Inナni 7

Background: After owning the car for 4 months I decided that I'd better sort out the pathetic idle. Took off the intercooler and low and behold the TPS wasn't even plugged in. So now thats plugged in and adjusted.

Problem: Still idling around 500-600, and there's a weird "baaaa" noise just when slowly get on the throttle or come off it. Oh and when the revs dropping to about 1500 the car makes this "baaaaa" and carry's on driving like i'm lightly touching the throttle.

Solution: The intake will be thoroughly checked tonight for leaks. The TPS read sweet on the multimeter. There also seems to be a potential exhaust leak, right by the turbo, maybe thats the culprit???

Cheers people, anyhelp appreciated.

Nick

88 Infini

scathcart

Do what you suggested, then adjust the idle.

The noise is your exhaust leak, especially if it happens most notable upon decel, lower rpms, and constant speed.

NZConvertible

Dude, like there aren稚 enough sheep jokes about Kiwis!

Seriously, I known exactly what you池e talking about and AFAIK this is normal and they all do it. The injectors are switched off when you lift off the gas (all EFI cars do that), and I believe as the throttle is closed, one rotor is cut off before the other. Lift off quickly and you don稚 notice, but do it real slow and hold it at that point, it痴 possible to hold it running on one rotor. I致e no idea why Mazda did this, by my 84 Cosmo (12AT) did exactly the same thing, and I致e heard other FC痴 cruise past my making the same noise. It痴 less noticeable if the TPS is properly adjusted.

EDIT: Forgot about the exhaust leak. The gasket between the turbo and the manifold is a common failure at this age. It's about NZ$90 (crazy I know) and will take a few hours if you haven't pulled a turbo off an FC before. I doubt this is causing the noise you describe; when my gasket failed I could hear the leak at idle and it just got louder with more throttle.

Inナni 7

but the weird "baaaaaa" started straight away when I hooked up the TPS. Also there's no screw in the top of the BAC valve to adjust the idle.

NZConvertible

JDM cars don't seem to have these. I use the throttle stop screw on the TB to adjust idle speed.

Reread my post above; I edited it.

Inナni 7

hahaha how convenient that my car now "baaaa's", no wonder I love it!

Yeah I'll definatly get a gasket for the turbo, but the cutting of the fuel is really irratating and is giving my car automatic like qualities. So a full on check of the TPS (again) may do trick? I'm curious as to how my car has been running for months without the TPS even hooked up. (like **** i imagine)

NZConvertible

The TPS isn't used for much more than idle control and the closed-throttle injector cut.