quick question

[Brandon_l1000]

hey fella I am working on the old ladies car it is a 99 Honda passport. It has a miss that I have been trying to fix for only god know how long. I even took it to a mechanic and he couldn't figure it out. when it is idling it will rev up and down. sometimes to point that it dies. I also noticed that as it rev up and down all the light brightin and dim its not bad just noticeable. first thing I thought of was a bad alternator or a bad ground, but all that seems fine. so do you think these to problems are related and if so any suggestion on what it is? also when you give it gas the light stay bright. also can a bad 02 sensor cause your lights to dim?

 

[Driver4r]

On my buddys honda accord, theres a high idle sensor or something. And his will rev up and down at idle.
Sounded pretty funny when we put the fart can on it.

 

[77 K20]

I had the same thing on an older Audi 100. It was the IAC valve (idle air control valve). Hondas have the same thing. Might check into that. Sometimes you can just remove and clean them. It worked for me for around 6 months then had issues so I replaced it.

 

[Brandon_l1000]

yea I changed the idle air, the mass air flow, I have put new plenum gaskets on it, I have been over it with a fine tooth comb looking for vacuum leaks, I have compression tested the cylinders, changed spark plugs, changed the fuel injectors, checked the fuel pressure regulator, checked all the coil packs, and nothing. the plenum gasket was bad and that helped a lot, but didn't fix it. the only other thing I can think of is the 02 sensor.

 

[HotRodPC]

I remember you bringing this hunk o' **** up long ago when you were doing the plenum gaskets IIRC. Not real sure about Honda's myself. I've heard on another vehicle, MAP (Manifold Absolute Pressure) sensor caused a similar issue and was not detected by the Check Engine light. Not even sure this model has one, but just something you might do a bit of research about and find out if it's it.

 

[Brandon_l1000]

piece of **** is right man but she got it for 700 bucks so I cant complain to much lmao it would be a good car if I could figure out what the hell its problem is lmao

 

[woodsrider250]

Still sounds like an air leak, or IAC valve. It's a 99, what codes is it throwing?

 

[foamypirate]

Just a thought, you might want to check an Isuzu forum for the same problem with Isuzu Rodeo's. The Honda Passport wasn't really a Honda, it was just a rebadged Isuzu Rodeo.