92 Loyale - bad cold idle and performance

[dshaw]

Hi all;

 

I'm working on a friends 92 loyale (4wd, 5-speed, 1.8l SPFI)

He has a new fuel pump and ignition components (coil, wires, plugs, cap, & rotor).

 

The car runs very poorly when started cold - it will usually stall and requires careful increase to the idle (via the throttle) to keep it running. If you put it in gear and go it likely will stall unless you feather the throttle very carefully. Typically when it gets over 2000 rpms or so it smooths out. It also runs decently once its warmed up.

 

I have checked the charging system and it appears that it isn't overcharging. I have checked the ignition timing and it looks good. Fuel pressure is also good.

 

My scan tool, an OTC 4000e, won't work correctly on the car and has me concerned - every time I try to get it to communicate it says it can't. It makes me think I may be looking at a bad ecu/computer. (I have the correct OTC connector and software for this car and am connecting in the right place - by the driver's side firewall under the hood.)

 

Any thoughts?

 

Thank you!

 

Damian

[calebz]

The Aux air valve controls the idle when cold. There have been a couple of posts about this thing maybe, possibly going bad somewhat, kind of recently..

 

You don't need a code reader to get he codes from the car

 

Hre's how you do it

[dshaw]

What can I do to confirm or deny a bad ecu?

 

Thanks!

 

Damian

[northguy]

If the part referenced is the same as the one on my 83 brat, it's the circular part that sits on the breather and controls the gate in the air intake. Pull it off by removing the screw that holds the keeper on, remove the circular part taking care to twist the little J leg off of the flap in the air intake. The test is simple: depress the little J leg, put your finger over the vacuum line hole. If it holds a vacuum, it's good; if not, the diaphram has a hole and it needs to be replaced.

[Skip]

have you given any though to a bad FI coolant sensor?

It is mounted in the upper rad hose connection "goose neck" and has wires coming from it (there are two sensors mounted here, the one with a connector directly on it is for the dash gauge)

I never saw where the recent posts proved fault with the aux air valve (which by the way this car does not have, only the turbos have them)

The other problem these fuel systems encounter is a sticking shuttle in the IAC (Idle Air Control) (maybe this is what Caleb was thinking about?)

This is mounted on the front of the throttle body has an electrical pigtail and can be removed for cleaning.

Hope this helps

[calebz]

Yeah skip .. was Talking about the IAC.. Thanks for the correction.

 

Edit: Previous post edited to include the proper qualifiers.

[asavage]

I can't get my MT2500 to talk to my '93 Loyale either, so don't feel bad.

 

Read codes from flashing LED on ECU -- remove driver's side knee bolster to access ECU, move harness connectors out of the way to see into 1/4" hole in ECU shield. Read U-codes with engine warmed up. Make sure CEL (Check Engine) light is working! Should light and stay lit with key on engine off.

 

Read U-codes, fix 'em. Then read memory codes (for intermittant faults). Ignore them. Then read D-codes after following the D-code procedure exactly -- involves some driving, or running it in gear on jack stands like I did. Then you can clear all the codes.

 

If you can't find the info on how to read mem codes or run D-check proc, let me know. A Google search ought to turn up the info, but if it doesn't, I can write a mini essay. It's too late for me tonight.

[Cheezit]

I am having the same problem with my '93 Loyale TBFI. I followed the manual and found no continuity between ground and the IAC Valve. The only CEL I get is at high speed with plenty of throttle and I am having trouble finding the correct procedure for self diagnostics.

Edited March 23, 2010 by Cheezit