I have this problem with my engine 90 13b engine. When i turn it over it runs rich. When it warms up it will run loops. The rpms goes from 800 to 1500, back to 800 then to 1500, so on and so on. Now i thought it could be a vac leak so i replaced all the gaskets and checked and replaced the hoses. It made no difference i later took the reading of the fuel pressure and it was at an alarming 10psi high at idle. According to haynes manual for a 1989 to 91 engine should have a fuel pressure of 21psi. Mine was running at 32psi. ofcoarse it loop going from 32 to 35 psi with the rpm looping. This would certainly explain the engine being rich and engine flooding also. But could this be causing my engine to run loops. Idk hit me back. id love to hear some advice. thanks

 

AdjusCheck/Adjust your TPS man. then set your idle speed. Should be gravy then. Try it, or if you did, let us know so we can help you further ;P

 

yea i forgot to add that i already adjusted the tps in perfect range. I used that 2 led hook up thing. i also checked it by a multi-meter all in specific range from the book. I did also find out actully 32 psi is actully in specific range... its not that high. So im stuck at the same problem. I know that if i unplug the tps it stops the stupid looping but idles high. aroudn 3k.

 

Try adjusting thermo wax adjustment screw when its looping.

 

i tightened the screw about 3 half turns clockwise. I could only reach it when i took the throttle body off. I turned over the engine and runs much better then it did but still had a loop. It has now a higher idle at 1300 but the looping has dropped to like 100 or 200. thus loops from 1300 to 1500.

 

Yea we had to adjust while the engine was running with the intercooler off. It wasnt much to adjust .

 

I have to add. That my engine is a non-turbo. I could reach it but i just cant see it. However i also notice something on my engine that is missing. There is bracket that is missing which appears to be hooked to a ground wire. Its odd enough to know what would need to be grounded on the throttle body if the only sensor is the tps. i dont know. i will ground that see how things turn out. thanks for ur time though.