The engine cranks but will not start?

Tiny
TIM HURLEY
  • MEMBER
  • 1988 FORD F-150
  • 5.0L
  • V8
  • 2WD
  • AUTOMATIC
  • 200,000 MILES
This truck was hard to start when cold and had an erratic idle. I decided to give it a little tune up. After changing a solenoid relay and plugs and wires distributor cap and rotor it now will not start. I checked several times to make sure all wires were in place and on the distributor cap like they should be. It acts like timing is way off. Don't know how that would happen I did not turn it over when I had distributor cap off. The truck did have some strange electrical issues like if the radio was on and you turn the headlights on the radio would go off. I am wondering if in the process if I did not short something out and it fried the EEC. Have you heard of a engine jumping timing like that? I have spark and I have fuel pressure.
Wednesday, September 4th, 2019 AT 9:34 AM

13 Replies

Tiny
BMDOUBLE
  • MECHANIC
  • 1,139 POSTS
I would have went a different route if you had not mentioned the electrical issues you've had, which is great for you to mention by the way! This ignition system does not do well when there are grounding issues and these older truck are plagued by ground issues. A quick test is to hook a jumper cable from the battery negative to the frame and another from the negative cable to the distributor case or the engine near the distributor. If the profile ignition pickup signal does not get pulled down to 0 volts (ground) the coil cannot charge for the next spark to occur, or any spark for that matter. I would attach a guide but I don't want you to waste your time doing anything other than this test. This guide can help us fix it

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

Check out the diagrams (Below). Please let us know what you find. We are interested to see what it is.
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Monday, May 31st, 2021 AT 12:47 PM
Tiny
TIM HURLEY
  • MEMBER
  • 9 POSTS
Are you talking about my in-dash voltmeter should go to zero with the key on?
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Monday, May 31st, 2021 AT 12:47 PM
Tiny
TIM HURLEY
  • MEMBER
  • 9 POSTS
I forgot to mention that I did replace the ignition control module when I first had this problem.
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Monday, May 31st, 2021 AT 12:47 PM
Tiny
BMDOUBLE
  • MECHANIC
  • 1,139 POSTS
No sir, a handheld voltmeter if you have one. We just need to make sure that you have good voltage available and a good ground also. If you have a test light, don't use it because we need a reading of the actual voltage available.
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Monday, May 31st, 2021 AT 12:47 PM
Tiny
TIM HURLEY
  • MEMBER
  • 9 POSTS
Okay I will get right on that in the morning since I am at work now. Thank you and I will let you know what the results are.
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Monday, May 31st, 2021 AT 12:47 PM
Tiny
TIM HURLEY
  • MEMBER
  • 9 POSTS
I did the testing as you described. I had readings that were all over the place. The readings were 6.5 volts in one area and as little as.01 in another. I also had readings as high as 12.60. I looked under the truck and found that the braided grounding straps were rusted badly and. The mounting surfaces were also. The negative battery cable looked okay but I am going to replace it with a 2 gauge wire.I will replace or clean up the rusty straps and grind the rust off of mating surface. Then do the test over again. Does that seem to be the way to proceed?
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Monday, May 31st, 2021 AT 12:47 PM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 42,973 POSTS
If I can jump in here. That is exactly what I would do. Good grounds from the battery to the engine and frame/body is what needs to be fixed checked. Please let us know.
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Monday, May 31st, 2021 AT 12:47 PM
Tiny
TIM HURLEY
  • MEMBER
  • 9 POSTS
Okay after a few repairs on the ground seems to be fine. I decided to check the timing by lining up my pointer and the zero TDC line on the HB. I did have to move the distributor. Now number one cylinder on the cap is at the 12 position and all of the illustrations I have seen show in the one o clock. Position. Also I have number one plug two positions away from the hold down clip just like the drawings show. Another issue I now have is I was getting a click from the fuel pump relay even though pressure was only showing 22 PSI. I had already obtained a new eec computer and after installing I have no power to the relay now. I removed the old pump and it is working when I hooked it to the battery. I have a new pump that I am going to install probably anyway but that should have nothing to do with power to the relay is that correct? I am probably jumping around too much instead of fixing one issue at a time.
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Monday, May 31st, 2021 AT 12:47 PM
Tiny
TIM HURLEY
  • MEMBER
  • 9 POSTS
Okay after a few repairs on the ground seems to be fine. I decided to check the timing by lining up my pointer and the zero TDC line on the HB. I did have to move the distributor. Now number one cylinder on the cap is at the 12 position and all of the illustrations I have seen show in the one o clock. Position. Also I have number one plug two positions away from the hold down clip clip just like the drawings show. Another issue I now have is I was getting a click from the fuel pump relay even though pressure was only showing 22 PSI. I had already obtained a new EEC computer and after installing I have no power to the relay now. I removed the old pump and it is working when I hooked it to the battery. I have a new pump that I am going to install probably anyway but that should have nothing to do with power to the relay is that correct? I am probably jumping around too much instead of fixing one issue at a time.
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Monday, May 31st, 2021 AT 12:47 PM
Tiny
TIM HURLEY
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  • 9 POSTS
I forgot to mention that I did test the wire that to the relay that is supposed to be hot all the time and it was.
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Monday, May 31st, 2021 AT 12:47 PM
Tiny
BMDOUBLE
  • MECHANIC
  • 1,139 POSTS
Okay, does your service engine soon light illuminate when you turn the key to the on position? If it doesn't then your power-train control module is not energizing the PCM relay which is necessary for the fuel pump relay to energize also. Put the old PCM back in it and see if the fuel pump relay energizes, if it does then either the PCM is bad or the application is incorrect. There should be 2 hots at the PCM power relay (12 volts), if there are 2 hots, ground the tan/light green wire. If it energizes, the issue is either the PCM or the circuit. But with the grounding issues that you've had, I would look for more bad grounds or add more grounds. I've illustrated the power-train controls diagram with some key things to check, be sure to check the brown fusible link at the starter solenoid as this supplies the PCM relay with 12 volts. If it's broken or burned through, parts stores sell small rolls of it, just splice in a new one with an eye terminal. I also included a load test with a headlight bulb for the grounds, if you have a spare one anyways. Let us know what you find!
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Monday, May 31st, 2021 AT 12:47 PM
Tiny
TIM HURLEY
  • MEMBER
  • 9 POSTS
It will probably be a couple days before I can get back to testing but I will let you know what I find. I can tell you that unfortunately I took the old computer back already for the core charge. I see now that was a mistake. The EEC relay seems to be working fine it is clicking when I turn the key. I should have time to bench test the fuel pump relay even though it is new. Thanks for all your help I will get back with you later.
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Monday, May 31st, 2021 AT 12:47 PM
Tiny
BMDOUBLE
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Okay, no problem!
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Monday, May 31st, 2021 AT 12:47 PM

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