1990 F150 5.0 rough starting HELP

My 1990 F150 4x4 5.0 has started the annoying habit of being difficult to start and when it does, I need to babysit it until it warms up for about 5 minutes or it will die. It sounds like a fouled spark plug and the engine gets smoother after a minute or so of running at high manual idle. I replaced the plugs and checked the wires/cap/roter for usual signs of wierdness but it all looks good. I was expecting one of the old plugs to look fouled or a bit darker than the rest, but they all looked good. Maybe a tad on the lean side (very clean/white electrodes and no scaling or oil residue). No check engine light. (Where IS the plug to pull the codes on this truck?)

Now what? Injector leaking down after sitting for > 1 hour maybe?? How can I test the injectors? What is the average cost of a new one? Besides de-pressuring the fuel rail, what other precautions are there?

It really sucks because I cannot use my remote starter anymore!

Thanks!

-Dje

Reply to
DE
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Is there anything on the truck that adjusts for cold starting, maybe an emissions control or computer? Does it happen during start with the engine warmed up? If you had a carburetor I would think possibly an automatic choke.

How long have you had the remote starter?

Clark

Reply to
Clark

Your diagnostic port is on the left fender in the engine compartment. Go here for instruction on how to pull codes and decoding

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It is not likely that one injector could give you the problem you describe. It is more likely a bad or dirty throttle body and/or IAC. The TPS would also be suspect. Your engine is equipped with an engine temp sensor for the ECM located in the tube from the front of the intake to the throttle body. They usually fail to produce a rich or flooding condition. You need to start by getting everything cleaned up and checking the codes. Be sure to reset the ECM either with a scanner or by disconnecting the negative battery cable for 10 minutes or so. When you restart the engine, do not touch anything other than the ignition switch. Allow it to idle for a few minutes while it warms up. After that place the trans selector in each position from nuetral several times to allow it to relearn it's idle paramaters. After driving a few miles, it should have relearned the engine's parameters. Also, the fuel pressure regulators of that vintage are a bit problematic. They may leak into the intake after stopping the engine which will makes it rich for a time after it sits and restarts. You may find fuel in the vacuum line which is a sure indicater.

Reply to
lugnut

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