Mechanics

F350 WON'T START

1991 Ford F-350

Computer problem
1991 Ford F350 V8 Two Wheel Drive Automatic 230000 miles

Check engine light does not come on when you turn the key on. Engine won't start. Gas is there and spark is there. Engine started to miss while driving. Stopped and engine started to run rougher and then it just stopped. Cranks good but will not start.
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Dragonstormer
November 29, 2008.



This is a canned question, but I have to ask, ECM and other fuses good? According to your posting, you have fuel pressure and spark. Assuming this is correct, do you have injector pulse? With no check engine light at " key on" and no injector pulse, I would have to say your computer died. Please advise.

Tiny
James W.
Nov 29, 2008.
I took a test light and grounded it. The injector plugs going into the injectors both sides had power. I checked a couple of them all the same.

Tiny
Dragonstormer
Nov 30, 2008.
Testing both sides of the injector plug while cranking, do you get a pulse from either side? If no, I would change the crankshaft position sensor. Let me know.

Tiny
James W.
Nov 30, 2008.
Hi, I got a pulse on one side. Hooked test light to Positive post on battery.

Tiny
Dragonstormer
Dec 2, 2008.
The computer grounds the injector to fire it. Your teast from the positive battery is correct. But, we are missing something. If you have injector pulse, fuel pressure and spark, it should run or at least try. I would re-check spark at the plugs and fuel pressure at the fuel rail. Let me know.

Tiny
James W.
Dec 2, 2008.
Hi, I have 40 lbs fuel pressure and I still have spark. Thanks

Tiny
Dragonstormer
Dec 11, 2008.
Hi, I have 40 lbs fuel pressure and I still have spark. Thanks

Tiny
Dragonstormer
Dec 13, 2008.
I hadn't forgotten you, I had some computer problems for a while.
We're missing something here. Are your plugs wet from repeated start attemps?
Pull the vacuum line off the fuel pressure regulator and see if you have raw fuel in the line. If the diaphram in the FPR has popped, it will send raw fuel into the manifold and flood the motor. Please advise.

Tiny
James W.
Dec 13, 2008.
Hi, I tried that no fuel. Spark plugs dry. I tried starting with ether won't start. Have spark at distributor cap but wasn't getting any spark through wire to spark plug. Replaced wires still won't start. Any idea.

Tiny
Dragonstormer
Dec 25, 2008.
Hi, I was getting a spark at distributor cap but not down to the plugs. Plugs are dry. I was not getting a spark through to the spark plugs. I replaced all ignition wires. Still won't start. I checked primary and secondary parts of the coil. Came up within ranges. Went and bought another coil and checked it. Came up with the same readings as the old coil. Replaced coil anyway. It runs now. Yet according to the readings I got the old coil is the same as the new one. Only thing I can think of is it fails when you put a load on it. So if I hadn't replaced it I still would be in the dark. Thanks

Tiny
Dragonstormer
Dec 26, 2008.