Ok so i have had an issue with this motor for a while. I have changed everything from fuel injectors to the regulator and filter. I have checked all the vacuum lines with no leaks, the coil and wires are new as well as plugs, new O2 sensor, checked timing, tested MAP sensor and fuel pressure is around 60 psi while at idle. no Cats as they were stopped up dual pipes running to a thrush dual in/out muffler 2.5 pipe. EGR is not connected. Before we played with the timing it wouldn't start without help from ether and would stumble on idle and just flat out refuse to run without playing with the throttle, but it would cruise fine but would hate going 30 or below it would just start bucking. After we played with the timing it will start and idle better but it misses now cruising with it set around 5-7 BTDC. The engine has around 16000 Miles and was put in in Jan 2010 and it has always burned rich. The ECU died on me about 2 years ago when moisture got into it and the 10MHz crystal rotted off and i repaired it and the truck ran good. We can't figure out where to go from here and i have a trip to Michigan from Tennessee In the 3rd week of April, so if i can get any help it would be greatly appreciated.

Thanks in advance
Chris Braun

Oh, I don't know if this will make any difference, but i'm running a K&N air filter in the air box.

 

I couldn't get it started this morning it just cranks over until I spray ether into it then it'll start and "try" to run

 

60 PSI of fuel pressure is too high with the engine at idle. ~45 is more typical. I do not see any mention of codes. Did you run the Key On Engine Off (KOEO) tests and stored code display?

Only starting with a shot of fuel or ether leads one to think it's a TPS, ECT or ACT issue. Suggest you checked their values.

 

Im not sure if the check engine light works. I've checked the bulb but I have never seen it turn on or flash or anything

 

The Check Engine Light should turn on momentarily when you turn the key to the Run position.

 

I get nothing. I have a red engine light that works but I also have a yellow check engine spot on the panel with a good bulb in it

 

Then you have a problem. Could be bad wiring/connection or a bad computer.

 

When my 93 4.9 would crank but not turn over it was the ecm hat was bad. Two capacitors were leaking, one was completely broken off. Before that it was the tank selector that was broke. Both of these had my truck cranking but would never turn over. Would start when I sprayed carb cleaner In the intake. Then die shortly there after