SR Idle Problem

[Fahaka]

I have and SR that will not idle.

I performed the swap about a year ago, and have searched all forums for a possible solution.

I will first start with the basics.

The car is an '89 automatic coupe.I swapped the ka and auto transmission for a '94 blacktop and 5 speed transmission.I replaced the t25 with a gt2871r.other mods include: 650cc injectorsFMIC300zx mafs3" turbo back exhaustBikiRom daughter board tuned by CG tuning.

With the stock sr mafs, injectors and ecu the car would not idle. Specifically when the motor is started it will rev up to ~1500 rpm and then drop down to 750 with a bad misfire and then die. Above 1500 rpm the car is fine and runs quite well.

I swapped the sr mafs for a sohc mafs, with the same result. I tried another brand new sohc mafs and it still did not fix the problem.

I sprayed an entire can of carburetor cleaner into the idle air control valve in an attempt to free up a possible stuck valve with no change in idle.

Once we changed to the 300zx mafs, 650cc injectors and bikirom tuned daughter board the car would still act the same way (For the record I was not expecting a change, but I was hoping that this would do something). Still above idle the car ran well and made good power (See also no traction in first or second gear at 20 psi).

In November, due to a faulty actuator I cracked a ring land and decided to remove the motor and rebuild. I machined the block installed cp pistons with eagle rods new bearings freeze plugs, head gasket etc, and while I had the motor out and the manifold off I changed the idle air control valve for a known working used one hoping this would fix the persistent idle problem. It did not.

I have now installed a known working ecu, still no change.Swapped harnesses with a known working harness, no change.Replaced all rubber fuel lines in case one had an unseen leak, no change.reinstalled stock injectors, sohc mafs and stock sr injectors, still no change.

Today I worked a sold 12 hours on this car attempting to get it to idle properly in order to pass emissions here in AZ with no effect

I have run out of possible solutions with the exception of replacing the iacv with a brand new unit.

If any SR experts who have encountered a similar persistent idle problem could chime in on this subject I would greatly appreciate it.

Also when I disconnect the mafs the car idles fine.
Modified by Fahaka at 6:42 AM 5/16/2007

[URAS]

even if the iacv is knackered you should still be able to get a manual idle, using the throttle stop screw.

[Fahaka]

even if the iacv is knackered you should still be able to get a manual idle, using the throttle stop screw.

No even with the stop screw adjusted it won't idle.

[blk180sx]

sorry to here about your problems bro. i would switch back to the z32 mafs and be sure that you have it wired up correctly even the ground wire. i know a few years back there were a few wrong wiring diagrams posted on the boards.