5.8l constantly running rough
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thanks for the idea bob. anyhoo i sprayed the livin sh8t out of the areas that you mentioned and then finished the can off on everything else (ready to pass out). another troubleshoot technique...i listen to a lot of am radio and "normally" you know when there is a ground or arc going on. hell it even picks up electric fences when i pass by one. im only getting the normal static. i think i can rule out a few things, but i still need to test fuel pressure and then compression. this motors innerds have got to be about like new. it has been very well kept up inside. anyone know how to check for a plugged or faulty injector or what the voltage should be at the injectors? im lacking in that area. i was just thinking, my last motor was a 6.0l ps. (i know what the ps is for) but this issue is beginning to take me back to those days
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Joined: Aug 2001
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From: Lexington Park, MD
Did this truck ever sit for a long period with gas in the tanks? You mentioned that the fuel filter was very old.
I definitely agree with you about getting your hands on a fuel pressure gauge. That would answer many questions about the performance of the pumps and the fuel pressure regulator.
You might try pulling the vacuum line off of the fuel pressure regulator. If it's having problems you might have some fuel coming out of the vacuum nipple.
Sorry but I dont have injector resistance values for a 96. Just a 91. Yours being sequential fuel injection they are probably different. Best of luck!
Chris
I definitely agree with you about getting your hands on a fuel pressure gauge. That would answer many questions about the performance of the pumps and the fuel pressure regulator.
You might try pulling the vacuum line off of the fuel pressure regulator. If it's having problems you might have some fuel coming out of the vacuum nipple.
Sorry but I dont have injector resistance values for a 96. Just a 91. Yours being sequential fuel injection they are probably different. Best of luck!
Chris
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From: Kentucky
Spray all you want, but more than likely you will have same the same results....inconclusive. There are several vacuum reservoirs in the engine compartment that frequently get overlooked. Typically if a vacuum reservoir is leaking you will get a high idle as well as a possible Lean code.
The injectors are always fed with battery voltage whenever the key is in the Start/Run position. The PCM controls when/which injector to fire by "grounding" the proper injector(s) at the right time.
The injectors are always fed with battery voltage whenever the key is in the Start/Run position. The PCM controls when/which injector to fire by "grounding" the proper injector(s) at the right time.
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Update: did compression test #2 thru #8 cylinders between 151 lbs and 155lbs. No. 1 cylinder tested (twice) 174 lbs. I dont know alot but isnt that more that straight off the line? Meanwhile, when i was doing the test, no. 3 cylinder spark plug was very wet. still investigating
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another update, a couple of nights ago i did "the old wait til its really dark and watch for arcing." I had arcing on each side of the coil, one from each plug to the manifold, and one between the belt and the idler wheel...cool.
the obvious thing was to replace the coil, done. i replaced all of the plugs again with motorcrafts. i did pay a bunch for the wires and i aint doin it again. runs the same. lately i have had a hunch with #3 cylinder so tonight i pulled that plug and what is on the end of it looks exactly like the gum that you find in a carburator that hasnt ran in five years. Is that injector sticking? well ill find out tomorrow. if the injuctors are always powered and are activated by grounding, i may have found the culprit. the only way i can see it is with a camera, but by feeling the wires it seems the yellow wire was stuck to the bottom of the plentum, hence grounding it which would cause a continuous spray, i hope. chapter 9 tomorrow
the obvious thing was to replace the coil, done. i replaced all of the plugs again with motorcrafts. i did pay a bunch for the wires and i aint doin it again. runs the same. lately i have had a hunch with #3 cylinder so tonight i pulled that plug and what is on the end of it looks exactly like the gum that you find in a carburator that hasnt ran in five years. Is that injector sticking? well ill find out tomorrow. if the injuctors are always powered and are activated by grounding, i may have found the culprit. the only way i can see it is with a camera, but by feeling the wires it seems the yellow wire was stuck to the bottom of the plentum, hence grounding it which would cause a continuous spray, i hope. chapter 9 tomorrow
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well, i found the problem. it seems that a mouse chewed the white #3 injector wire in half. i took pics under the plentum but couldnt see the bad wire until i removed the plentum. thanks for all the knowledge and ideas guys. this site has saved me thousands in the past.
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I was going to say you should clean out your egr system since you got that code, might not be a bad idea anyway. Stupid mice... Glad you got it figured out!
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I had an ornery squirrel chew through the VSS wiring on one of my 1993 Lightnings. Two days later the sucker tore up the wiring from the front fuel tank.
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Bob
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