This truck is killing me! Have fuel, air, spark and compression

[Rusty Shackleford Gribble]

1991 2.9. Hello ranger friends. Hoping someone can help get rid of my insanity! Here’s what happened. Out driving one day and it started to either misfire or die out. It was hesitating badly. Jerking me in my seat. Made it home and tried to start it the next day. It struggled (fired here and there) but wouldn’t start. Couple days later, nothing. No spit. No sputter. Just cranks endlessly. Here’s what I’ve done. Verified fuel pressure at the rail at 40psi. Plugs are wet with gas when pulled and has a new pump/filter so I don’t think it’s fuel. Won’t even get a pop or attempt to go with ether in the intake. It’s got new wires, plugs, cap, coil, rotor, TFI and battery. Was running fine on all the new parts for quite a while. I tested for spark from the coil and got it. Same from the plugs. Seems good. Thought it might be timing so pulled the plugs, rotated the motor to TDC and made sure the rotor was pointing to cyl 1. I am going nuts trying to think of anything else! A friend mentioned it could be a temp sensor telling the computer it is too cold so then overfueling? I replaced both temp sensors at the top of the T stat.

 

[Rusty Shackleford Gribble]

Oh. And working on a better compression test. So I have a kit but the threads are not long enough to catch. I used the rubber plug you hold with your hand. It blew my hand back and the gauge read 90 psi so I assume it’s more than that. What baffles me is it won’t even sputter or backfire with starting fluid. That’s why I’m wondering if my friends theory about too much fuel could be the culprit.

 

[Brain75]

from the jerking violently and all the other cough sputter, not even trying to start I would say it acts kinda like the timing slipped a couple teeth. Compression test would be my 1st to see if the timing is fouled up... might even be tempted to pull the valve covers and just quick look for busted springs or other catastrophic damage - but compression should reveal those first.

not even trying on ether says the issue isn't in fuel system, plugs being wet says you are getting fuel where it needs to be.

Did you try to pull codes? Tougher to do on a obd 1 than obd 2, but they will tell ya a lot.

 

[Rusty Shackleford Gribble]

Thanks for your reply!!!! I did pull the codes. I got 21, 24 and 67. From what I was able to gather, 21 and 24 can be ignored since when I pulled the codes, the engine was not warm. I get mixed opinions on 67 which is the clutch sensor. I saw some people said that it could cause a no start. Others say no since mine is a manual tranny and I didn’t have the clutch depressed when pulling the codes. I would assume I could ignore it since I am able to crank and I’m getting spark? Also, any insight on whether my friends theory could be a possibility on a temp sensor? That would make sense since I am getting a code for that but again most people said to ignore that code. Thanks again!

 

[Uncle Gump]

Disable fuel... and spark

Pull plugs...

Crank it over to clear the flooded condition.

Install clean dry plugs... enable spark and fuel.

Start it up.

They don't like to fire if too wet.

Also... spark timing is worth a look. Is the distributor tightened down... or will it move?

 

[Rusty Shackleford Gribble]

Disable fuel... and spark

Pull plugs...

Crank it over to clear the flooded condition.

Install clean dry plugs... enable spark and fuel.

Start it up.

They don't like to fire if too wet.

Also... spark timing is worth a look. Is the distributor tightened down... or will it move?

Good call on disabling fuel. I might try that but only run ether, as if it’s a flooding condition, whatever is happening will just happen again. That said, I did replace the plugs again recently but didn’t disable fuel at the time. I assume I can just yank the inertia switch to do that.

 

[Uncle Gump]

Fuel pump relay...

 

[Rusty Shackleford Gribble]

Disable fuel... and spark

Pull plugs...

Crank it over to clear the flooded condition.

Install clean dry plugs... enable spark and fuel.

Start it up.

They don't like to fire if too wet.

Also... spark timing is worth a look. Is the distributor tightened down... or will it move?

Distributor doesn’t move. I wiggled it pretty hard. Same with the cap. I’ll have to get my hands on a light to check timing precisely but I did cold time it.

 

[Rusty Shackleford Gribble]

Fuel pump relay...

Is that better than pulling the inertia switch? I only ask because that’s much easier to get to than the relay.

 

[Rusty Shackleford Gribble]

Disable fuel... and spark

Pull plugs...

Crank it over to clear the flooded condition.

Install clean dry plugs... enable spark and fuel.

Start it up.

They don't like to fire if too wet.

Also... spark timing is worth a look. Is the distributor tightened down... or will it move?

Update. I got it to run with ether. I pulled all the plugs. Let the fuel clear. With the pump disabled, I sprayed ether in the intake. Nothing first go round but then I remember something about a spout connector. I removed that and it started up. Ran until the ether ran out. So, then I tried it again with more ether. This time, I plugged the fuel pump back in while it was running. It changed from running ok to running rough. I had to keep giving it gas to keep it going. Then I tried once more. This time, ran it with ether and then plugged in the spout connector. It died right away. As soon as I plugged it in. Any ideas would be greatly appreciated and thanks sooooooooo much for your help so far!

 

[gaz]

@Rusty Shackleford Gribble
Unplugging the spout connector permits the base timing to be adjusted without the PCM changing it.
Plugging in the spout connector puts the PCM back in charge. I would look at the Power Control Module (PCM) if I knew that my fuel supply and system is good..

 

[Rusty Shackleford Gribble]

@Rusty Shackleford Gribble
Unplugging the spout connector permits the base timing to be adjusted without the PCM changing it.
Plugging in the spout connector puts the PCM back in charge. I would look at the Power Control Module (PCM) if I knew that my fuel supply and system is good..

Thanks! I was going to go get and swap the ECM but I was thinking it could also be the crankshaft position sensor if these 2.9s have one. Do you or anybody know if they do or is that handled by the TFI module? Thanks again.

 

[gaz]

The 2.9l does not use a crankshaft position sensor, the distributor makes the timing signal with the hall effect sensor.

 

[Rusty Shackleford Gribble]

The 2.9l does not use a crankshaft position sensor, the distributor makes the timing signal with the hall effect sensor.

Thank you for the info! I scoured the web and found mixed answers. Even more confusing, Rock Auto offers one for my 2.9. Well then, I replaced pretty much everything aside from the distributor and ECM. I ordered an ECM and am praying that’s the issue. The distributor does not look fun to change at all! I had a hard enough time with the cap and TFI. Much appreciated.

 

[gaz]

@Rusty Shackleford Gribble
I'm no fan of troubleshooting with new components but I would change the Hall Effect sensor in the distributor, before I bought a replacement PCM. It is an inexpensive Win/wiN.

If open up your PCM, take some detailed pics and post them on here, you might learn what fails on to these PCM's.