Car won't idle, please help diagnose.

[Torqstr]

ok, let me explain again. With the TPS plugged in the car will NOT idle at all. In other words with it plugged in the car just sputters out and dies. Now I don't know if you've ever tried to tune a car that won't stay running, but it's impossible. You can't be under the hood playing with idle settings and other things with the car running...because it won't stay running. It's not that it will idle rough, it won't idle period.

I'm currently in the process of trying to return as much as possible to the way it's supposed to be from the factory, but unplugging the TPS is the only thing so far that has allowed the engine to stay running.

As far as unplugging things you'd be surprised how that works. It's called the process of elimination. You try blocking off one thing at a time and see if that makes a difference.

And as for the little ports on the back of the intake manifold I'd be more than happy to reconnect them, but no one has been able to tell me what in the hell they're supposed to be hooked up to in the first place.

[lucid]

The vacuum lines seem to me like the intelligent place to start at, I mean a good valve/sensor may as well be a bad one if it's not hooked to the rest of the system. If your car hasn't had an accident where the hood was replaced.....Honda provided a label on the underside of the hood that not only shows you where each vacuum hose goes to each sensor, but each line has a number in the diagram and printed on the actual hose. It's so easy to follow it's ridiculous, the numbers on the hoses are sweet. I tried to find you the diagram last night, but all I could find was the one for the prelude motors, and that's probably only useful if you're doing a swap. If nobody else gets to it before me, I'll take a pic and put it on here tonight. I don't have the car here, but I should go by the garage sometime today. Later

[HondaFan81]

FITV should be tightened down when WARM (put in boiling water) because the valve should be opened when cold (not closed... i.e. tightening it down when it's cold like you did).

[Torqstr]

ok I removed the FITV, soaked it in boiling water then re-tightened it. I also installed a coolant temp sensor & new connector, MAP sensor, and IACV with parts that I got from a car at the junkyard. I then proceeded to hook everything up as factory as possible.

Finally some progress! The car now runs like it just has a bouncy idle. It will bounch between like 1-2Krpm but it doesn't stall. I tried to clear my ECU, then drove it for a few minutes. Checked the codes and I'm still getting a 5 and 41!! I tried 3 MAP sensors so far and still get the stupid code 41! Oh well my car is still missing it's muffler and who knows how much else of its exhaust system. Not to mention I noticed today when I took off the exhaust heat shield that the manifold seems to be cracked. Look at picture below.

Anyway, any other suggestions I could try in the meantime to get the car to idle normally?

[MangoMechaniX]

ok I removed the FITV, soaked it in boiling water then re-tightened it. I also installed a coolant temp sensor & new connector, MAP sensor, and IACV with parts that I got from a car at the junkyard. I then proceeded to hook everything up as factory as possible.

Finally some progress! The car now runs like it just has a bouncy idle. It will bounch between like 1-2Krpm but it doesn't stall. I tried to clear my ECU, then drove it for a few minutes. Checked the codes and I'm still getting a 5 and 41!! I tried 3 MAP sensors so far and still get the stupid code 41! Oh well my car is still missing it's muffler and who knows how much else of its exhaust system. Not to mention I noticed today when I took off the exhaust heat shield that the manifold seems to be cracked. Look at picture below.

Anyway, any other suggestions I could try in the meantime to get the car to idle normally?

Get that exhaust back on. Get something serviceable from the junkyard, at least for now. Are you going to put the car back into regular use, or just for the track? From your picture, it looks like it could also be a bad exhaust manifold gasket (not easy to tell from just a photo).

[Torqstr]

the car will be used as a daily driver. I'm going to just do some basic modifications. Header, Cam, Intake, Exhaust, upgraded ignition system, etc... I will also modify the looks just a little, changing the gauges, headlights & taillights. Later if I can find a good front lip, or not-too-ricey looking ground effects kit I might do that as well. Mostly though I just want a sporty, clean looking little coupe.

[MangoMechaniX]

Others report that the EGR will cause poor idling if it goes bad, or in your case blocked off. Electronic fuel injection requires all these things to work in conjunction to tell the ECU to compute the proper action. You can make a 40's or 50's engine by stripping out everything and going with carburetors.

[Torqstr]

Well it's all pretty much returned to stock as of now. Car actually stays running now, but I still get the erratic idle up and down between 1000rpm - 1500rpm.