924Board.org

[Eturbo924]

Ok so here is the deal. My 1982 924 has been having the low rpm blues... as I have talked about before in posts.

Anyway I played with the timing and set it to where a 1982 should be as the haynes notes anyway. Turns out it ran even worse. So I advanced it a bit further then stock and she settled down a bit. But still missing and hesitating below say 3500 rpms.

So I saw the post about setting the idel speed and tried playing with that a bit. Turned the air screw in all the way and then backed it out 2.5 turns. Now the idel is around 1100 rpms... but hmmm... car is much better at low rpms. But it still has a miss here and there. So I began to wonder if maybe she is running too lean. Since I do not have a sniffer for the exhaust I tried some thing a bit different. I closed the circuit at the throttle body which tells the car it has wide open throttle. WALA! (sp?) Car has tons more power!

So... knowing what I did above. What do you guys think the issue is? The car should not always need to be thinking it is at full throttle right? Even though I am quite happy with the results I would rather set the car up correctly.

Oh when that switch for full throttle is closed you can hear the fuel meter (I think that is what it is called) buzzing.

Let me know what you think.

Eric
_________________
1982 924
1992 968
2003 C4S
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[gohim]

Like I just wrote to someone else with a 82 924, you cannot adjust the idle speed and mixture like you did on the earlier cars.

The electronic idle stabilizer will fight you, and unless you get the timing, idle speed, and idle mixture set exactly correct, the car will never idle properly both hot and cold, and you will always have a bad flat spot.

You MUST temporarily disable the idle stabilizer when trying to adjust the idle speed or idle mixture (Bypass the Idle Stabilizer by plugging the two round connectors into each other, or, (much more easy) simply unplug the spade connector on the left inner fender wheel arch. MAKE SURE THE IGNITION IS OFF WHEN DOING THIS.

Shorting out the WOT switch bypasses the O2 sensor circuits, and you will never pass smog emissions testing.

You don't need any special tools to get the car to run correctly, but you will need a simple timing light.

Look up the old thread that I posted that explains how to get the engine set up right. When you have everything in good shape, the flat spot will disappear, and the engine will idle fine when cold, hot, or even anytime you have the ac on.

[Eturbo924]

That is the post that I was using even though I used to be able to set the car with out any issues... but I think my mechanic had bypassed the O2 circuit before. Actually he unplugged it. My car never had any problems passing emissions testing. Now it no longer has too. They do not test it past 20 years old over this way.

I will perform the rest of the posts suggestions and see how it goes. I had already made a copy of it and sent it to my e-mail.

Also I have a timing light and had set the engine to 10. At that it would not make enough power down low. If I went even futher back towards 0 it got worse. So it is around 13 to 15 now and running great. Of course with the O2 system defeated.

So... question... do you feel she is running lean?

Yeah yeah yeah I will do the set up... ok...
_________________
1982 924
1992 968
2003 C4S
Parts Parts Parts and More parts.
E-mail me for parts you need!
Drive Fast!

[gohim]

Without playing with the car myself, I have no idea of where the setting are, or far far off they are.

I can tell you that it sounds like the idle adjustements are set up wrong.

I had a similar situation to what you describe, when I bought my 81 924, after the smog testing station worked on the car. The problem was almost as bad before they touched it, and the Previous Owner had a hard time getting the car to start and stay running. The Previous Owner had someone who didn't know what he was doing servicing the car, and as a result, the idle adjustments were totally screwed up.

Once I figured out what the problem was and reset everything, the running problems dissappeared.

Once the setting are as fouled up as yours sound. the only way to correct the engine running problems is to set everything back to stock.

[Charlane]

This *smells* like an injection problem and it might not be firing one of your cylinders correctly. However, that being said, it could still go back in that your mixture is not synchronized per cylinder or it could be electrical. This could start at the coil, go to the spark plug and all the way to the cylinder. Get your shop guy to look into what it takes to get all cylinders to fire identically AND THEN consider your idle. Check your voltage out at the battery, too. I find that I get good performance if I have a little over 13+ volts and yes, your idle would have a direct impact on that.

I'm going to sound like a broken record, but whip out a $3 tube of die-electric grease and pull off the spark plug end caps and connections to the coil and dab some of this on. I use a paintbrush I put aside just for this purpose. Be careful about polarity so as not to cross it. I put this stuff on all of my spade plugs and ground EVERYWHERE (fuses too). It might not solve the problem, but your voltage flow will be much more consistent. It might run far more smoothly. If this helps, please write back. I want to know that I told you the right thing.

Charlane
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Electra is Here......

One 1980 924 Turbo
One 1990 KZ1000P (CHPS) Motorcycle
One 1984 244 Turbo Volvo (B21FT) (I installed this engine myself)
One 1977 240D Mercedes Benz
One 1970 Chevy Impala

[John Brown]

Don't confuse the O2 sensor function with the enrichment functions of the (same) black boxes.

Your mechanic may have disconnected the O2 sensor; and in fact I also recommend same as these early efforts at fine tuning mixture tend to cause 'hunting' which causes 'surges' that are very hard to get rid of. But, with the O2 sensor disconnected/deactivated that does not affect the enrichment at WOT or the idle stabilization.

Disconnect the O2 sensor system (not necessarily the sensor itself) and adjust the mixture just as you would on any car; by ear.
_________________
John
80 931 - #931 44Cup
99 Escalade - tows track cars
gone but not forgotten: original 924.org car - 82

[leadfoot]

Iv'e read that the control plunger really only sets the idle mixture and the true fuel readings are a factor of control pressure. If anyone can verify this it would be nice to know.
But if your worried about running lean pull out your spark plugs and look at them, their condition will tell you what you need to know about your air/fuel ratio.
Consider your fuel filter is in need of replacing, and check the control pressure settings.
Leadfoot
_________________
1981 ROW 924 Turbo -
carbon fiber GT mish mash
LS1 conversion in progress...

[numbbers]

Well, if you shorted across the full throttle enrichment switch, all you did was force the fuel mixture to full rich. If this improved your performance and drivability, then I would guess your problem is that the fuel mixture is too lean. That may be a misadjustment, but it may be something else, like a vacuum leak.
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1980 924 Turbo