Car is a 1988 C4 with L98/TPI w/A4. I have been researching and searching the Forum's.

I have a High Idle problem that I have been trying to resolve, I have did a Tune up of the usual parts, rebuilt the Throttle body with new gaskets, New IAC Valve.

Problem started up after a 100 mile trip (with a few stops). After getting home, the Idle was high. On resetting the Min Idle (450) and TPS setting (could only get to .55 or .53), the High Idle is still there aftrer plugging in the IAC.

I don't think I have a Leaky Injector, as all of the Spark Plugs are reading good. I will try and get a Fuel pressure gauge and see what the leak down is like tomorrow. Also a few time, there was hard starting, Had to assist starting my flooring the throttle after a few attempt to start (cranking for a few seconds a few times)

I have used WinALDL to assist, I am new to using this and the the TPI system. I wonder if someone could take a look at this screen shot and tell me if there is anything abnormal !? Any advise would be good.



Thanks.

 

Dunno much about WinALDL myself - seems to me that it was a DOS prog 20+ years ago.
Assuming it's similar to newer software, there are a few problems in the jpg you show.

Follow along, they aren't hard to spot. Your data record says:

1. Your IAC valve is ~wide open at 144 counts. Did you want it to be?
2. Your ECT is shown at 220+*F. That seems a little high for January.
3. Your RPMs are at 0. Was the engine off at the time you made the record?
4. Your BLMs are lean at 136. It's not clear to me what that means if the engine is off.
5. The MAF is reading at 23 g/sec. Idle air would typically be more like 6-8.
If the engine was off, why didn't it read at 0? The TPS says the throttle is
closed so I assume the engine was either idling or off.


If the engine was running at the time you made the data jpg, the IAC being
stuck open would cause the idle to be out of control. But from the data shown
it's impossible to draw any firm conclusion.

You can't do much with data unless you know at what speed the engine is
turning, or that it's correctly showing the status of the engine sensors.
Maybe you need to invest in a better data cable, or some better s/w?

Check over on the TGO board for better software/hardware/ECM trouble shoot
info, along with upgrading the ECM to later equipment and programs. Unless
your hobby is working on antique computers/progs, the newer stuff is always
going to be easier to use in the long run.

HTH

 

It was a snap shot as I had just turned it off, the rpm was 1000-1100

1. No
2. Yeah.. I need to see what is causing the High Temp
3. 10000-1100
4. It was about the same running
5. it was idling for the snap shot..

I will get another snap shot running. The IAC valve is brand new, the old one was stuck in position. Is there anyway of testing the function of the IAC either installed or removed ?

Well upgrading would be nice. but I don't know what impact it would be on the SMOG test/inspection.

 

Doc J.. If you can pm me with your E-mail address, I can send you a Excel worksheet of the data that was capture while running and a short drive from last night.. Not sure how or where I can post for you to pickup..

 

you can test the IAC off the car, unscrewing the IAC valve, connecting it to the connector, and turning on the key....please be aware that this will cause the IAC to activate, and may shoot the pintle across the garage at great speed!!, so don't aim it at anything!! ask me how I know??!! As far as your snapshot...you need to replace your coolant sensor...it is used for you fuel calculation by the ECM. That's one reason your BLM's are high...MAF readings are too high for that idle...should be around 10-10.5....now, if you just shut the car off, and then took the snapshot, those MAF readings are bogus...my maf usually shows around 23, when the key is on, but the engine is not running...so if that was the case, we need to see some readings with the car running....but check that CTS first....

Cheers,
Michael

 

Well.. it is better.. but I am still a bit worried, Idle has pop up afew times for no reason.. I see that the O2 was lean and the Rich/Lean counter had a bit of a higher count.

Also, it seem that when I plug my cable and have WinALDL it is making it run at a high idel 1000+, It returns when I remove the term B.

Here is another snap shot.. Better MAF and IAC, but I think it is running rich at times. what do you guys think of these numbers now..?

I am still learning about what all of these parameters and numbers mean. Thank to you all I have been able to understand more of what is going on.

 

Hard to tell from just a snapshot, but here goes...MAF looks ok, IAC at 34...I like 20 or less, but 34 is not bad...INT @ 124 is ok, BLM @ 129 is ok ,BPW @ 1.45 would be alright,the pieces I wonder about are the o2...were you in closed loop? if so, then it is in the swing range, if not, then it looks a little low for open loop...I assume from the rich/lean, that you are in closed loop, with that many counts...Coolant...is your fan running??? I assume you are at idle, maybe sitting in your garage?? If so, and your fan isn't running, then this is too high...if it is running, then you maybe ok....This is why it helps to see more than a snapshot, as we really can't tell what is going on, without seeing the trends, and what is happening before and after the snapshot. Hard to make a determination if we don't know if you just fired it up, or it has been running for a while....if this is a stock chip, then yes, you will have a higher idle when connect to the ALDL, as the stock chip has an adder for the ALDL...

Cheers,
Michael