This 2.3 has got me stumped.

[TheTopher]

Isn't 30-40 seconds about how long it takes for an 02 sensor to heat up and start having a say in the fuel mix? Just a thought.

 

[alwayshear]

What kind of oil pressure readings are you getting when it does actually run?

 

[Off Road SHO]

What kind of oil pressure readings are you getting when it does actually run?

It comes off the peg and into the bottom third of the Okay range. No rattling from the rods that we can hear. We haven't been able to rev it any.

It's a 3 wire O2 sensor, but don't know the condition. The PCM didn't show any codes related to it. I might have a spare from an SHO motor that is the same type.

Ah, I just remembered something else...My son cut out the joint in the exhaust pipe between the Catalytic converter and the muffler thinking the cat had disintegrated and was clogging up the muffler. It hadn't and wasn't but we haven't welded the joint back in. So there is just a catalytic converter and then an open pipe. Do you think the lack of back pressure has anything to do with it shutting down after 30 seconds?

The wiring is a big mess with pieced out pieces all over the place, INCLUDING going to the TFI port on the distributor and the coil. As soon as my EVTM gets here, I'll dive into fixing everything; I'm a wiring fanatic.

Tom

 

[Off Road SHO]

Isn't 30-40 seconds about how long it takes for an 02 sensor to heat up and start having a say in the fuel mix? Just a thought.

Ahhh. So if it started sensing a rich condition from say a stuck injector, would the PCM then command way shorted injector pulses to try and lean it back out?

Tom

 

[TheTopher]

Ahhh. So if it started sensing a rich condition from say a stuck injector, would the PCM then command way shorted injector pulses to try and lean it back out?

Tom

Perhaps something along those lines. I'm not entirely sure of the finer points of how that system works, but try unplugging the o2 sensor just for the hell of it and see what happens.

 

[Off Road SHO]

Okay, we un-plugged the O2 sensor and no change; still dies after 30 seconds.

My son was able to keep it running for a longer period of time by pumping the gas pedal and keeping the revs high, but then it eventually quit too.

Timing is at about 12 degrees at idle and at about 16 at 2000 rpm's.

Got the break-out box installed and monitored the ground signal that the computer sends to the fuel pump relay to trip it; we did this to make sure the computer or relay wasn't killing the engine. They aren't. The computer doesn't stop sending the trip ground untill about one second after the engine stops running.

We also pulled off the Idle Speed Control valve/motor and started it up using my thumb as the idle air controller, and were able to see the idle valve opening and closing. Both sides of the valve were clean and not gummed up, so I think that avenue is a dead end.

Still getting the "bad EGR control relay" code due to the bad relay; but we disconnected it and blocked off both vacuum lines and it still dies.

SH*%#)&@

Tom

 

[John Smith]

after it dies will

it start right back up?...and after it dies with the switch still on does the coil have power?...do you have a spare coil?.after it dies does your fuel rail still have presure? and how much?..can u still here the fuel relays with key on?...have you done a key on engine off obd1 code test?...(tech library)..either with a diag reader or CEL light count...you'll get there..is the coil grounded?..

Is the MAP sensor hooked up?...what does the TPS read at thru the cycle?

 

[John Smith]

You prolly alreay are aware of this but...

as a refresher....

http://fordfuelinjection.com/?p=30

grab ur volt meter...

when all else fails...read the plugs..wet?....again secondary fire circuit..?...coil?..

 

[Off Road SHO]

it start right back up?...and after it dies with the switch still on does the coil have power?...do you have a spare coil?.after it dies does your fuel rail still have presure? and how much?..can u still here the fuel relays with key on?...have you done a key on engine off obd1 code test?...(tech library)..either with a diag reader or CEL light count...you'll get there..is the coil grounded?..

Is the MAP sensor hooked up?...what does the TPS read at thru the cycle?

John,

Yep, it starts right back up.

I'll check to see if the coil has power after it dies. Yep It has power as long as the key is on.

I can't remember what the fuel pressure is after it dies, will re-check. Didn't have my lovely assistant tonight, couldn't check fuel pressure.

Are there two fuel relays? I only found one and of course it is hot in run and start but only fires when the Puter sends a ground, activating the relay. And that is working properly.

MAP is hooked up and has been replaced with a new one for Sh!ts and Giggles.

I will check the TPS reporting tonight also. Allrighty then... With key on engine off 1.09 volts; engine at idle, 1.13 volts; engine at about 2000 rpms, 1.50 volts; Even after it dies, if I keep my foot at the same place on the pedal, I still get 1.5 volts. Until I turn it off.

# 1 spark plug has a beige colored insulator but with spots of dark black soot. Plug wires look new.

We used a timing light to tell us that it was firing until after it stopped rotating.


Tom

 

[John Smith]

I was under the impression

that the tps reading should be at about .09-.097 or so throttle closed.
SEE http://fordfuelinjection.com/?p=30

I wish you had a constant fp gauge hooked to the rail so you could observe what it is while running the 30 seconds or so..and what it is when it quits..

remember also this truck has an inertia switch..you're gonna nail this pretty soon..

the EECIV system should have one relay for fuel, one for the pcm, one for the a/c if equipped.

has this truck been running sucessfuly for ANYONE in the last few years?
How about the grounds to the injectors?...

 

[John Smith]

another look at firing issues..

some reading about TFI issues....

"I was driving down the road and the engine cut out. After waiting about an hour, it started back-up and I managed to get it home. This led me to believe the TFI was going bad. I decided to replace the TFI without much thought since I had an extra one having heard stories of the infamous Ford TFI. After the full tune-up (minus the PCV, it is coming in today) the engine was running perfectly--that is for about 20 mins at which time the engine cut out.

Could it be that the Hall Effect Stator has gone bad?

This is common on 2.9 fords,a quick test is after the engine quits,remove the coil wire from the dist. cap hold it about 1/4 inch from a metal surface and crank the engine if it has no spark,remove the spout connector and try again if it has spark there is probably a problem with the ECM,if it has no spark,turn the key to on position,do not crank the engine,wait 1or 2 seconds and turn the key off,if you get a spark the TFI and the coil are good and you need a Hall Effect Stator (pick up coil/PIP)"

Good luck with your efforts..

 

[kimcrwbr1]

Will it run with the spout disconnected. That basically takes the computer advance out of the loop and will run on base timing. As far as I know there is no mechanical advance in the dizzy so the timing should not change at any rpm with the spout wire disconnected. Have you pulled the dizzy and checked the cam gear for wear and end play on the dizzy shaft. It would probably be a good idea to check/change the pickup coil in the dizzy when you have it out. How far is it advanced when you plug the spout back in.

 

[Off Road SHO]

Okay, we just checked it for fuel pressure. After it started right up, we get a solid 25 psi. As soon as it starts to die, it raises up to 35 psi. After it dies, the fuel pressure stayed at 33 psi.

I'm stumped.

Tom

 

[TheTopher]

Okay, we just checked it for fuel pressure. After it started right up, we get a solid 25 psi. As soon as it starts to die, it raises up to 35 psi. After it dies, the fuel pressure stayed at 33 psi.

I'm stumped.

Tom

Check if the injectors are being shut down. Personally I'd test this by pulling the connector off an injector and hook a multimeter to it. (truck should still run on 3 cyl, albeit poorly) Somebody else here May have a better way.

 

[Off Road SHO]

I don't have anything (like a noid light) that will respond quick enough to see the ground that the computer sends to the injector to fire it. I have my break-out box on the computer's harness, so I can try my incandescent trouble light.

Tom