Crazy Eddie

Well, I have been trying to hunt down this idling problem for about a year.
As some of you might know, I have a neighbor and friend, who just happens to know a little bit about 944's
He has helped me through this issue, and a few others, on this 7 year epic journey to get this car finished ...
There have been so many trouble shooting problems, that frankly were needle in a haystack type gremlins.
In fact, at times I was wondering if this car was the AMC Gremlin or a Porsche 944 Turbo ?
After all the the other problems were worked out, up comes this problem with the cars idle ...
It would be very intermittent issue with the idling .. Sometimes it would be fine on start up, other times it would vacillate up and down
Then when the car would warm up ( after 3-5 mins ) the idle would settle down ...
It was driving me crazy .. (short drive, I know). So Tom ( you know, my neighbor :-) had me start replacing all the usual suspects.
This is only a partial list....
ISV and hoses
TPS
Throttle body
Coil
Block temp sensor
MAF ground
Removed and cleaned the brand new MAF
Checked all connectors and grounds..
The list is endless ..etc..
All of these were substituted, with know working ones... ( most complements of Tom)
Then Tom suggested I check the wiring to the DME and KLR, that I did for the Piggy Back ( SMT 6 and the ZT2)
That's when I noticed, that when the boxes were on the floor vs mounted in the foot well, that the car would run fine, but when mounted, the idling issue would rear its ugly head.
I tediously checked all the wiring, pulling apart the bundles of wires trying to find a loose connection .. I was so **** with all the wiring I did. I not only meticulously soldered very wire, but then sealing all of them with liquid tape, and then heat shrinking every connection... Then, when I pulled on the KLR bundle and moved the boxes, while the car was running, I noticed the idle would change slightly..
Then, Tom figured out, by looking at the ZT2 maps, that the car would run rich, when the problem would occur, although the idle would seem fine once the engine was warmed up (as I mentioned, the car would seem to run OK when it was warm ( The problem would be masked )
Then he suggested I pull the DME and then after that, the KLR, and substitute for a known working one.
So I swapped the boxes, and sure enough when we used his KLR the car ran fine ... We swapped them back an forth like 3 x just to make sure.
My DME was fine .. So Tom took a look at the KLR internals (opened up the box), and found some suspect solder joints, that looked cracked to him ...
He then re-soldered the suspect joins, and I re-installed my orig KLR..... and Voila!!! I am back in business ....
Here is a picture that Tom sent me of the suspect soldering, the other image of the Tom's handy work after ...
I am so damn lucky to have a friend like Tom.
Not only does he know so much about these cars, but it's also like having a Porsche Parts Dept in ones backyard !
Oh.... and he's not a bad guy to hang with either
Saved my *** a number of times...
Thanks Tom
Best regards
Ed
ps Rennlist is great .. Thanks to all the others who helped me along the way ..
You know who you are

gruhsy

Sweet! Good find. I wonder how many others out there are like this. I've been trying to help Adam Pitts with his idle issue. I will text him about this one.

Thanks for posting Eddie

odb812

Great news Ed. I hope to see that beauty at one of the local events sometime.

refresh951

I agree Eddie. Tom has also helped me a number of times. Great to hear you got it fixed.

Crazy Eddie

So do I ... believe so do I

He is great !
Thanks guys .....
Still have a few more issues to work out but at least I am moving in the right direction

jlturpin

This is becoming a more common issue as these parts age. Normally see a brief drop of the tach or factory boost gauge goes to center when the car hick ups.

Paulyy

glad to have found the problem! must have been a headache going through all those parts

Crackership

You know, Ed, I've had my DME out and apart a few dozen times and every time I thoroughly check all the solder joints... But it's never occurred to me to do the same to the KLR... I think I'm going to pull it out tomorrow and inspect it. I just want to know that it's good

Thanks for posting! Now I have something else to pull apart and inspect

Ski

Track car would not start before I started to tear it apart - you know just wanted to make sure all that was ok. Ended up swapping out the KLR, after DME swap, and the car fired up like it never did before and idled perfect! It had not been started in at least 6 months! KLR will visit the ECU Dr in Florida.

Glad you got it Eddie, stuff like that can be very frustrating.

michael2e

man that indeed is a needle in a haystack! thx for posting

David Floyd

Tom is a class act

lee101315

I had the SAME exact problem, and it drove me crazy for years...
I would set the idle, adjust everything, it would run perfectly and buzz nicely at 850-900 rpm.
Two days later, BAM! It would surge up and down wildly. No vacuum leaks, new idle speed control and tps...WTF?!

Sure enough, I swapped the DME and KLR set from one of my 951s to the other ( one set had chips installed ) and the problem went to the other car. I have the suspect KLR on a shelf someplace, and now I know what to do. Thanks.

Scott H

Congrats on finding that fix! I'll give my KLR and DME a look over before I go to fire the car up. I know they got wet before so I need to go in there and make sure there's no corrosion forming. I cleaned them out pretty good, but that was a few years back and I didn't check the solder joints.

Crazy Eddie

The tack was jumping up and down along with the idle ( at cold start up )


Honestly it was a freakin' nightmare ..
I was pulling my hair outta my head and I really don't have much left to pull !!
Along with pulling things on and off the car ( I feel like I have taken this car apart and put it back together 10 times )

What was so weird was these boxes have been only in and out of the car a few times and were handled with such care ... but as jlturpin and Tom said, "These are 24 yrs old plus, so stuff starts to happen. "

Thanks Bret and thanks for your sage advice over the years
The KLR was about to head there to the ECU Dr. when Tom said, " Let me take a look at it and see what I can find " He not only did he find the cracks ( which I don't think I would have ever been able to see. One because I can't see like I used to, and two because I really didn't know what a cracked joint looks like, (that was until he sent me a picture of it).
He also thought it was too much of a coincidence of where the suspect joints were.... Here is his quote So we were feeling pretty confident that this might be the answer ... But with my luck I was counting my chickens ...

Hope it helps someone else ..

Yes he is ...
You anit so bad either David

Yea who would have guessed ...
You were lucky to have spare boxes to check it..

Yea.. Again, I never would have guessed it was the KLR ? Simply because the box may have been out of the car once or twice and it was only handled with the utmost care ...
Best regards Guys
Ed

CyCloNe!

Thank you for this, I've been dealing with this same issue a long time and have changed the same items. My car when cold the idle surges back and forth until the car warms and then it settles correctly. I plan on fixing or replacing my computer in the future.