RXeckless

iTrader: (11)

I search around a bit did not find anything specific to my situation.

Running Hot, High Idle.

Recently my 1992 JDM FD X Type has been blowing vacuum hoses and inter-cooler couplers at the track under load. Last evening after a short trip to the local speed shop I notice my idle was around 1600 rpm's and the rad fans stay on a good 15 minutes after shut down with the key turn on. At cold start-up after a short period the idle settles in to the normal 750 to 900 range only after driving the car does the issue arise. The high revs at idle after the car is really warmed up suggest the engine is trying to cool it's self. Also at the track this weekend I blow off the hose going to the MANIFOLD ABSOLUTE PRESSURE SENSOR after which she idle erratically and black smoke puffed out of the exhaust till we figured out that the line had blown off. Coolant Temp seem to be in normal operating temperature but till I get my PFC (should be here soon) in I can not say for certain. Vacuum is at 18 at idle, 10 while cruising, but boost does seem a little erratic with boost 8-10 then maybe 6-8 then back to my norm 10-12-10. In other words damn weird. What gives, any ideals, what's going on.

The engine is not heavily modified presently with a stock ecu, only Pettit's Intakes, Power pulley, boost gauge, RB exhaust and Pettit's 185 deg Fan Switch.

Thanks, any help would be appreciated.

Sgtblue

iTrader: (16)

The high idle after warm-up and driving suggests a vacuum leak developing when things get heat-soaked.

RXeckless

iTrader: (11)

Thanks, I'll do more hunting this evening! Thought I got them all, time for the HT hoses kit!

KenSpeC

iTrader: (16)

Hey Rick, do you have a fast reacting IAT? (intake air temp sensor) or you still using stock? The stock ones tend to get heat soaked, cause hot start issues and idling too. Do the vacuum hoses like we discussed and look into the Fighters garage IAT.

RXeckless

iTrader: (11)

Believe stock, I've never change it and most likely the previous owner did as he never drove it.

Sgtblue

iTrader: (16)

I'm not sure if it would have any effect on your issues, but removing and cleaning the idle air control solenoid might be worth the time. It's on the back side of the UIM but easy to reach. Just unplug it and remove two 10mm nuts. I sprayed some brake parts cleaner in it and gotten alot of black soot/carbon/crap out of it. Just be careful with the gasket.

Narfle

iTrader: (16)

I think you have a small vacuum leak that get worse when your car warms up, as others have suggested.

RXeckless

iTrader: (11)

Thanks, everyone. I search in vain this evening no visible leak, maybe in the rats nest which is a job for the weekend. Sgtblue I'll also try cleaning the idle air control solenoid.

RXeckless

iTrader: (11)

Well, it does not seem to be a vacuum leak sprayed carb cleaner on and around every vac hose with no throttle change even after a good heatsoak ..... hood closed revving to 7K off on for over half an hour. But did find that the throttle cable does have something to do with part of the problem may be sticking as it gets heatsoaked after a hour got her down to 900 rpm to 1K. Still going to change out the IAT sensor if I can get one of the better ones eg: Wannaspeed or Fighter. Also will order the HT hose kit in the next few days. But after screwing around with the throttle cable on warm-up she running 700 rpm at idle till heatsoak kicks in, she's never been that low. Still have not tried cleaning the idle air control solenoid maybe tomorrow. Just want to get back to the track soon which is only way to really see if the problem is getting better. F#@K I hate this car right now, but this will pass!

joel_rx7

iTrader: (7)

Stupid question but did you check whether your rad fan are operating as they should?

With the Pettit's 185 deg Fan Switch they should kick fairly soon.