This thing has a problem with running very rich - not to the point where it generates a black cloud of unburnt fuel, but you can definitely smell it. Here are the symptoms:
Hard to start - must depress throttle slightly (thus allowing more air in) to get it to start more easily. I say more, because it takes at least three or four tries of 3-5 seconds to get it started - or more.
After started, raw gas smell evidenced from exhaust. Idles at ~1500 or so, but drops down to 5-600 within 3 minutes. After running for about 5-7 minutes, idle will start oscillating between 5/600 and 200 or so and will eventually die unless a little extra throttle is applied. Even if throttle is depressed and engine allowed to run until it reaches normal operating temperature, it still smells like its running rich.
I haven't pulled codes yet, but I was wondering if there is a common failure point for EEC-IV on these engines. I'm also wondering if anyone has a map to the sensors and the test procedures for them; I am very familiar with the "classic" Bosch injection systems from D-Jet to Motronic and this is new territory for me. It's not immediately obvious where they hid all the sensors on this engine.
I'd also like to comment that none of the manuals I've collected for the truck to date have ANY useful info on this matter except for a list of how to pull and interpret codes. No sensor locations, no test procedures, nothing. Thanks a lot, Chiltons.
Im having a similar problem but my truck has the black cloud of smoke choking anyone within a 100ft radius lol. I have the Haynes manual for my truck an 86 F150 with the 302 EFI and it has been helpful some what. I still have the smoke out of the tail pipe but it has the information you are looking for..
This thing has a problem with running very rich - not to the point where it generates a black cloud of unburnt fuel, but you can definitely smell it. Here are the symptoms:
Hard to start - must depress throttle slightly (thus allowing more air in) to get it to start more easily. I say more, because it takes at least three or four tries of 3-5 seconds to get it started - or more.
I'd also like to comment that none of the manuals I've collected for the truck to date have ANY useful info on this matter except for a list of how to pull and interpret codes. No sensor locations, no test procedures, nothing. Thanks a lot, Chiltons.
that is common to not give sensor locations. My haynes manual seems to give more info on that. I have both- each of the manual have good info in them.
First thing I would do is pull the vacuum hose off of the fuel regulator and check to see if there is gas in it. That is the first common problem to a super-rich condition. The diaphram breaks in the regulator and dumps fuel into the intake through the vacuum hose.
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'00 in the drive, '85 F250 that runs, '84 F150 in the weeds, minus 1 '85 F150- I finally got rid of some junk..
