GTS Engine Cut Out - Intermittent
01-08-2014, 12:29 PM
#61
Archive Gatekeeper
Rennlist Member
Rennlist Member
Randy, I have a spare set of brains you're more than welcome to borrow. They don't have PEMs in them but they would run your car well enough to test. Holler if you'd like me to toss them in the mail.
01-08-2014, 01:42 PM
#62
Addict
Lifetime Rennlist
Member
Lifetime Rennlist
Member
Thread Starter
Hard to believe there isn't anyone near you to loan you a set of known good ECU's. If you need, I can send you my tuning/spare set. They have PEMs installed currently, and I'm not sure which map is on them, but you could put your current chips in them if you wanted. I won't be needing them for a couple months. Just say the word and I'll get them wrapped up and shipped out to you.
Randy,
Computers do fail intermittently during overheat conditions, specially when a marginal IC, solder or trace connection expands/contracts due to temperature variations. While I can't speak specifically about the LH/EZK, I had a very similar situation with an aftermarket ECU. It would run great until summer time when cabin temperatures in the footwell increased. Turns out the internal components would "flip out" once the temperature got too high (verified by the manufacturer during warranty claim). It happened during a long cross country drive for me, and the temporary solution to get me home was to remove the carpet cover in the footwell to allow enough air circulation around the computers. One suggestion is to try driving with the carpet cover off to allow more air in that area. See if it still happens after 10-15 minutes during temperatures where it "normally" cuts out? From reading your entire post it sure sounds like a computer heat issue to me.
Good luck,
Carl
Computers do fail intermittently during overheat conditions, specially when a marginal IC, solder or trace connection expands/contracts due to temperature variations. While I can't speak specifically about the LH/EZK, I had a very similar situation with an aftermarket ECU. It would run great until summer time when cabin temperatures in the footwell increased. Turns out the internal components would "flip out" once the temperature got too high (verified by the manufacturer during warranty claim). It happened during a long cross country drive for me, and the temporary solution to get me home was to remove the carpet cover in the footwell to allow enough air circulation around the computers. One suggestion is to try driving with the carpet cover off to allow more air in that area. See if it still happens after 10-15 minutes during temperatures where it "normally" cuts out? From reading your entire post it sure sounds like a computer heat issue to me.
Good luck,
Carl
As always, you are da man. I'll try with and without my PEMS for the test. Will send you a PM - thanks!
01-08-2014, 01:55 PM
#63
Nordschleife Master
Hard to believe there isn't anyone near you to loan you a set of known good ECU's. If you need, I can send you my tuning/spare set. They have PEMs installed currently, and I'm not sure which map is on them, but you could put your current chips in them if you wanted. I won't be needing them for a couple months. Just say the word and I'll get them wrapped up and shipped out to you.
Man, you have to love this community.
01-08-2014, 02:51 PM
#64
Official Bay Area Patriot
Fuse 24 Assassin
Rennlist Member
Fuse 24 Assassin
Rennlist Member
If the LH and EZK swap doesn't fix it, I wonder if those 2 igniters at the front of the engine under the hood are going out. I was pointed to those a while back for a possible fix as well to a strange cut out issue I was having as well. It wasn't as violent as yours, but the car would just spontaneously lose power while cruising at 70, then recover after about 15-20 seconds. I haven't had the same issue again after going through the whole engine compartment, cleaning grounds and ignition wire connectors.
01-08-2014, 08:22 PM
#66
Addict
Lifetime Rennlist
Member
Lifetime Rennlist
Member
Thread Starter
Randy,
Computers do fail intermittently during overheat conditions, specially when a marginal IC, solder or trace connection expands/contracts due to temperature variations. While I can't speak specifically about the LH/EZK, I had a very similar situation with an aftermarket ECU. It would run great until summer time when cabin temperatures in the footwell increased. Turns out the internal components would "flip out" once the temperature got too high (verified by the manufacturer during warranty claim). It happened during a long cross country drive for me, and the temporary solution to get me home was to remove the carpet cover in the footwell to allow enough air circulation around the computers. One suggestion is to try driving with the carpet cover off to allow more air in that area. See if it still happens after 10-15 minutes during temperatures where it "normally" cuts out? From reading your entire post it sure sounds like a computer heat issue to me.
Good luck,
Carl
Computers do fail intermittently during overheat conditions, specially when a marginal IC, solder or trace connection expands/contracts due to temperature variations. While I can't speak specifically about the LH/EZK, I had a very similar situation with an aftermarket ECU. It would run great until summer time when cabin temperatures in the footwell increased. Turns out the internal components would "flip out" once the temperature got too high (verified by the manufacturer during warranty claim). It happened during a long cross country drive for me, and the temporary solution to get me home was to remove the carpet cover in the footwell to allow enough air circulation around the computers. One suggestion is to try driving with the carpet cover off to allow more air in that area. See if it still happens after 10-15 minutes during temperatures where it "normally" cuts out? From reading your entire post it sure sounds like a computer heat issue to me.
Good luck,
Carl
Didn't miss a single time on the 40 minute drive.
Sure seems to be pointing to the ECUs rather than something in the engine bay, doesn't it.
Ignition power?
http://jenniskens.livedsl.nl/Technic...6/MyTip669.htm
http://jenniskens.livedsl.nl/Technic...6/MyTip669.htm
01-08-2014, 08:37 PM
#68
Rennlist Member
Yup, sure does. I think definitely a good idea to swap out computers and narrow it down further.
Cheers!
Carl
Cheers!
Carl
That one got me thinking, so before the drive home today in mid-60* temps, I pulled the carpet and footwell board away from the CE panel and ran the AC into the footwell area.
Didn't miss a single time on the 40 minute drive.
Sure seems to be pointing to the ECUs rather than something in the engine bay, doesn't it.
Is that link referencing the ignition switch units (aka ignition modules or igniters) as mentioned by Mongo? That was another item that was/is suspect.
Didn't miss a single time on the 40 minute drive.
Sure seems to be pointing to the ECUs rather than something in the engine bay, doesn't it.
Is that link referencing the ignition switch units (aka ignition modules or igniters) as mentioned by Mongo? That was another item that was/is suspect.
01-08-2014, 08:48 PM
#69
Addict
Lifetime Rennlist
Member
Lifetime Rennlist
Member
Thread Starter
01-08-2014, 10:01 PM
#70
Addict
Lifetime Rennlist
Member
Lifetime Rennlist
Member
Did not see an answer to this...You still have the ignition monitoring relay ?? it has the power to cut off injection to 4 cylinders can malfunction and take out all 8 .... ,
it too is under the carpet cover
The ignition exciters/ modules on the hood latch panel usually take out only 4 cylinders as one fails not all 8 ...
it too is under the carpet cover
The ignition exciters/ modules on the hood latch panel usually take out only 4 cylinders as one fails not all 8 ...
01-09-2014, 12:56 PM
#71
Addict
Lifetime Rennlist
Member
Lifetime Rennlist
Member
Thread Starter
Did not see an answer to this...You still have the ignition monitoring relay ?? it has the power to cut off injection to 4 cylinders can malfunction and take out all 8 .... ,
it too is under the carpet cover
The ignition exciters/ modules on the hood latch panel usually take out only 4 cylinders as one fails not all 8 ...
it too is under the carpet cover
The ignition exciters/ modules on the hood latch panel usually take out only 4 cylinders as one fails not all 8 ...
https://www.928gt.com/t-9295fuse.aspx
01-09-2014, 01:10 PM
#72
Archive Gatekeeper
Rennlist Member
Rennlist Member
Brains in a box, headed to the post office at 11.
The ignition control monitor (ICM) relay is the deck-of-cards-sized clear plastic relay mounted on the bottom of the brains' frame. Has a white square 9(?) pin connector. Get three 0.250" spade lugs, and two 3" pieces of wire. Make a 'Y' shaped jumper, pull the plug off the relay, and plug the middle of the 'Y' into the center plug hole, and the ends of the Y into the holes with the red/yellow stripe and red/green stripe wire. This bypasses the ignition control monitor to take it out of the equation for diagnostics purposes.
Porsche also makes a "plug bridge" relay used in the 944S2, (not sure what it's for in that application) that will work as a more permanent ICM relay bypass, 928 615 175 00. But it's probably best to keep the ICM system functioning and 'in the loop', so to speak.
You can see the pins on the bottom of the ICM in the back of the lower picture, behind my finger:
The ignition control monitor (ICM) relay is the deck-of-cards-sized clear plastic relay mounted on the bottom of the brains' frame. Has a white square 9(?) pin connector. Get three 0.250" spade lugs, and two 3" pieces of wire. Make a 'Y' shaped jumper, pull the plug off the relay, and plug the middle of the 'Y' into the center plug hole, and the ends of the Y into the holes with the red/yellow stripe and red/green stripe wire. This bypasses the ignition control monitor to take it out of the equation for diagnostics purposes.
Porsche also makes a "plug bridge" relay used in the 944S2, (not sure what it's for in that application) that will work as a more permanent ICM relay bypass, 928 615 175 00. But it's probably best to keep the ICM system functioning and 'in the loop', so to speak.
You can see the pins on the bottom of the ICM in the back of the lower picture, behind my finger:
01-09-2014, 07:47 PM
#74
Race Car
The first place I would check would be the crank position sensor where it plugs into the harness. The plug gets brittle and crumbles, compromising the connection, causing the engine to briefly stall when hitting a bump, but not always.
My car had a crumbling sensor.
My car had a crumbling sensor.
01-09-2014, 08:36 PM
#75
Electron Wrangler
Lifetime Rennlist
Member
Lifetime Rennlist
Member
Alan