Engine will not start?

Tiny
68GTOCONV1
  • MEMBER
Yes, I replaced the engine and all sensors are new I even warrantied them out and replaced them again. All gauges work, tachometer does not bounce when cranking. ASD clicks on. All pin checks are good. I am about to ripe apart harness to see if I have a broken wire, but this thing has me very flustered.
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Thursday, September 24th, 2020 AT 6:18 PM (Merged)
Tiny
68GTOCONV1
  • MEMBER
Also, I can't remember if I should have constant power at pdb under hood with key off because currently I do.
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Thursday, September 24th, 2020 AT 6:18 PM (Merged)
Tiny
KASEKENNY1
  • EXPERT
Are you referring to the Power Distribution Center (PDC)? And when you say constant power, you mean on the feed wire from the battery? If so, then yes. This is normal.

Did this issue start after the motor replacement? Meaning did you do the engine and then this happened or has it been running since the engine has been put in? In other words, has it ever run since you replace the engine?
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Thursday, September 24th, 2020 AT 6:18 PM (Merged)
Tiny
68GTOCONV1
  • MEMBER
Yes, the vehicle ran great for about 4 months and all the fuses in the PDC have power all the time key on or key off doesn't matter. It ran great then had I little stumble and then shut off no spark and no injector pulse.
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Thursday, September 24th, 2020 AT 6:18 PM (Merged)
Tiny
KASEKENNY1
  • EXPERT
Okay. I suspect the PCM is the issue if you have no spark or fuel and it is getting a crank signal.

Run through this test or just jump to step 7 and run that jumper and see if you get spark. If you do then you need a PCM and that may fix both issues.
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Thursday, September 24th, 2020 AT 6:18 PM (Merged)
Tiny
JOE200353
  • MEMBER
  • 1997 JEEP WRANGLER
  • 4 CYL
  • 4WD
  • MANUAL
  • 160,000 MILES
My jeep was struck and dented in the gas tank area. There was no leaking of fuel and the vehicle otherwise appears ok but will not start. I was told the fuel pump may have automatically cut-off and must be re-set. Is this something I can do myself? Is there a re-set button? Jeep cranks but will not turn over. Thanks.
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Thursday, September 24th, 2020 AT 6:19 PM (Merged)
Tiny
RACEFAN966
  • EXPERT
Ok from what I can find no inertia switch all I find is a fuel pump relay and fuel pump module. Now the module is on top of the fuel tank or part of the fuel pump may be damaged. So if you would like I can send you procedure to check the relay if you like and you can check it just to be sure it is good. But you will have to get to the top of the tank or pull the fuel pump to check the module. Let me know what you want to do.
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Thursday, September 24th, 2020 AT 6:19 PM (Merged)
Tiny
JOE200353
  • MEMBER
The procedure to check the relay would be helpful. Not sure how that is done here. My email is the same as my user name @yahoo. Com if needed. Thanks.
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Thursday, September 24th, 2020 AT 6:19 PM (Merged)
Tiny
RACEFAN966
  • EXPERT
You will need a digital multi meter first. Now you need to unplug the fuel pump relay check for continuity between term. 87a and 30 there should be no continuity.
Now you will need to build a couple of jumper wires for the relay ok. Now from the possitive side of batt. to term. 86 and neg. side of batt to term 85 now there should be continuity between term. 30 and 87, and no continuity between term 87a and 30 if you find anything other then replace the relay. Here is a pic of the relay so you know which term it which ok. Let me know how it goes.


https://www.2carpros.com/forum/automotive_pictures/249564_fuel_pump_relay_1.jpg

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Thursday, September 24th, 2020 AT 6:19 PM (Merged)
Tiny
TBRINKMEYER
  • MEMBER
  • 1997 JEEP WRANGLER
  • 4.0L
  • 6 CYL
  • 4WD
  • MANUAL
  • 160,000 MILES
Hadn't had any problems up until a couple weeks ago my vehicle wouldn't start. The battery is strong, the starter turns over fine but won't fire. However, when the ignition is on the battery and fuel gauge don't respond. Based on this other troubleshooting suggest that it's likely the CPS but when disconnecting the CPS wire connection the gauges still don't respond. I also used an ohm meter to make sure the CPS was reading as it should and it checked out fine. I've checked all fuses and any same relays I've exchanged location with no success. I checked the ignition coil ohm reading and it's checked out fine. Spark plugs were changed out at around 150,000 miles and the fuel pump was changed out around 135,000 miles. When turning on the ignition listening for the fuel pump I can't hear it activate for a few seconds as I should. So I disconnected the fuel pump wiring are the rear of the vehicle and checked the meter readings and it doesn't seem to be getting power. I inspected the fuel pump wiring from the rear to the front and found no damage. I've tried using a diagnostic FIXD but it requires the vehicle to be running to get a read.

I don't know what else I can check other than I could spray starter fluid into the intake to get it to briefly start but I'm certain that would work. It seems that it's electrical but I've not found any culprits. Please let me know if there's anything else I can look into. Thanks.
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Thursday, September 24th, 2020 AT 6:19 PM (Merged)
Tiny
ASEMASTER6371
  • EXPERT
Good morning,

An ohmmeter is not a test for the signal from the crank sensor. What you need to do is to crank the engine and see if you get an RPM reading either on a scan tool or on the tachometer on the dash if you have one.

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

The crank sensor is a very common failure for no start but has no effect on the dash cluster.

If you spray starter fluid into the intake and it starts and stall, that will tell you that you have spark and that you have a fuel delivery issue. Try this test.

I would also check the actual fuel pressure to be sure it is supplying the correct pressure.

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

Roy
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Thursday, September 24th, 2020 AT 6:19 PM (Merged)
Tiny
ADHJEEP
  • MEMBER
  • 1997 JEEP WRANGLER
  • 6 CYL
  • 4WD
  • MANUAL
  • 77,000 MILES
Engine will not start. Checked and found no spark, replaced coil, wires, cap and rotor, still no spark. Getting fuel pressure at the injector bar. Not getting 12 volts at the coil. Checked the ASD relay swapped it with the one for the AC, still no 12 volts at the coil. Check fuse 11, 3 and 6, all good. Checked voltage at ASD relay, get 12 volts on the relay coil when ignition swiitch is turned on, 12 volts is present at the input to the relay switch, but the relay does not pick. Appears no ground is coming from the PCM. Suspect the PCM, but would like input from anyone who had this problem before. Engine cranks over fine but does not start.
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Thursday, September 24th, 2020 AT 6:19 PM (Merged)
Tiny
CARADIODOC
  • EXPERT
The 12 volts at the coil for one to two seconds after turning on the ignition switch proves the ASD circuit is working properly. After that, the ASD relay will not turn on again until the engne computer sees engine rotation, (cranking or running). It powers the coil(s), injectors, fuel pump or pump relay, alternator field, and oxygen sensor heaters.

The engine computer knows the engine is rotating by the pulses from the crankshaft position sensor, a common falure item.

Caradiodoc
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Thursday, September 24th, 2020 AT 6:20 PM (Merged)
Tiny
ADHJEEP
  • MEMBER
Replaced the cracnkshaft position sensor, still will not start and not getting any spark
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Thursday, September 24th, 2020 AT 6:20 PM (Merged)
Tiny
CARADIODOC
  • EXPERT
Let me clarify my earlier reply. Check for 12 volts at the ignition coil for the first second after turning on the ignition switch. If you turn the switch on, then run to the front of the vehicle, there will not be voltage on the coil. It is only there for one second, so you'll need a helper to turn the switch or you'll need to prop the meter or test light so you can see it from inside the vehicle. If you never see voltage there, I would first suspect my probe wasn't making good contact with the terminal. If there still isn't voltage, suspect the ASD relay, which you already switched, or the wiring to the coil. The Engine Computer is next, but I'd be surprised if he was the problem.

If the voltage is there for the first second, it must come back during cranking. If it doesn't, that's the time to head to the crankshaft position sensor. Since that didn't help, the next thing to try is the camshaft position sensor. According to Chrysler, his purpose is for synchronizing fuel injectors, but on Chrysler vehicles, this sensor will result in no spark AND no fuel if it is defective.

The cam sensor is in the distributor. You can test it with an old pointer-type voltmeter. The signal wire voltage should pulse between 0 and 5 volts during cranking. If it doesn't, replace that sucker.

Caradiodoc
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Thursday, September 24th, 2020 AT 6:20 PM (Merged)
Tiny
ADHJEEP
  • MEMBER
Ok, so the camshaft position sensor did not fix the problem. I put a voltmeter on the wire to the coil that should have 12 volts on it for at least 1 or 2 seconds. I see about 1.2 volts. I disconnected pulled the ASD relay and put a jumper across the contacts expecting 12 volts at the coil, just a few millivolts is showing. I checked the voltage at the connector near the PCM, saw 12 volts when the connector was separated. I disconnected all the fuel injectors because they are part of the 12 volt circuit from the ASD (thought maybe a short in the injector could be pulling the voltage down, no change. Thinking maybe one of the O2 sensors could be cause a problem? They are feed 12 volts from the ASD?
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Thursday, September 24th, 2020 AT 6:20 PM (Merged)
Tiny
CARADIODOC
  • EXPERT
Based on some observations in your first post, I'm going to strongly suggest there is nothing shorted. If you have 12 volts feeding the contacts of the ASD relay, a fuse would have blown when the relay turned on or when you bypassed it.

If I found 1.2 volts at the coil, I would first suspect my meter probe wasn't making good contact with the terminal. After scratching it around a little, and I still had 1.2 volts, I would measure on one of the injector connectors. If you find 1.2 volts there too, ... Happy day! Suspect a break in that wire. The splice would be a logical spot to look. Coroded splices are especially likely to cause some items on a circuit to have power while other items are dead.

Caradiodoc
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Thursday, September 24th, 2020 AT 6:20 PM (Merged)
Tiny
IBANEZJEEPGUY
  • MEMBER
I've spent the better part of today diagnosing the same problem. Vehicle is 2000 Wrangler with the 2.5.
Problem is no starting on crank. Looked for 12v at coil but found nothing, no on key on and not while cranking. Tested the other lead back to ground and I got continuity back to all grounds so I knew the computer could control the coil. Tested for 5v reference at crank & cam sensors, those were good.
To verify anything obvious as being faulty I temporarily hooked up a direct 12v wire lead from the battery to the coil green wire, cranked up the Jeep and it ran! Woohoo. I have no idea where the coil's green wire goes or what controls its voltage but to my knowledge this vehicle's ASD system is functioning properly because all the injectors are firing now.
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Thursday, September 24th, 2020 AT 6:20 PM (Merged)
Tiny
ADHJEEP
  • MEMBER
Ends up that the problem was the wire from fuse 6 in the power diistribution center going to the contact side of the ASD was broken, actually it is the wire the comes out of the fuse side of fuse 6 it's a red and white wire, goes past the battery and is spliced at S100 just before the Power Control Module. Must have been a drop of battery acid that spilled on the wire bundle some time ago and worked its way into protective cover of the bundle eventually it burned thru the insulation and then the wire. This is the 12 volt supply to the contact side of the ASD which powers the coil, injectors and the PCM. Re-spliced the wire and everything works fine.
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Thursday, September 24th, 2020 AT 6:20 PM (Merged)
Tiny
CARADIODOC
  • EXPERT
Wonderful. One more veehickel fixed.

How are you doing with yours ibanezjeepguy?

Caradiodoc
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Thursday, September 24th, 2020 AT 6:20 PM (Merged)

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