Out of ideas! Please help
 

Hey everybody I have a 1990 4Runner SR5 v6 3.0 that I just got running agian. I just put in new spark plugs and wires,new cap and rotor,new battery, and new mass air flow sensor. Before all that was replaced the truck was not starting at all. Now it starts but has a series of issues
1. No power on acceleration
2. Running extremely rich
3. Very low idle when engine is warm (400-500rpms)
4. Seems to shift gears roughly

I'd appreciate any help I can get fixing this I really need it running agian in missing the trails. :bang::bang::bang::bang::bang:

FYI this is the testing section

Your bogging issue and running rich problem may also be affected by the O2 sensor. An OBD2 tester would be a good start to eliminate it as part of the issue. I don't want to sound like a smart arss but did you test your coil output? You stated that you replaced the cap an rotor, therefore you have a separate coil for the ignition system. Quite honestly, I personally would start right there. I have a 96 3400 4cam 5vzfe engine and it has coil packs. One of the coil packs would work (ok) sometimes and really die under acceleration or pulling a hill and especially towing my trailer. I replaced the coil and it became the monster engine it used to be. I'm looking into a performance chip for it but I have mixed thoughts on them. One in particular claims 6-10 more HP and 8 MPG improvement. Why wouldn't the factory set these parameters from stock conditions? If someone happens to read this and has any thoughts on it, please drop me a line with your ideas. Best of luck with your bogging issue, hope this helps.

Another thought I just had was that my truck had aftermarket plugs ( Autolite ). My engine had a sticker right on the timing cover showing that the plugs needed to have double elements on them. The Autolite plugs were single element. That repair made a HUGE difference. May want to look into this.

This is a pretty old thread, but I will address your question.

I personally wouldn't install any sort of "performance chip". You are right. Toyota would have simply programmed their computers for more power and fuel economy and still comply with emissions regulations if it actually made a difference.

I have come to the conclusion that unless you plan on making your own engine setup from scratch, it is best to leave things as Toyota made them. I put performance chips in the same category as "cold air intakes" you often find on eBay.

On vehicles that have an electronic accelerator pedal, the "performance chips" often move up the the acceleration curve to the first half of pedal travel, giving you the feeling that performance increased because you don't have to push the throttle as far to get the same response, but it makes the other half of the pedal travel useless... but now I am just rambling.....

:safari:

Performance chips
 

I digress. Thank you for your help and advice. Saves me money and hassle down the road. I guess I was just wanting to believe that there was a miracle device out there to get better gas mileage and as a bonus maybe a bump in power. Also like to see the transmission shift a little firmer but I guess that will take a rebuild and maybe shift kit package. Thanks again.