Crank but no start issue on a 95 XL 5.0

[Fatwood61]

Hi everyone. Longtime lurker who has benefited from many posts.

I’ve got a “crank but no start” issue with my 95 Bronco XL 5.0 (225k miles) that has me really banging my head against a wall.

A few months ago I had the old starter go out, so I replaced it, along with the starter solenoid. It worked fine for a while, and then I started getting intermittent no starts, and finally no start at all.

I pulled the ECM and opened it up, after doing some reading about how that could be the problem. There was some obvious corrosion inside, so I sent it off to a company in Florida to be fixed. I figured even if that wasn’t the only problem, the corrosion indicated it needed to be fixed.

I put the fixed ECM back in the vehicle, and it didn’t start. I got a “crank but no start” diagnostic manual from easyautodiagnostics.com, and went through the series of tests he recommends. After putting a probe on the grey/orange wire out of the ICM (attached to the positive terminal), and having someone crank the engine, it started right away. The engine started over and over, even without the probe connected, and I even drove it to the store and back. The next day, nothing again. According to the manual, 99% of the time this indicates a bad PIP sensor on the distributor, so I ordered a new distributor from Rock Auto, marked the positions on the old distributor, and put the new one in. It started immediately, and I thought I was finally there, but then it died in 5 seconds. I couldn’t get it to start after that.

I thought maybe I messed up the timing with the new distributor, so per the Haynes manual, I cranked the engine over to 10 degrees before TDC, marked cylinder 1 on the compression stroke, and pointed the distributor rotor to spark plug 1. Just more cranking, but no start. Everything is getting spark, and there are new plugs, wires, and a new ignition coil.

I could easily be missing some very obvious, simple thing. I’m not very knowledgeable, but have done what I can with the help of manuals and forums like this. If anyone has any directions on where I should look, I would be very grateful.


Additional info: I’m also getting the five chimes indicating something is wrong with the airbag module. I don’t know if this is related, but I don’t know much. Thanks again, everyone.

 

[Tiha]

I have had fuel pumps start and stop like that. Do you have a fuel pressure guage? Might throw one on to make sure you are headed the right direction.

Next, get a spark tester like picture I attached. Put it on, leave it until you get it running consistently. It is a quick easy tool for verifying spark.

 

[Fatwood61]

Thanks, Tiha. I don't have a fuel pressure gauge, but I do have one of those spark testers, and have been using it to check spark on the wires, coil, etc.

 

[Tiha]

Thanks, Tiha. I don't have a fuel pressure gauge, but I do have one of those spark testers, and have been using it to check spark on the wires, coil, etc.

If you push on the schrader valve that you normally hook the fuel pressure gauge to, fuel should shoot up like a foot, rather than just dribble out.

Something to look for even without a gauge.

 

[Fatwood61]

Thanks. I pushed on the valve, and got a spurt that went about a foot, then it just dribbled.

 

[Tiha]

Thanks. I pushed on the valve, and got a spurt that went about a foot, then it just dribbled.

Sounds like you have fuel pressure then.

So are you losing spark?

I am starting to think like Crank sensor or something like that.

 

[Fatwood61]

I'm not losing spark. Is the crank sensor the same thing as the PIP sensor in the distributor? If so, that is brand new. Really appreciate the help.

 

[Tiha]

I'm not losing spark. Is the crank sensor the same thing as the PIP sensor in the distributor? If so, that is brand new. Really appreciate the help.

Teh pip sensor acts like that cam sensor in other engines.
The crank sensor is down on the harmonic balancer.

I need to go look. It has been a long time since I had to deal with that. I think Motech had said something like if it was the crank sensor you wouldn't have spark either.

Have you tried to start in with starting fluid? That might be informative.

Because if you have spark, and it will try to run on starting fluid then the injectors are not firing.

 

[miesk5]

Yo,
See How to Troubleshoot a No Start (Ford 4.9L, 5.0L, 5.8L) by Abraham Torres-Arredondo @ https://troubleshootmyvehicle.com/ford/4.9L-5.0L-5.8L/how-to-troubleshoot-a-no-start-1

 

[Fatwood61]

Thanks. I know what I'm doing when I get home from work!

 

[Fatwood61]

Put a fuel pressure gauge on her, and it showed 28 psi, which is lower than the 35-45 indicated by Abraham Torres Arredondo. I also did the starter fluid test, and it started right up, and immediately died. The inertia switch isn't triggered. I guess I need to test the power into the fuel pump?

I've never done that before. Does it require dropping the tank to test?

Thanks again.

 

[L\Bronco]

Put a fuel pressure gauge on her, and it showed 28 psi, which is lower than the 35-45 indicated by Abraham Torres Arredondo. I also did the starter fluid test, and it started right up, and immediately died. The inertia switch isn't triggered. I guess I need to test the power into the fuel pump?

I've never done that before. Does it require dropping the tank to test?

Thanks again.

It should start at 28 psi, did it stay at 28 while you were trying to start it? (A quick fuel pump check is to remove the gas cap, get your ear as close as you can and have someone cycle the key on and off a couple times, you should hear the pump run for a couple seconds each time it is cycled.)
It sounds like the Pip signal is getting to the ign module but not the PCM. Yours has the remote mounted Ign module from factory correct?
Have you checked for fault codes in the PCM? They will be very helpful in this diagnosis.
Also, is the check engine light on with the key on and engine off?
Thanks (Just need a bit more info before weighing in here.)
Cheers

 

[Fatwood61]

It should start at 28 psi, did it stay at 28 while you were trying to start it? (A quick fuel pump check is to remove the gas cap, get your ear as close as you can and have someone cycle the key on and off a couple times, you should hear the pump run for a couple seconds each time it is cycled.)
It sounds like the Pip signal is getting to the ign module but not the PCM. Yours has the remote mounted Ign module from factory correct?
Have you checked for fault codes in the PCM? They will be very helpful in this diagnosis.
Also, is the check engine light on with the key on and engine off?
Thanks (Just need a bit more info before weighing in here.)
Cheers

Thanks. I actually just went back out with the gauge to check again. It went from 35 to over 40psi when cranked. I also could hear the pump when I put my ear down there and had someone crank. Correct, I have the remote module. The check engine and battery light are on with the key on and engine off. I haven't checked for fault codes in the PCM. Honestly, I am not really sure how to go about doing that. Regarding the PCM, you might have seen above where I mentioned that it had recently had some leaky capacitors replaced, and allegedly the unit was "fixed" and ready to go. I did get it run fine when I ran a probe from the ICM to to battery and had someone crank it. That prompted the new distributor going in, and here I am. Thanks.

 

[L\Bronco]

Thanks. I actually just went back out with the gauge to check again. It went from 35 to over 40psi when cranked. I also could hear the pump when I put my ear down there and had someone crank. Correct, I have the remote module. The check engine and battery light are on with the key on and engine off. I haven't checked for fault codes in the PCM. Honestly, I am not really sure how to go about doing that. Regarding the PCM, you might have seen above where I mentioned that it had recently had some leaky capacitors replaced, and allegedly the unit was "fixed" and ready to go. I did get it run fine when I ran a probe from the ICM to to battery and had someone crank it. That prompted the new distributor going in, and here I am. Thanks.

Thanks
The PIP signal goes from the pickup in the distributor (we called it the stator) to the ign module to make spark 9which you have, it also splices off and goes to the pcm to sequence the injectors (which you have not) the pip is required by the PCM to fire the injectors, so if that wire was broken between the splice and the PCM , you would have spark, but no fuel.
You can listen to the injectors for clicking with a stethoscope or a long screwdriver held firmly against the injector and the bone at the front of your ear, (Sounds weird, but it works)
If they aren't clicking the pip signal may be missing.
I believe your 95 is still OBD1 you can do it with a jumper wire at the self test connector and count the flashes on the check engine light.
Ill look tomorrow when I can get my service info and let you know the exact procedure and a rundown on how to test the pip wire at the PCM.
Cheers

 

[Motech]

After putting a probe on the grey/orange wire out of the ICM (attached to the positive terminal), and having someone crank the engine, it started right away.

That is indeed the PIP output to PCM, and it's a digital, 12 volt square wave signal.

It looks like this:






PIP is both a camshaft AND crankshaft position sensor. Ford did not use a separate crank sensor until OBD II in 1996, and that was ONLY for misfire monitoring.


Here's the basic diagram for your ignition system.



Your probe may have provided the power needed to overcome a poor connection somewhere, like PCM maybe? Or the distributor connector?

Or that splice # S145.

(S145 location, Engine control sensor harness, near T/O PCM)​

​

I doubt that splice, but do not doubt a poor connection, especially any connector you have unplugged many times.

So check first, when no start occurring, does your check engine light stay on while cranking? If so, PCM is not receiving that PIP signal.

If check engine light goes off while cranking, first probe coil negative with test light clipped to battery positive. It should not light up KOEO, but should flash while cranking. If so, then you likely have a bad coil. If not, and if it does not flash, then you're likely missing that PIP signal. If it is lit solid while cranking, you're leaning toward bad PCM.

If no flash, next check all your primary ignition powers and grounds. This is best done with volt-drop testing, second best with volt meter. It can be done with test light too, just know that good results don't tell the whole story with a test light, but bad results do.

These tests must be performed with engine cranking.

Check powers.
With test light clipped to battery negative, probe all red w/ light green wires at coil positive, distributor connector and ICM connector. Should be battery volts KOEO and cranking, though may be a bit dimmer cranking. If light goes out or too dim cranking, go backwards and check same at underhood 20 Amp fuse 'U'.

Check grounds.
With clip on battery positive, probe every black w/ light green wire at distributor connector and ICM connector. Should stay bright at all times, may dim slightly while cranking.

It is imperative that these powers and grounds are in good shape while cranking or you can run yourself in circles replacing PCM, PIP, ICM or... Un huh.

If all above tests good, and no flash on coil negative, try your back-probe on PIP again.
With test light clipped to battery positive, this time go to that grey w/ orange wire at pin 56 on your PCM connector.
Does it flash during cranking and still not start? If so, your PIP is OK, and you'll want to test all PCM powers and ESPECIALLY grounds, because this likely means PCM is shot.

If no flash there, then work your way downstream, to the ICM grey w/ orange. Does it flash there, but not at PCM? Likely the splice I doubted above. No flash? Check it again at distributor connector. No flash there? Check connectors and, if good, get yourself another PIP.

ANOTHER QUICK AND DIRTY TEST THOUGH IS TRY STARTING IT WITH SPOUT DISCONNECTED. IF IT FIRES UP, OR EVEN TRIES TO FIRE BETTER THAN CONNECTED, REPLACE PIP.

 

[L\Bronco]

So check first, when no start occurring, does your check engine light stay on while cranking? If so, PCM is not receiving that PIP signal.

Good call, It runs with starting fluid, so we can assume it has spark. It also makes fuel pressure, so if the data is all accurate, it should be an issue between S 145 and PCM, or the PCM itself (even though it has been sent out, there can still be an issue with it)
Unless I have missed something in this thread?
Good luck
Cheers

 

[Fatwood61]

Really appreciate such detailed feedback. I'm working through it all right now. While I was going through and checking connections, I noticed that the connector where the distributor plugs in has only 5 posts. Is that correct? I appreciate your patience with what is probably a dumb question, but I thought I should ask.

 

[Motech]

I noticed that the connector where the distributor plugs in has only 5 posts. Is that correct?

Yes.

 

[Fatwood61]

Well, she's running...kind of. I went out and was going through all the tests, and when I connected the probe to battery positive and the orange/gray ICM wire, she roared to life immediately. She ran for a while, and sounded rough, then died. I started her a couple of more times (just with the key), and she started fine, but would start to idle really rough, and there was was seemed like a pretty good shake starting when I turned it off. I'm honestly not sure what changed since I last tried to start her. I remember from the Abraham Torres manual that he says starting when you crank with the probe connected to the gray/orange wire is a 99% indicator of a bad PIP. Shouldn't that have been addressed with the new distributor going in? Also, if you gents have any suggestions on where I should start in addressing the rough idle/shake, I would be very grateful. Despite the engine sounding bad, I was so glad to hear that familiar roar! All this detailed feedback has been extremely helpful to a rookie trying to learn. Thanks everyone

 

[Motech]

Also, if you gents have any suggestions on where I should start in addressing the rough idle/shake, I would be very grateful.

As noted above:

ANOTHER QUICK AND DIRTY TEST THOUGH IS TRY STARTING IT WITH SPOUT DISCONNECTED. IF IT FIRES UP, OR EVEN TRIES TO FIRE BETTER THAN CONNECTED, REPLACE PIP.

This also works for poor running too. When you're feeling that "rough idle/shake", unplug SPOUT connector. If it runs better, it's your PIP.