Engine not running

Tiny
DAVIDGORDY
  • MEMBER
  • 1996 DODGE RAM
  • 5.9L
  • V8
  • 2WD
  • AUTOMATIC
  • 215,000 MILES
I have a fuel pump shutoff and electrical problem, I have replaced five fuel pumps to no avail. Fuel pressure at rail is 49 PSI, yet when key is turned on fuel pump runs and does not shut off at prescribed pressure of 49-50 PSI. If I cycle the key say 25 to 50 times giving a six second delay between cycles eventually the fuel pump will stop after the key is energized and the truck will start and run fine. But, after it is shut off and cools the cycle starts all over. Another symptom is that while the truck is in a no start condition I get a Data Link Error on the code reader (Autel). But as soon as the problem clears, Data Link is restored and no codes. I have replaced five pumps, purge valve, vapor canister which was bad, all eight injectors and fuses.
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Saturday, September 22nd, 2018 AT 10:11 AM

171 Replies

Tiny
KEN
  • ADMIN
Two things come to mind which are the fuel pump relay and auto shutdown relay. I would remove them to check for heat damage. Also here is a guide that can help you test them and the location of the relays also I have included the engine wiring diagrams so you can see how the system works:

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

Check out the diagrams (below). Please let us know what happens.

Cheers, Ken
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Monday, September 24th, 2018 AT 12:46 PM
Tiny
DAVIDGORDY
  • MEMBER
Already Replaced both. This is the fifth fuel pump and regulator in the truck now.
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Monday, September 24th, 2018 AT 2:05 PM
Tiny
KEN
  • ADMIN
Both relays? If so please bypass the fuel pump relay (hot wire) to see if the truck starts and runs okay. Connect terminals 30 and 87.
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Tuesday, September 25th, 2018 AT 9:30 AM
Tiny
DAVIDGORDY
  • MEMBER
Bypassed the fuel relay 87 to 30 and it just turns the pump on as if the relay was there and the key was on. Still not turning on coil and injectors.
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Wednesday, September 26th, 2018 AT 12:22 PM
Tiny
KEN
  • ADMIN
Can you do the same with the ASD relay? It sounds like the PCM maybe bad. Lets use this guide and the wiring diagrams from above to check the wiring.

https://www.2carpros.com/articles/how-to-check-wiring

If everything checks out I would get a used PCM and replace it. Here is the location and pin out for the computer

Check out the diagrams (below). Please let us know what happens.
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Thursday, September 27th, 2018 AT 10:07 AM
Tiny
DAVIDGORDY
  • MEMBER
I have done both.
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Thursday, September 27th, 2018 AT 4:30 PM
Tiny
KEN
  • ADMIN
The data error code is making me think the PCM is bad. If you bypass the fuel pump relay does the fuel pressure stay good and not fall off?
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Friday, September 28th, 2018 AT 11:51 AM
Tiny
DAVIDGORDY
  • MEMBER
Stays at 49-50 PSI.
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Friday, September 28th, 2018 AT 11:54 AM
Tiny
KEN
  • ADMIN
Does it run okay with the bypass? Can you please shoot a quick video with your phone so we can see what is going on? That would be great. You can upload it here with your response.
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Friday, September 28th, 2018 AT 12:02 PM
Tiny
DAVIDGORDY
  • MEMBER
It does not start with any bypass. So, no.
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Friday, September 28th, 2018 AT 12:03 PM
Tiny
KEN
  • ADMIN
Will it run will starting fluid? Here is a guide that can help us, does it have spark?

https://www.2carpros.com/articles/car-cranks-but-wont-start

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Saturday, September 29th, 2018 AT 11:15 AM
Tiny
DAVIDGORDY
  • MEMBER
No, it does not have spark.
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Saturday, September 29th, 2018 AT 11:16 AM
Tiny
KEN
  • ADMIN
Yep the link error is telling us the computer is having a problem if you have check the wiring I would say the PCM has gone out. I would try a used one and plug it in to see what happens.
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Saturday, September 29th, 2018 AT 11:41 AM
Tiny
DAVIDGORDY
  • MEMBER
Just ordered one.
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Saturday, September 29th, 2018 AT 2:17 PM
Tiny
KEN
  • ADMIN
Nice, let us know
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Sunday, September 30th, 2018 AT 11:21 AM
Tiny
DAVIDGORDY
  • MEMBER
Ken, you were correct. The Re man ECM arrived pre-programmed today. I spent an entire five minutes installing it. Said a prayer and turned the key to the on position. The fuel pump primed and shut off as it should so I turned the key to start and it started immediately. It would not idle at first but after keeping it running for one minute with the accelerator until all the fuel components could properly charge and get rid of the air, and also the ECM could make adjustments, All is well. Runs like a champ! Thanks again my friend!
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Wednesday, October 3rd, 2018 AT 12:43 PM
Tiny
KEN
  • ADMIN
Glad you could get it fixed, that kind of problem can be tough. Please use 2CarPros anytime we are here to help

Cheers, Ken
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Thursday, October 4th, 2018 AT 10:30 AM
Tiny
CODY EPLEY
  • MEMBER
  • 1996 DODGE RAM
  • 8.0L
  • V10
  • 4WD
  • AUTOMATIC
  • 167,000 MILES
I have replaced ECM, crankshaft sensor, purge solenoid, fuel pump and pretty much every fuse an relay. I cannot get my truck to run. I have strong fuel pressure all the way through the line. No spark at coils, but cannot fix that until I figure out my main issue. My ASD and fuel pump relay are clicking on the distribution panel. I have also heard the solenoid clicking with them under the intake. I am not very strong in electrical but as far a mechanical I cannot think or find the issue. I cannot get a code from the new ECM because the computer has not ran through a full cycle on the truck. If you can help me or point me in the right direction other than the dealer who wants to charge me $260.00 for diagnostics or give me $11,000 for trade in I want my truck to keep going. I faced the hard ship of finding the rare crank sensor and ECM.
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Thursday, October 4th, 2018 AT 10:32 AM (Merged)
Tiny
CARADIODOC
  • EXPERT
You replaced the Engine Computer. That means the 12 volt memory circuit was bad. That is why there are no fault codes. Removing the computer or disconnecting the battery erases the codes, then that valuable information is lost. Resetting fault codes has nothing to do with a drive cycle, although some defects are only detected under certain driving conditions. That can include codes related to the crankshaft position sensor and camshaft position sensor. Often the missing signal from one of those is only detected while the stalling engine is coasting to a stop. Those codes may not set by simply cranking the engine. You need a scanner to view live data to see if those signals are arriving at the Engine Computer. I have a Chrysler DRB3 scanner for all of my vehicles. That lists each sensor with a "No" or "Present" during cranking. Codes for electrical problems, like cut or grounded wires, and some sensor failures, will be detected the instant you turn on the ignition switch, and the fault codes will set at that time. Do you know how to read the codes yourself without a scanner?

You can verify if one of those sensor signals is missing without a scanner. Use a test light to check for the 12 volts. Most digital voltmeters do not respond fast enough for this test. Back-probe through the electrical connector for either coil pack, any injector, or either of the two smaller terminals on the back of the alternator. The correct wire is the one that is the same color at the coils and every injector. Typically that is the dark green/orange wire. You will see the test light turn on for one second when you turn on the ignition switch. What is important is if it turns on again during cranking.

If you do not get 12 volts during cranking, you will not have spark, injector pulses, or fuel pump.
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Thursday, October 4th, 2018 AT 10:32 AM (Merged)
Tiny
CODY EPLEY
  • MEMBER
I replaced the ECM because there was no communications from the old one to the scanner. I replaced it and now the ASD relay along with fuel pump relay are clicking. I have been checking wires with volt meter and the power is not reaching the coils or letting fuel past the injectors but supplying plenty of pressure in the line all the way to the injectors. Only code it gave me was P0335 for the crank sensor so after replacing it now no codes other than my 3-4 shift solenoid show up. The relays still click and wont allow start up. I have read a lot of the forums talking about certain wires coming lose or becoming pinched. My first computer did not go out till after I hit a large puddle after a rain storm. I found no way for water to get to the ECM or any close connections. I later replaced that ECM with a used one and the truck fired right up. After a month I washed the truck and only washed from back of cab to front and under when I tried starting it would not run so I checked some ground wires and tightened then the truck fired up but just down the street is started to miss and shut off. If I let it sit for two to three minutes it would start and run for five to ten minutes then the relays click and shut off the truck. I could get it to run after letting it sit but once it got to running temperature it shuts off. I took it to the dealer and they drained my battery and only tested the distribution box then wanted $600.00 more to go on I told them no. Went to pick it up and could not start it cause they drained the battery I had to buy a new one cause they collapsed a cell. After all this now I am stuck with no fire but will turn with no problem. So I am looking for help figuring the area to look in or maybe someone knows a common issue I can begin my search with.
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Thursday, October 4th, 2018 AT 10:32 AM (Merged)

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