REPLACE the PLATS!

 

plan on doing that first thing tonite, but while i was there i was going to get a coolant sensor if i thought it needed it. i live to far away from town

 

Does it show any codes? If not get a gauge and check fuel pressure.

 

done that. 32 psi. I have done everything

 

Should be 32-35psi with vacuum on the FPR and 40psi without and it should hold this pressure when the engine is off, if it doesn't you may have a stuck injector. Also check for the presence of gas in the vacuum line from the FPR, and for gas in the vacuum lines from the charcoal canister. If you have dual tanks and the crossflow problem gas can be pulled through the tank vent system and into the intake.

 

well i don't have gas coming through the vacuum line at the FPR. I can check fuel pressure when un hooked. The injecter better not be stuck. there brand new!! Also my charcol cans are not hooked up. I dont want them hooked up and never have had them hooked up.

 

so how about a 91 4.9 with a dead #3 cylinder...i just started at a new shop, this truck was there for three months before me. boss told me to mess with it and see if i could figure it out. last tech threw everything in the book at it...i haven't gotten as far to confirm or rejects his findings....here's what he did...

plugs - autolite's non platinum.
wires - motorcraft
cap and rotor - motorcraft
ignition module
map sensor
02 sensor tps sensor
checked fuel pressure and leakdown - ok
compression check - ok
checked fuel injectors - ok
checked injector harness with noid light - ok
boneyard ecm - no change
spark on all plugs from distributor no wires touching, routing fine
coil
air filter
checked for vacuum leak - ok
checked timing - ok
checked coolant system for leaks - ok
pulled intake and valve cover - all rockers move and engine cranks smoothly

however, when you start it, it cranks smoothly, then starts up rough, smooths out to simply a noticeable miss. pull #3 plug wire = no change in idle, pull #3 injector connector, no change in idle...would a burnt valve be the culprit?? even though it compression tested ok?

i come to you now because i am out of ideas honestly...when i check this stuff i wanna be sure about it...i've checked the spark, i set the timing (pulled front cover and everything to make sure no broken teeth on gears) i checked the injector and it's wires today with the noid light and
multimeter, it was the same as any of the other cylinders...clogged? leaking? spraying too much fuel to fire? i don't know...

 

fuel injector.

burnt valve would show low compression.

usually better to start your own thread.

 

Also my charcol cans are not hooked up. I dont want them hooked up and never have had them hooked up.

Yea heck why would you want something that helps keep it from polluting the world we live in and at the same time makes the truck safer for you and your family to ride in. Something that offers functions like that and at the same time does nothing to diminish the performance of the vehicle one little bit, noooo wouldn't want that.

 

i feel a coming on.

 

You have been told the problem several times. And you ignored the advice. I have had 3 trucks that have done exactly as you described. All 3 times it was the fuel pressure regulator. Change it out. After all the money you spent on stuff you didn't need, what's another $28?

 

Yea heck why would you want something that helps keep it from polluting the world we live in and at the same time makes the truck safer for you and your family to ride in. Something that offers functions like that and at the same time does nothing to diminish the performance of the vehicle one little bit, noooo wouldn't want that.[/quote]


WOW, really?

 

Quote:

Originally Posted by kc0rey

You have been told the problem several times. And you ignored the advice. I have had 3 trucks that have done exactly as you described. All 3 times it was the fuel pressure regulator. Change it out. After all the money you spent on stuff you didn't need, what's another $28?

Yup, pretty much fixed my problem last night changing the FPR. Truck finally starts when hot. still running a little rich. going to look at a few more things tonite. i checked the ohms on all the sensors and the only ones in question are EGR valve and Coolant temp sensor.

 

This post is from the guy (kart18) that started this post - just so no one confuses me with the other guys that are posting problems here.

I checked the fuel pressure last night and here is what I got -

42 with the vacuum hooked to the FPR
37 without the vacuum hooked to the FPR
The pressure held or went up a little when the truck was shut off.

 

how could we possibly confuse who you are? ;-)