I have an 84 GSL-SE fuel injection. When i start my car itl sit pretty nice at about 1000 rpm. Once my car warms up, it will sit at about 1500 rpm. Anyone know why? or how to fix

 

Heh, thats a little backwards, lol. It should idle high when cold, then drop when its warm, lol. I only have my Dads -SE to work on/look at, and my Dad drives it, I know almost nothing about it, sorry, lol.

~T.J.

 

Start the engine cold, and adjust the hi-idle and the screw that adjust's the 'i guess' it's a thermo pellet.
Adjust the hi-idle to anywhere from 1200 -1500 RPM's,
and then wait for the engine to get to temp, when there,now turn the 'real' idle screw to bring down the RPM's anywhere from 750- 900 RPM's should be ok.
Turn off the engine and hook up the 2 test light gizmo's to the green connector, make sure you have the key turned ON, and set the TPS untill you get 1 light, now start the engine, if the idle needs adjusting, then JUST the idle screw.

 

Maybe a leak somewhere in the intake? Also try cleaning the AFM...

 

There are several different mechanisms that control idle in the 13b EFI engine (found in 84/85 SE's). What you're describing could be due to several different causes, but if you understand each of the components in the idle system, it may help you to diagnose an odd idle condition.

1) Cold Start - this is the green plastic 'tube' sticking out of the left side of the Throttle Body (TB) when standing at the passenger side of the engine bay. Connected to it are 2 coolant hoses, in and out, which tell the 'thermo-pellet' when the engine is hot or cold. If cold, this thermo-pellet closes off the secondary air passages in the TB, resuling in a slightly rich mixture which is sometimes required in cold climates to start and run reliably. There is a cam that the throttle lever slides against which adjusts these 'choke' butterflies - when starting the SE, press accelerator pedal once all the way to the floor, then release and turn key.

2) Air adjust screw - located at the top of the TB, this is a flat-head screw that is inset slightly. This controls the air bypass going to the RE-EGI 'Dynamic Chamber' that indirectly controls idle speed. When the Air Adjust is off, you may not be able to adjust the idle with the other adjustments. Get the Factory Manual or the on-line suggestions and reset this screw location to factory settings. This is also sometimes referred to as the 'Idle Fine' adjustment.

3) Idle Gross adjustment - this is a small copper colored locknut on a silver screw to the right of the TB and attached to the Primary Throttle butterfly valve rod. This idle adjustment is used to make large adjustments to idle settings, and is not a 'quality' but a 'quantity' adjustment - i.e., faster and slower, not smoother. Set this to adjust hot idle to about 850-900 rpm on an SE - SE's idle faster than 12a carb engines.

4) BACV - On the driver's side of the Dynamic Chamber is the Bypass Air Control Valve, which performs 2 functions; a) to allow air to bypass the Primary butterflies to keep idle running smoothly, and b) to adjust idle speed when you turn on A/C or electrical devices. This valve is not adjustable but should be cleaned thoroughly to ensure proper functioning.

Based on your description that the idle INCREASES when warm, you may be looking at issues with #1 or #4. You can remove and clean #4, but #1 is fixed to the TB. If the idle speed changes quality when you turn on electrical equipment, you may only need to remove and clean the BACV valve to restore smooth idle.

There is an on-line help for SE Idle Issues - I hope someone can post that for you. Good luck, the work is worth the effort when you get your SE running well.

I have chosen to settle with some idle issues to retain acceleration and performance at higher RPM's, but this is what I've learned through trying to get it to idle at 900 and smooth.

 

Ive been to the GSL-SE idle problem site many many times, but there is nothing there to fix high warm idle, only cold

 

Jim
I've posted a couple of replies to a number of your posts - all on the same problem. I don't know if you have actually done any of the suggestions because you don't post after we have offered ideas.
Anyway, Londuck has provided a good overall view to the idle adjustments on the SE and I'll offer a couple more:

1) First off, you are idling too low on start up - this is probably due to the cam / roller adjustment being out of place. Before you even start the car, take a look at it (when the cars cold) and determine if the roller is snugged up against the cam - the roller should be about 1/4 of the way up the cam - if you have a manual, it will explain where the roller should be. If you don't have a manual, go to the mazspeed.com site - check under the "facts" section and scroll to the bottom of the page - you will see "See the entire factory manual here" - click and you will have access to the '85 SE manual.

2) Once you have that adjusted, get a can of carb cleaner and clean up the linkage on your throttles - then - get a can of WD40 and lube all the lingage for the throttles - work them around until they move freely and snap back into position as they should. also take the BAC off and clean it up with the carb cleaner and lube it as well/

3) Now start it up and run it until the roler/cam release (seperate from each other) - your idle should drop. If it is still way too high, bring it down using the throttle stop screw - Longduck mentioned it earlier and it's covered in the the site "Solving GSL-SE idle problems" and you know where that site is. Once you find that little screw (it's close to the cam/roller adjustment screws), first close off the air bleed screw on top of the intake (almost all the way) and then adjust the small screw with the lock nut for the throttle stop "clockwise" until the idle drops down to about 500rpm.

4) Now set your TPS while the car is still warm

5) Finally, adjust the air bleed screw "Out" until the idle is up to 800

Remember, any time you adjust any of the throttle adjustments, you will need to reset the TPS.

Now go and do all these things and see if it doesn't solve your problem

 

ive actaully done almost everyhting everyone has said, but i can never locate the cam roller adjustment thing, or the high idle screw which people keep referring to, and ive tried the idle adjust screw that sets the farthers the idle will release to when you let off the pedal, it wont go any lower for some reason. Ill start retryting everythign tomorrow after school. My main problem currently is that i never have time to work on it when its "cold". I get up nd go to school, get home nad its warm the rest of the day basically. Maybe this weekend

 

also, when reading the GSL-SE idle solution page, it mentions the BAC valve. They make it sound like its inside the engine/fuel injection somewhere, how the hell do i find it. Just a location would be nice. Behind wat, or wat do i have to remove to get at it. GSL-SE idle page isnt written that good, so it confuses me alot.

 

You've GOT to find where these pieces are! No way to adjust this monster without knowing what you're working on and what you're doing (or at least vaguely).

Also, check your cruise control cable. It can come partially pulled out from the holder/hinge and give you an elevated idle. NO adjustment on the TB will fix that.

jeryj