Hey there, I am at the end of my chain trying to get this darn thing to run. The truck just wouldn't start one day and it has been nothing but tears since. I started of doing a regular tune up, I figured that maybe it had just been too long since the thing had gotten any love, so new cap/rotor plugs wires, checked the air filter, looked fine, still wouldn't start. it was doing a wierd thing where it would crank over for most of a turn, then halt, then crank, then halt. figured it was battery/starter, so replaced both, and the same thing happened. on a hunch I got out my timing light and tried that (remembered to remove the spout wire to check the timing), and it turned out that the engine was firing way early for no good reason (like 20 degrees) so that when a cyl tried to fire during starting, it would stop the engine from turning. unbolted/adjusted the distributor and finally got it to start, but it was darn rough. it would only start under wide open throttle, and runs like junk for the first 30 seconds or so, then it seems to 'pick up the other cylinders' and smooth out a bit. the truck is a 92 f150 that I got off a kid about a year ago, and it had recieved *no* regular maintainance of any kind, I can almost entirely garuntee you, so I decided to go all out, I replaced the ICM and the coil, and the fuel filter. I thougth it might be a fuel pressure issue but the pump puts it up to 70 psi with KOEO and keeps it at 45 PSI in KOER, both within spec (at least as far as the Hyanes manual says). I ran the ECM tests and got an engine coolant tremperature sensor out of range error in the KOEO test, and an 'always lean single O2 sensor, did not switch over' error for the KOER test. the Engine coolant sensor tests out fine, and I replaced the O2 sensor. Someone also suggested that the bad O2 sensor may have led to a plugged cat, so I took it off. after replacing the O2 sensor and removing the cat I blanked the ECM again, and had the same problem. The truck won't start unless it is in wide open throttle, takes a second to pick up and run semi normally, and it also has a hesitation problem, if you just tap the gas pedal it will nearly stall the engine and the only way to get it going is to press the accelerator very very slowly. I also put some injector cleaner in it and drove it around for a bit, and it didn't seem to make any difference, but while I was doing it I noticed something very alarming, when the engine is at Idle the oil pressure drpos through the floor, and you have to rev it up quite a bit to make it come up. it had an oil change not too long ago, and I cheked the oil and it is still between the marks. I am really at the end of my rope here, do any of you guys have any suggestions?

 

oil pump might be bad iff pressure is non exsistant, also maybe its just the computer. i dont know. my 2 cents...

 

Could be map sensor or tps or broken wirering to one of these items, I find it funny that the distributor was out 20 degrees, had the kid been working on it and screwed something up. The best lesson I ever learned for fixing anything is always start at the beginning and don't jump any steps and 9 times out of 10 it will be something simple like a broken wirer or something installed improperly. Also how old is the gas and did the engine ever run right when you got it?

 

It has been running great for the last year or so, gas in it is only about 3 weeks old now (was fresh before it started not starting). I haven't manualy tested the tps, but it is covered by the KOER test. Dunno about it just being the oil pump, but then again, something is wrong with it.

 

Two things come to mind when you state the timing was off that far.

1. Timing gears could be bad, and jumped a tooth.

2. Distributor gear. The roll pin on my 85 300-I6 Bronco sheared. Most of the pin stayed in, retaining the gear,but allowed the gear to twist slightly. Truck would run, but very badly. Gear fell off as I removed the distributor, falling into the oil pan. I replaced the distributor and all was fine.

Could the oil pressure issue be due to the engine idling at such a low RPM that it isn't able to build pressure? And is the pressure gage a real gage, or one of Ford's brilliant idea idiot gages?

 

Could be something as stupid as the battary cables, I had a voltage loss and that caused timming problems and all other stupid stuff that you discriped. I would change them out, it's a lot cheeper then what you have done so far.

Chris

 

laff @ fords idiot gauges...

 

Did you check the timing with the SPOUT connector removed? If not, your timing will be about 20 degrees BTDC at idle.
I would check for vacuum leaks, particularly the throttle body to intake gasket.
Also remove the vacuum hose to the fuel pressure regulator and check for gas in there. There shouldn't be any.

 

I did remove the SPOUT wire to check the timing. I already took off the timing cover to check the timing and it appears to be right on (dot to dot right?) I also replaced the negative cable on the battery (ground nice shiny spots to connect it to and everything) and the positive cable is in really nice shape.That is an interesting idea witht he sheared rollpin on the distributor and I will check the vacum line to the regulator. Is 45psi really all the fuel pressure that it needs to run?

Oh Yeah, and it is a gauge, not a light. in idle it just drops down to nothing, something is wrong there. The oil pump runs off of the camshaft right?

 

1. Timing gears could be bad, and jumped a tooth.

2. Distributor gear. The roll pin on my 85 300-I6 Bronco sheared. Most of the pin stayed in, retaining the gear,but allowed the gear to twist slightly. Truck would run, but very badly. Gear fell off as I removed the distributor, falling into the oil pan. I replaced the distributor and all was fine.

Could the oil pressure issue be due to the engine idling at such a low RPM that it isn't able to build pressure? And is the pressure gage a real gage, or one of Ford's brilliant idea idiot gages?>>>>

I concur with these guesses for now. A sheared distributor pin will sure cause what you are describing...It's a timing problem I think...MK

 

Nope, Not a dummy light, gauges. Checked the timing gears and they were right on, but I didn't actually pull them to check for a sheared pin. As far as the oil pressure goes it isn't a dummy light it is a gauge, and it isn't just not sufficuent pressure at idle, it is no pressure at all, and after the truck gets going it idles ok, so I think that you guys are right on with the sheared pin on the distibutor assembly, I am not too familiar with the insides of the I6 but I think that it is a safe assumption that the oil pump runs off of the distributor shaft. I might try to take it off tonight and see what is going on. I thought it was odd for the timing to suddenly be off like that.

 

Nothing seems to work, this stinks. We cut off the second cat (the y-pipe one(no change)) We added an extra ground wire to the engine, straight from two points on the engine to the negative terminal on the battery(no change) and we removed and inspected the distributor assembly. There was some apparent metal dust on the metal plate under the rotor that appeared to be contacting the sensor, so we cleaned that out completely, but the gear was still perfectly intact, and you could see straight through the roll pin. The truck has seemed to be starting a little bit better now, so maybe it was dirty injectors, I did only drive it for about 6 miles after I put the cleaner in, so maybe I'll just run dual exhaust all the way to the back and drive it around for a while and see how things go. The KOEO test still gives a 118, ECT high/out of range, and the KOER test only gives a 118,998. Still though, my ECT seems to be working.... maybe an indication of a wierd bad ground somewhere? I'm going to just drive it for a while and see if it clears up.

 

Make sure the EGR valve is not stuck open. With the engine running, insert a small flat screwdriver into the little hole on the engine side of the EGR valve. You will feel it when it contacts the rod in the center. Make sure you are not pushing on the diaphragm, and push the valve open. The truck should idle very rough, or maybe even die.

Also, these engines are notorious for sucking the throttle body gasket apart. Take off the four nuts and replace the gasket. It is a very quick and easy job.

 

It just started running rough after I adjusted the timing, just noticed today after working on it for a week that the crankshaft pulley had a wobble. Turns out the harmonic balancer has slipped out of balance. This causes a multitude of problems including rough idle and inability to time properly. I will let you know if it solves my problem.