IDEAS NEEDED COULD MY THEORY BE CORRECT??
 

Hello all-

This is my dilemma- I have a 1990 F350 Crewcab 4x4 truck 351W C6 trans. emissions have been removed, truck runs with no codes thrown by the ecm. I have replaced starter with a good new unit, not replaced, solenoid has been replaced with a motorcraft unit, distributor has been removed and new pickup coil has been replaced. ignition control module has been replaced, and has been remote mounted to the fender of the truck to keep from being baked by engine heat like when mounted to the distributor. Truck has a Holley annihilator ignition system with a quickshot power programmer. I have cleaned the IAC valve and the entire intake. the alternator has been replaced alone with the coolant temp sensor, intake air temperature sensor, plugs, wires, cap and rotor have been replaced. The egr valve position sensor wire has a dummy resistor plugged into it to fool the computer. the truck has almost 120,000 miles on it. Lately I have been trying to diagnose a hot start problem. whenever the truck goes about 10 miles and you shut it down, it doesn't want to start when it is hot. When I crank the engine over, it cranks very very slowly like the battery is discharged, the battery is good. I never have the problem when the truck is cold, it starts right up. All wires to the solenoid and the starter have been replaced, the battery ground wire has been replaced and new ground wires have been run to both sides of the engine. After doing all of this i thought that maybe the starter was getting heat soaked and put a heat shield on the starter, no change. I have found that the only thing that corrects this problem is when I Use the quick shot programmer to RETARD THE TIMING BY 20 DEGREES! 4/ 8/ and 10 degrees will not get the engine to fire. I am wondering if by putting the resistor in at the EGR VALVE and bypassing it, the computer is monkeying with the timing and advancing the timing because the egr valve isn't supplying the engine with the inert exhaust gas back into the intake to be burned to lean out the fuel mixture. The computer ends up leaving the timing way too far advanced when you try to start it when its hot, when its cold it goes back to cold start mode. IDEAS are welcome. I figure I'm right, or the timing chain is stretching out way too far when hot. Please let me know what you think.

have you checked the timeing with a light? it is too far advanced, and will act just like that, my guess is it should be about 8*, and you have it sitting about 30*. best change it before you blow up your starter, or burn a hole in the top of one of your pistons

another thought, if it won't start where it should be at tdc, your dist is a tooth or 2 off, and needs to be put back into spec.

The initial timing was set at 10 degrees btdc. I checked the mark i made on the distributor body, it is still at the same place. The distributor hold down is secure. I don't think it moved. But I will check the timing. I don't think that is it, because here again, i don't have a problem starting when it is cold. I only have a problem starting when the vehicle has gone over 10 miles is shut down and i immediately have to start it again. the distributors in this truck have no vacuum or mechanical advance because it is controlled by the computer and the computer alone.

I have the very same problem,If i wait 1 min it will restart and run normal,start normal, seems after i drive in slow traffic then shut it off it does this. My guess is one of 2 things on my truck,and those are, 1st pip in dist.,2 vapor lock, My headers run fairly close to the fuel filter and think that probably has a lil bit to do with it. Could be a failing ign module also

This could be a rich mixture problem, what is fuel consumption like? Do you have a wideband O2 sensor? My 5.8 was doing this just before I took it out and I have since found out the computer was dying and putting too much fuel into the motor.. which washes the oil off the cylinder walls and makes hot restarts difficult.

fuel consumption has usually been around 10-12 mpg with this truck, it has a 4.10 rear gear, so i figured that was probably something to do with it. Also I figured it would be running rich because of the disabled egr valve, it has a resister plugged into the electrical connector, i don't have a wide band o2 sensor. But I do have a spare remanufactured computer laying around from oreilly's on the shelf that i could plug in and run it to see if it does this again.

The EGR eliminator won't make it run rich, the computer really only adds a little more timing when the valve is open and since the plug tells the computer it's closed that won't happen. 10-12 mpg sounds about right considering it's a 7000lb truck with lots of gears and no overdrive. Are you removing the spout plug to set the base timing? Is your programmer making the engine run open loop all the time or otherwise adding fuel?

my truck did this. started up cold always. after it got hot it turned over real slow. and sometimes not at all. battery checked out good but was told to try a bigger battery. went from 650 cca to a 850 cca, and havent had problem since. atleast now i know i have a new battery. try that maybe.
1996 f250, crew cab, 460, e40d, 4x4

So-Cal Sancho- the battery that is in the truck already has 850 cca, the battery isn't the issue.

Conanski- haven't had time to re-check timing yet, when i set the base timing b4 i did remove the spout plug. The annhilator I wouldn't think would affect the computer it's a capacitive discharge ignition system, and it doesn't control the advance curve, its sole purpose is to give multiple sparks below 3000 rpm, then gives you a single powerful spark above 3000 rpm, It doesn't do anything to the fuel curve.

its vapor lock... kinda

the fual rail placement is kinda bad as when ya shut off the engine the heat gets "sucked in" to the fuel rail ( made of aluminum) and expands the more volatile winter gas that when ya go to crank the injectors end up shooting to much gas in the camber causing to much compression,

solution
when ya go to start the truck back up... pop the hood take a knife Phillips what ever you have and depress the zerk fitting on the fuel rail and crank her up
or..... just wait till she cools down

long term... wrap your fuel rail in some sort of heat shield something for like headers probably or... get longer injectors so that your rail is further way from the valley

just my .02 as my truck does the same thing look at it this way atleast ya know ya got killer compression:-X06

Okay, I had time to work on it today, the initial timing was at 14btdc, I changed it to 10btdc and ran the truck 10 miles each time i changed the timing. nothing helped the hot start issue, until I changed the computer. Conanski gets credit for that one. Not only that i started to bump the retard upon startup feature on the annhilator, with the old computer no change in the crankiong speed, with the new computer, it changes the cranking speed!! It had nothing to do with vapor lock, I didn't figure it would with fuel under 38 psi of pressure. However, I did note that with the new computer it has shown two new codes that the old computer didn't register, a code 33 and a code 41. code 33 has to do with the egr valve not opening, probably the egr eliminator, code 41 is the oxygen sensor always reading lean. Any ideas??

okay, after doing some reading, the code 33 is what i should be getting with the egr eliminatoe, so that one I could care less about. The code 41 usually means I could have a vacuum leak or a contaminated o2 sensor. Thanks to everyone for their ideas with this one. Its funny, the old computer wasn't throwing any codes, and was definately on its way out. But at least I get to drive my truck and not be scared whether its going to start again when I shut it off. Thank You Guys!!

Running the way it was before might have screwed up the o2. In my experience they are pretty sensitive and can go south easily. I've had poor running conditions for only a couple of days and it's been enough to cook the sensor.