TommieGage

My truck is a 94 f150, the other day it would not start... I drove it to work that morning, it was acting a little strange, it backfired once, and then bogged down, the the rpms shot way up, then back down to normal. It will crank, just will not catch and turn over. I replaced the ignition coil, but still no turn over... Any help with a diagnosis would be helpful... Thank you in advance for any assistance!!!!��

Steve83

"Turning over" usually means "cranking" - what the starter does to the engine, making it spin. Yours seems to be turning over, but not "running" or even attempting to run. Stop replacing parts without diagnosis. I'd put the original coil back on, since it's apparently NOT the problem, and is likely higher-quality than any replacement. Try NOT to disturb any wiring, vacuum lines, or other parts since you might hide the problem.

Measure fuel pressure with a gauge, as shown here:


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Read the fault codes with a jumper wire:


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Follow the ignition diagnostic procedure in this caption:


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If you don't have a Haynes manual yet, now's the time to get one, but read this caption first:


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When you have it, READ IT. The Troubleshooting section before Ch.1 right now, but read the whole thing cover-to-cover so you know what's in it, where to look for it, and how to use the manual.