2.9 engine miss?

[Bronco_Chuck]

have you looked at it in the dark? i had a bad plug that in the dark you could see arcing out. good luck.

 

[Spitfire1975]

I have. No arcing. Wonder if plugged cats could be causing this as well? It just doesn't make any sense that it would CONTINUE to get worse and worse.

 

[Bronco_Chuck]

what octain fule are you using. idealy if the timing was retarded it would make the pinging go away. have you checked the FPR (fuel pressure regulator) my 89 had the crazy idle problem because the FPR was bad.

 

[Spitfire1975]

gonna check that in a minute. Checking how the rail holds pressure over a 30 minute time frame. When I jump the pump at the self test port it has 36 lbs of pressure, but when it is running it has only 30? and when it stumbles in idle the fuel pressure increases to 32lbs??

 

[Spitfire1975]

It has dropped 12 lbs in 30 minutes. Normal? I thought the fuel pressure was supposed to stay built up when the truck was off.

 

[Spitfire1975]

And I use 87 octane. Sometimes 89. ALWAYS Shell or Chevron.

 

[Spitfire1975]

And I try to run some B12 Chemtool through it every 3-4000 miles.

 

[Bronco_Chuck]

i remember reading a TSB that said the pining happens alot with anything over 86 octane. and how about the FPR?

 

[Spitfire1975]

FPR seems fine. No fuel coming out of the vac line. We can't get anything less than 87 octane here. Truck wasn't pinging at all until I tried to give it a tuneup. rail pressure has dropped another 5 lbs in the last half hour. Thats 17 lbs down in an hour.

 

[Spitfire1975]

Where would the pressure be bleeding out from? The tester? No fuel to be seen anywhere. Back through the high pressure pump? Through the injectors?

 

[Bronco_Chuck]

the pressure could be bleeding back through the high pressure pump, but i dont think it would do it that drasticly, could be a bad injector.
if you would just to clarify for me what exactly is it doing? pinging, bad idle, anything else?

 

[Spitfire1975]

When first started (cold) it idles smooth but high (1600-ish). When it starts to go into it's closed loop it starts surging between 600 and 950-ish. Has a sputter to it the whole time. If you let this go on for a few minutes it dies in the low end of the surge. Starts right back up again. When driving......No pinging for the first few miles. As it starts to warm up it starts "pinging" (typical 2.9 ping but worse) to the point where it is seriously affecting driveability. Can't start fast or give it a lot of gas at all. Cruising on flat freeway it doesn't ping UNLESS you try and speed up. Any additional pedal pressure and it is pinging away. Power seems less than it was a week ago before this all started. Gave it a tuneup because it had a random "miss" under load.

 

[Bronco_Chuck]

sorry i totaly missed posts 64 and 65. as far as testing how long it holds pressure i couldnt tell you what its supposed to be. have you done a compression/leak down test? i dont remember if you said you had.

 

[Spitfire1975]

KOEO test only gives me a memory code of 22. KOER test was giving me all sorts of codes. 13, 72, 41, 31, 33. But not always on every test. Most recent was 13 and 72 and 25

 

[Spitfire1975]

No I have not done a compression leakdown. I did a compression test a few thousand miles ago and was at about 150 each, dry, and 160 each, wet. How do I perform the leakdown?