Hi, and thanks for reading my post. Recently, I have a little problem with my d15b. When I'm at a stop light, it idles rough and do random misfire. I think it maybe something in link with the fuel pressure. When I disconnect the top vacuum hose of the fuel pressure regulator it seems to idle way better. I guess it could be dirty injector or clogged fuel filter. I have new spark plug, wires, distributor cap, timing ok, o2 sensor ok, no CEL in link with that, straight pipe 2.5'', cold air intake, no vacuum leak, new throttle body with new tps.

Ok, few days ago I went to the scrap yard to get a new TB because I've got CEL for the TPS. Since I've replaced it my idle seems to be as bad as before, but sometimes it jump between 900 and 1500 constantly. It does that only when it's warm and sometimes it stops. It figured out that it was a bad TPS cause when I pull the throttle cable more then suppose, it became normal( but still low )

Ok now something new, I've seen that my post cat o2 sensor is broken, but no CEL, and I don't have any cat. So could it be the problem ? I'm running onto a JDM version of the obd1 ECU p28 and I'm not sure if I'm suppose to have that second o2 sensor or if it doesnt come with that engine normaly. All my wiring is on a OBD2 harness so maybe that second 02 sensor plugg into the harness but not into the ECU ?

 

I've had the rough idle and missfire problem before and It was a cracked Intake manifold.. Just thought I'd throw that one out there? Might just check it to make sure.

 

I'll check it out, maybe it's the gasket that is gone too and I think that it may send wrong info about the tps right ?

 

After replacing the TB, do you still have a TPS CEL code?

The secondary O2 sensor serves only an emissions function so is not the cause of your problem.

 

No I don't but I put my old one back in because it was so bad since I put the ''new'' one in.

 

Regardless of worsening of the idle, you should use the throttle body/TPS that does NOT throw a TPS code. It just sounds like the new TB had an intake air leak most likely from a leaking gasket. Fix the leak and go from there.

Did you also replace the rotor in the distributor? Is it in bad condition?

 

About the TPS, the one that the scrap yard gave me was one from a integra but was the same as mine when you look at it, and there was no leak. I checked. About the rotor I have to ask my buddy which owned the car before. I let you know soon as possible.

 

The problem is solves, it was caused by a bad tps.