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sbizkit38 · Mar 26, 2011, 09:21 PM

Ok, I have a problem that has been going on for at lest 2 years now, and no one can figure it out. Basically, I can start my truck at any time, day or night. In any weather, etc. Then I can drive the truck 1/4 of a mile, or 400 miles, it dose not matter. When I shut the truck off, lets say to run in the store to get a can of Copenhagen. When I go to start the truck again (right away, mind you) I can hardly keep it running. It will start like a champ, but soon as I let off the gas pedal, my RPM's bottom out and the "pig" stops running. I can be slowing down to turn at a light, and if I'm not careful it will stall on me in the turn. It's so bad that I've had people tell me "give it a tune up"! As if I haven't thought of that. I've charged the camshaft position sensor, new plugs, wires, coil, distributor cap, PVC valve, crankshaft sensor, new battery, battery cables, oxygen sensor, new fuel pump(which by default came with a new fuel sending unit and filter). I am at the end of my rope. Don't want to take it to a dealer. My wallet couldn't handle that right now. Please help.

TxGreaseMonkey · Mar 27, 2011, 05:49 AM

What engine?

I'd focus on:

. The Engine Coolant Temperature (ECT) Sensor, which affects fuel injector pulse width. The ECT Sensor is a temperature dependent resistor (thermistor), whose resistance decreases as the engine coolant temperature increases. It provides a richer mixture when cold, leaner mixture when hot. They become corroded, due to not changing the coolant frequently enough, flood the engine, and waste a tremendous amount of fuel. Do your plugs looked fuel soaked?

. Ignition system. Something is likely breaking down in the electronic ignition system; e.g. Ignition Control Module or ignition pickup coil.

sbizkit38 · Mar 30, 2011, 12:01 AM

Thanks for the response Tx. That ECT sensor sounds like it is worth looking into. I have not looked at the plugs, since I just put them in last spring. The little " trifling witch " is up on jack stands right now because of a front brake line issues. But as soon as I get done with that project, I'm going to look into that Sensor. That ECT should be in my "Bible", I mean my Haynes manual. But maybe u could give me a heads up to where it is? I did change my ignition coil not long ago.A buddie told me I should take the throttle body off, and clean it real well.Or that maybe it was an injector. I listened to them clicking, and one of them did sound a bit off, compared to the other one's, but I'm not sure. What do you think Tx? One other thing I failed to mention was I had a fuel line pressure check done, and it's right as the rain. Thanks again.

sbizkit38 · Mar 30, 2011, 12:05 AM

Oh yeah, the engine is the 3.9, 6 cylinder. 1998 2 wheel drive, extended cab.

TxGreaseMonkey · Mar 30, 2011, 07:02 AM

I don't think there's a problem with the injectors or fuel system. Instead, I suspect there's a problem with the ignition system, if replacing the ECT Sensor does not solve the problem. Look at AutoZone.com for what your ECT Sensor looks like. They always have 2-wires going to them and are often installed into the end of the engine block. Your Haynes Manual will certainly nail it for you.

Only use Champion spark plugs in your truck--the exact ones that originally came in it.