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ECU Diagnostic Codes? Rich, No Power

1614 Views 8 Replies 6 Participants Last post by  88pathoffroad
Hello guys, another long read for you. Maybe you can help me out.

I have an 86.5 Hardbody with the 3.0 V6 with TBI. My truck has been running very rich since I bought it about a year and a half ago. It has no power whatsoever after 2nd gear, and takes forever to reach highway speeds. It will do the speed limit on the interstate and then some but I'm lucky if I can get to 45mph before the merge lane ends. Once I get up to speed it will do 80+ all day long.

It used to burn a small amount of oil, I pulled the heads about 7-8 months ago and replaced just about everything but the valves. The new valve stem seals solved the burning oil issue but I still have no top end power. I checked the compression on each cylinder a few weeks ago. It was the first time I had ever done a compression check so I followed the instructions in the tester package.

I pulled all the plugs and tested each cylinder buy cranking the engine 5 rotations per cylinder. The lowest reading was 130PSI and the Highest was 140PSI. The Haynes manual reads that the specs for cylinder pressure at 300rpm is 173PSI, 128psi minimum, with maximum difference between cylinders 14psi.

I also tinkered with the MAF about a week ago buy cleaning it with alcohol and q-tips. Since I cleaned the MAF the truck has died on me several times and drinks fuel like no tomorrow. It drank fuel before I cleaned it but it never died on me before, not once.

Sooo.. Long story short, I tried to see what the ECU would tell me and it told me jack shit. I got 3 red flashes 1 green flash, Code 31 which reads in the Haynes as "The ECU input signal is beyond "normal" range This repair must be performed by a dealership service department."

I also got 2 red flashes and 4 green flashes, which would be Code 24. My only issue with that one is that it isn't listed in the Haynes. So I have no clue what it means.

I checked the ECU as instructed in the Haynes, that doesn't mean a whole lot so If you think I might have missed something please let me know.

Ok I feel like a real dope now. I just now realized that the ECU sticky applies to my 86.5 too. I didn't wait for the 3 flashes to enter Diagnostic mode... Will try again tomorrow and get you guys the real codes.. Sorry
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turn the key to the on position but not running.

the lights will flash, turn the switch on soon as it flashes three times turn it off and the record the flashes...

the 3 flashes put it in diagnose mode...
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