel pressure is still restricted due to a FRAM fuel filter. I have flushed the power steering fluid multiple times already and it still appears to be somewhat dark. I am leaning towards there being a hidden vacuum leak somewhere due to the fact that the RPM still does not drop very rapidly like it used to, and that sometimes when I apply the brake the RPM is negatively affected by like 50 RPM. I would not think that it should be affected at all by the brakes. I know the power steering should affect idle a little bit. As for the possibility of a junk fuel filter, I know that would cause all of this with no question. So within the process of elimination, I will begin with the testing the fuel pressure tomorrow, and seeing what I get. If it is still low, I know that it is not the pump or a fuel system sensor. I know that I have a Fuel Pump Driver Module that regulates fuel pressure, rather than a mechanical fuel pressure regulator. My fuel system is a return-less system. I also know that if the FPDM was faulty, the fuel pump would not be driven at all. So it would have to be the fuel filter being defective and causing a restriction. After that, I would guess vacuum leak somewhere very hidden. But I have 22 psi vacuum, so that would be weird because minimal is 17 psi. And, finally its possible my power steering fluid is just not good enough. Other than that, I have absolutely no idea. What are the possible symptoms of dirty power steering fluid? This is crazy because any of these problems would not be detected my the computer, along with any ignition component after the coil pack. I know it can't be a sensor because I would in fact have a check engine light. Based on the symptoms, what are your theories?
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Thursday, January 23rd, 2014 AT 5:33 PM
Tiny
MHPAUTOS
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Change the fuel filter as a matter of course, you need to do this or the pump warranty will be void, check manifold vacuum with a gauge and watch what it shows a vacuum leak will sho up as a change of vacuum if you spray some degreaser around the manifold, is it is some what viscos, the vacuum will stabilise for a second or to as it is drawn into the engine and it will not do any harm as long as you don't start using tin after tin.
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Friday, January 24th, 2014 AT 4:13 PM

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