I am new here and have been reading up on a lot of topics in searches but I can never find any conclusions to my problem. I have a '93 Prelude Vtec, and I bought a JDM h22a to replace my worn out engine. When the engine got installed I got a custom 2.5in collector and custom 2.5in exhaust w/ no restrictions, AEM CAI. The car idles terrible at stop(surges) (I turned idle control screw and no vacuum leaks) and when I get to 4,500 rpm the engine boggs really badly and won't rev any higher. My mechanic messed with the timing and told me that the engine is running really lean and the computer is trying to adjust it (hence surging idle), so I bought a VAFC for him to tune it. Will this fix it? BTW, I also JUST bought MSD 8.5mm wires, AEM FPR and Rail, MSD 6AL, MSD Blaster 2 Coil, Walbro 255lph fuel pump, 70MM Throttle Body, Port Matched Intake, new dist cap and rotor. Is all this going to make my car stop that annoying idle/bogging or am I gonna have to drive it in the river. Thanks, Andrew

 

if your car is idleing bad when in neutral/park then its your EGR. VAFC only tunes your air/fuel. i would tune it at a local dyno. the VAFC most likely wont fix this problem. check all the vaccuum lines.

 

The best advice I can give you is to put your car back to as close to stock as possible and bring it to your dealer and have them fix it. It may cost a bit more but it will be done right. The WORST thing you can do is bring it to them with an aftermarked ignition, TB, fuel rail, etc. They will just laugh at you. Worry about getting the car fixed right first, then worry about aftermarket ****.

BTW, none of the stuff you mentioned will fix your car. Look at the IAC valve, then try the EGR. You should get a service manual if you want to fix your car right.

 

It ran fine before I had the new engine put in, I know that it will run fine stock, I just can't seem to figure out what I put on it that makes it surge.

 

does that tb have coolent bypass on it, if it does thats the prob. i block them once and my car startd idle surgeing

 

YES!!! It does!!! Thanks for the advice, if this fixes the surging I will finally be happy with my Lude. Thanks again, Andrew

 

i have a 5th gen...........i did the intake coolant bypass........my idle surgess at idle
when its cold outside and the motor is cold(i live in houston so it doesnt happen often)its actually kinda cool

 

Cool??? Haha!!! Wait till you get an exhaust, it sounds like you are revving at everyone. I have a custom 2.5in collector to a custom 2.5in exhaust w/ no cat or restrictions. It gets annoying real fast!

 

let me know if that fixes it