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40,000 ORIGINAL miles.
Turns over like a champ, but will not start.
Fuel Pressure at the rail > 40 psi
I have replaced: coil, wires, plugs, rotor, cap, distributor (with new TFI module)
I have spark from coil to distributor.
This is not a duraspark. It will not start cold. (cold= less than 80F ambient temp.)
The deflection on the timing chain is negligible (I think) How do I know that? I rotated the crank until the rotor started to move and then reversed direction and the rotor moved immediately.
When I replaced the distributor, I was off by one tooth–it would not crank. I removed and retarded by one tooth and it fired right up. For more than two hours, this thing went through at least thirty start cycles and was reliable as ever.
As soon as it went cold (really cold-next morning) it would not start. I didn’t mind replacing all of the secondary ignition components, as it was due for that amount of love after 20+ years, but I am mystified. I need some direction at this point. The only time that I’ve been able to get it going is in the afternoon (ambient temp> 70F) and it is “nervous” at best. I have advanced and retarded while cold and it will not respond. In the afternoon, this baby wants to run!
Coolant Temp Sensor? I don’t know. I’m lost at this point. Any knowledge you have would be greatly appreciated.
PS. it will throw a CEL, but I don’t know how to pull those codes on this engine. I don’t have a machine that will talk to a Ford ca. 1991, I’m a shadetree, at best.
**Update**
It was the fuel pump. I was thrown off by the fuel pressure being good at the rail. I replaced the fuel pump yesterday and she came back to life! Kudos to Eric and his suggestion of fuel delivery. Thanks to all for your help. It was the first really humid day here in Alabama yesterday, so that made for a particularly sweaty job. Sadly, it is only going to get worse. Thanks again, I love this site!
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if you have spark from the coil to the distributor. check to see if the rotor is touching the
inside of the cap button.Hi davispb,
Here are some links that might help with determining what the CEL (check engine light) is. Good luck and keep us posted.
For a list of codes for the ’91 truck:http://www.fordf150.net/howto/eecivcodes.php
How to read the codes without a scan tool (youtube):
http://www.youtube.com/watch?feature=player_detailpage&v=OBqJfjDTlFkQuoted From college man:
if you have spark from the coil to the distributor. check to see if the rotor is touching the
inside of the cap button.New cap, new rotor, I understand your concern,I’ll check it again. I didn’t put a computer on it, but it is firing at all 8, otherwise it wouldn’t have fired so smoothly yesterday afternoon.
Could there be a water bubble in the tank that doesn’t move from one side to the other until I punch the block in the face? ‘Cause it’s only fired after I’ve gotten so angry that put 4 knuckles to its face.
How are you check for spark from the coil?
Did you try using a test light on the negative side of the coil to check your triggering device?
This is a wierd one. I have a ’91 F-150 with the 5.0 engine. One day, it wouldn’t start in a parking lot at Home Depot. Nothing was working. I eventually out of frustration began to swap the front/rear tank switch back and forth a few times, and it fired right up. When it won’t start, can you hear the fuel pump run when you put the key to the run position? If not, try switching the switch. I know this isn’t technical, but it’s based on my experience. I normally only use the front tank, because I can’t even begin to afford filling one tank, much less both. Just something random to try.
Well first we need to set base timing and leave it there, you adjusting the timing to get it to start may actually end up damaging the engine so perform the procedure to get base timing and leave it there. If you know you have spark and after you set the timing that should also be correct, and it still doesn’t start we need to start looking at the fuel delivery and idle systems. I think you mentioned somewhere you had a CEL and someone posted how to pull those codes so perhaps set the base timing and pull the code and we can take it from there.
Quoted From college man:
Thanks for the update and the fix. what gave it
away that it was the fuel pump?Fuel pump wouldn’t turn off. I thought that it might be the fuel pressure regulator and started there, as it was cheaper. When that didn’t work, I moved on to the fuel pump and that did the trick. Side note: I didn’t have a 15mm deep well socket, so I had to remove the tank straps with wrenches. The straps were also not held with captured bolts, so it took two wrenches, a 13mm on the bolt and a 15mm on the nut. The access to the top of the bolt was really tight due to a driveshaft shield, so it also hurt quite a bit with my arm between that shield and the tank. I was bitching. Also, when I turned the key to on after pump replacement, the fuel guage needle pegged. I took a rubber hammer and banged on the tank where the float should have been and watched the needle come back to normal range. When I installed the pump, I must have caught the float against the side of the tank, causing the needle peg. Once again, the “hammer adjustment” did the trick! Sorry for the length.
Quoted From davispb:
Fuel pump wouldn’t turn off. I thought that it might be the fuel pressure regulator and started there, as it was cheaper. When that didn’t work, I moved on to the fuel pump and that did the trick. Side note: I didn’t have a 15mm deep well socket, so I had to remove the tank straps with wrenches. The straps were also not held with captured bolts, so it took two wrenches, a 13mm on the bolt and a 15mm on the nut. The access to the top of the bolt was really tight due to a driveshaft shield, so it also hurt quite a bit with my arm between that shield and the tank. I was bitching. Also, when I turned the key to on after pump replacement, the fuel guage needle pegged. I took a rubber hammer and banged on the tank where the float should have been and watched the needle come back to normal range. When I installed the pump, I must have caught the float against the side of the tank, causing the needle peg. Once again, the “hammer adjustment” did the trick! Sorry for the length.
I hope you cleaned the tank out real good before you installed the new pump. If not you may be doing the job again.
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