that cable sounds like the transmission shift cable. it should have alittle metal bead near the ferrule end, it should be adjusted so there's just a hair of slack with the throttle at idle, and that metal bead is about 1/8th inch from the end of the ferrule... looser == lazy shifting, too tight == upshifting late, downshifting early.

 

Last time I drove the car it shifted pretty good, I only turned the long red bit over the line, seemed to help the car start up better tightening it.

Initially adjusting it caused the idle to surge, but after driving the car around and starting it up again it goes back to stalling unless I give it some gas. It shifts as smooth as pudding.

It does take much shorter to actually idle though, before doing all this work it'd take a half of minute of me sitting in the gas for anything, now its just a few seconds.

 

Does this car have a cold start valve / injector?

 

I believe a 1990 240 did come with a starter valve, although some later LH2.4 ECU's will work without one. The 1989+ intake manifold parts diagram I have shows both the starter valve and a cover plate as options. The 1990 240 LH2.4 wiring diagram does show a cold start valve.

The owner will need to look and see if he has one to be sure... its mounted on the upper side of the intake manifold, directly across from the throttle body, and spraying down towards it, it has a 2 pin electric connection just like the other injectors. I believe its setup to ONLY squirt a second while you're cranking.

adjusting the transmission throttle cable should have had NO effect on the idle.

 

Yep that's what I was thinking . I wasn't sure if he had one but it sure sounds like he has cold start issues which would point to that one cold start injector!

 

Is the Cold Start injector a blue thing near the exaust? I can't find one on my car. Even when its warmed up I have to gas it a little to get it to idle.

 

On the 240, the cold start injector is underneath the intake manifold. A real pain to get to unless the intake manifold is removed.

 

Yes it's under the intake manifold and it looks just like your injectors that are on the top.

 

Also if you have bad injector you will have a stream of fuel rather than a nice atomized flow or mist. This will flood your car and that's is why you may have to partially open the throttle to allow more air to be added to the fuel mixture. You can start your car cold and see if your plugs are wet. If this is the case you can remove your injector and get a hose that will attach to yr injectors and fill it with carb cleaner or injector cleaner . Place a air chuck on the hose and apply 25 psi to the hose and fluid under pressure. Creat a wire harness with a 5 volt light bulb inline on the positive wire connected to a on off toggle switch and you will be able to cycle the injectors until they are clean. Or replace them

If your car is high milage this is a common problem. I have had a fiero that would not run on two cylinders until I replaced the injectors. The plugs were found and very wet with fuel!

 

I'll have to inspect it, the car will start and run for a sec so I think the cold injectors fine. It just wont idle, it'll gradually loose gas and stall out with all the dash lights turning on.

 

I think that my AMMs bad, weeks back the code 121 would show up and I accidentally damaged the screen getting the air filter hoses all back together.

I'll be ordering a 951 ECU off ebay, chances are thats the culprit based off my research. I don't think the ECU was ever replaced in my car.

 

Update

The car starts up alright but wants to idle at 3000rpm before settling down, adjusting the cable above the accelerator cable seems to help, lessening the tension on the upper cable the helped the idle. Warmed up it starts fine.

Making that cable too loose will make transmission shift a little weird so you want it just right.

For anyone reading I suggest not messing with this unless if you're having the issues I just mentioned.

 

Sounds like a temp related issue. Idle usually fluctuates with cold hot temp on tps,MAF, or idle air control issues. Could be just a bunch of junk build up on IAC or throttle body or temp sending unit. New one have been bad.

 

I've cleaned up the IAC, I'll be getting to the TB when the weather gets better, it was a little dirt in the engine bay before I got the car.