Help! Stranded... (long)
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Joined: Jun 2001
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From: Arlington, VA
Help! Stranded... (long)
Had to drive up to NJ today (about 130 mi. from my home in DC) for work. Got about 110 mi. into the trip and suddenly lost almost all power from the engine. Just like flipping a switch. Best way I can describe it is that it felt like the engine's compression was slowing it down. I managed to limp to where I was going, but had to leave the 928 there (got a ride home with a co-worker). Now I have to go back up either tomorrow or Tuesday (more likely - less traffic) and bring it back somehow. I'm hoping that I can bring it back under its own power (with help from you guys!) vs. on a flatbed... The car is a 1980 Euro 5sp. (CIS injection) Here are the symptoms:
1. Starts o.k. - no excessive cranking necessary.
2. Idles low - about 600 rpm. vs the normal 850-ish.
3. When you attempt to give it gas, the engine revs up to about 2000 rpms if coaxed gently. If I depress the accelerator beyond a 'feather touch', the rpm's drop and the engine runs very rough (sort of back-fire-ish...). Under a load, on a flat surface, I can coax the car to about 40 mph, but it has absolutely no power if I encounter a hill. (owing mostly to the fact that I can't give it gas without making it cough and sputter)
4. The warmer the car gets, the worse the problem seems to get. After running a while down the road, the "max rpm" I could coax out of it before it started missing dropped from 2000 to 1600 to 1200.
What I have tried:
1. removed, inspected, and "roughed" (very lightly with a nail file) contact points on inside of distributor cap/rotor. No moisture or corrosion found. Also removed coil cover and checked for loose connection or corrosion. None found. Plug wires APPEAR to be in good shape (none hardened or cracked), although I don't know for sure when they were last changed.
2. Put in a bottle of STP Gas Treatment - in case perhaps I had water in my fuel system (it's been rainy here of late)
3. Checked vacuum at the 4-way connector that goes to the HVAC system off the brake booster by unplugging it. HISSSSSSS revealed that at least THAT part of the system has vacuum. (not sure what good that does me, though).
When I depress the gas pedal "too much", I do smell fuel. This makes me think that perhaps I am running rich when I do that. I'm thinking one of two things may be the culprit:
1. Bad plug or wire? (i.e. ignition)?
If this sounds plausible, is there a "parking lot tests" for finding out which is the culprit without removing the lot?
2. Vacuum advance? If I have a vacuum leak somewhere and the timing is not advancing as the car engine spins up, could this cause these symptoms?
If so, could I check for this by starting backwards? (i.e. putting a mity-vack on the end of the vacuum-advance tube and checking the line that way?)
3. Other - known to those wiser than I!
All suggestions are greatly appreciated!!
Brian Bowman
1980 928S 5sp. Euro
Silbermetallic/Blau
Temporarily Kaput!
<img src="graemlins/crying.gif" border="0" alt="[crying]" /> <img src="graemlins/crying.gif" border="0" alt="[crying]" />
1. Starts o.k. - no excessive cranking necessary.
2. Idles low - about 600 rpm. vs the normal 850-ish.
3. When you attempt to give it gas, the engine revs up to about 2000 rpms if coaxed gently. If I depress the accelerator beyond a 'feather touch', the rpm's drop and the engine runs very rough (sort of back-fire-ish...). Under a load, on a flat surface, I can coax the car to about 40 mph, but it has absolutely no power if I encounter a hill. (owing mostly to the fact that I can't give it gas without making it cough and sputter)
4. The warmer the car gets, the worse the problem seems to get. After running a while down the road, the "max rpm" I could coax out of it before it started missing dropped from 2000 to 1600 to 1200.
What I have tried:
1. removed, inspected, and "roughed" (very lightly with a nail file) contact points on inside of distributor cap/rotor. No moisture or corrosion found. Also removed coil cover and checked for loose connection or corrosion. None found. Plug wires APPEAR to be in good shape (none hardened or cracked), although I don't know for sure when they were last changed.
2. Put in a bottle of STP Gas Treatment - in case perhaps I had water in my fuel system (it's been rainy here of late)
3. Checked vacuum at the 4-way connector that goes to the HVAC system off the brake booster by unplugging it. HISSSSSSS revealed that at least THAT part of the system has vacuum. (not sure what good that does me, though).
When I depress the gas pedal "too much", I do smell fuel. This makes me think that perhaps I am running rich when I do that. I'm thinking one of two things may be the culprit:
1. Bad plug or wire? (i.e. ignition)?
If this sounds plausible, is there a "parking lot tests" for finding out which is the culprit without removing the lot?
2. Vacuum advance? If I have a vacuum leak somewhere and the timing is not advancing as the car engine spins up, could this cause these symptoms?
If so, could I check for this by starting backwards? (i.e. putting a mity-vack on the end of the vacuum-advance tube and checking the line that way?)
3. Other - known to those wiser than I!
All suggestions are greatly appreciated!!
Brian Bowman
1980 928S 5sp. Euro
Silbermetallic/Blau
Temporarily Kaput!
<img src="graemlins/crying.gif" border="0" alt="[crying]" /> <img src="graemlins/crying.gif" border="0" alt="[crying]" />
Three Wheelin'
Joined: May 2001
Posts: 1,641
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From: Hudson Valley NY
brian,
Vacuum is not the problem; backfire would point to ignition coil, control unit or AFM. Check the distributor it could have became loose, movement from side to side. Bring a coil with you try that first. A possibility is plugged fuel filter or fuel pump going bad.
Good luck
<img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />
Vacuum is not the problem; backfire would point to ignition coil, control unit or AFM. Check the distributor it could have became loose, movement from side to side. Bring a coil with you try that first. A possibility is plugged fuel filter or fuel pump going bad.
Good luck
<img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />
Thread Starter
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Joined: Jun 2001
Posts: 71
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From: Arlington, VA
Thanks for the quick reply, Steve.
1. A little clarification - by control unit do you mean ignition control? I'm assuming that's a different unit than the FI brain?
2. What's the AFM? (Air Flow Mass vs. Mass Air Flow sensor?)
Have to check my book to see if my OB even has these...
3. Fuel filter is only 8k miles old.. hopefully o.k.
4. Distributor cab is tight and seated correctly. (checked this)
Thanks for the continuing help!
-Brian
1. A little clarification - by control unit do you mean ignition control? I'm assuming that's a different unit than the FI brain?
2. What's the AFM? (Air Flow Mass vs. Mass Air Flow sensor?)
Have to check my book to see if my OB even has these...
3. Fuel filter is only 8k miles old.. hopefully o.k.
4. Distributor cab is tight and seated correctly. (checked this)
Thanks for the continuing help!
-Brian
User
Joined: Jul 2001
Posts: 3,291
Likes: 2
From: Midland, Texas
Brian,
Check archives under the search function at top of page.
Particular posts:
Shark Bog
Total power loss
87 S4 fuel delivery problem - too rich.
Under this last one I would try unplugging the MAS, MAF ...whatever ...if no difference while running... you found it! Or the O2 sensor.
Still could be coil/coil grounds. or the dreaded Vac leak. Arcing wires.....
There was a flurry of this problem last year but we seldom get the "Eureka ! I found the answer." back to the Forum ...please help change that.
There could be other posts under coil, low performance, limp home mode, sluggiush performance....in the archives and the Greg Nichols site. Should be pin out test values for the brain in here somewhere.
Good luck and let us know.
Check archives under the search function at top of page.
Particular posts:
Shark Bog
Total power loss
87 S4 fuel delivery problem - too rich.
Under this last one I would try unplugging the MAS, MAF ...whatever ...if no difference while running... you found it! Or the O2 sensor.
Still could be coil/coil grounds. or the dreaded Vac leak. Arcing wires.....
There was a flurry of this problem last year but we seldom get the "Eureka ! I found the answer." back to the Forum ...please help change that.
There could be other posts under coil, low performance, limp home mode, sluggiush performance....in the archives and the Greg Nichols site. Should be pin out test values for the brain in here somewhere.
Good luck and let us know.
Racer
Joined: Jan 2002
Posts: 329
Likes: 0
From: Colesville, MD
Brian,
I just replaced my coils last week after having the same symptoms you described....problems fixed. I don't remember if you have one coil or two but you can swing by on the way back to Jersey and pick mine up to try, maybe it will help narrow down the possibilities, I also changed my plug wires and still have the old set that you can have.
I just replaced my coils last week after having the same symptoms you described....problems fixed. I don't remember if you have one coil or two but you can swing by on the way back to Jersey and pick mine up to try, maybe it will help narrow down the possibilities, I also changed my plug wires and still have the old set that you can have.
Banned
Joined: Feb 2002
Posts: 5,248
Likes: 5
From: Ft. Lauderdale FLORIDA
Brian-
I recently had NO END of trouble trying to get my CIS injected '80 Jetta from Miami to Orlando. It did the EXACT same things you are describing, with the exception that the problem happened gradually over 100 miles. I couldn't get more than 40 mph at the end either-
I posted here (K-Jetronic Problem, around July 15th) and the general consensus was either coil or fuel pump. To cover bases, and since both parts were cheap... I replaced both items and the little car runs like a champ now..
(Of course you can hear it in the next county due to a separated down pipe, but that's in the works-)
To make a long story short, when I pulled the two parts I tested them and discovered that the pump worked fine but that the coil was TOAST. Turns out that coils overheat and short out in time. Try changing them first-
Normy!
'85 S2 5 Speed
I recently had NO END of trouble trying to get my CIS injected '80 Jetta from Miami to Orlando. It did the EXACT same things you are describing, with the exception that the problem happened gradually over 100 miles. I couldn't get more than 40 mph at the end either-
I posted here (K-Jetronic Problem, around July 15th) and the general consensus was either coil or fuel pump. To cover bases, and since both parts were cheap... I replaced both items and the little car runs like a champ now..
(Of course you can hear it in the next county due to a separated down pipe, but that's in the works-)
To make a long story short, when I pulled the two parts I tested them and discovered that the pump worked fine but that the coil was TOAST. Turns out that coils overheat and short out in time. Try changing them first-
Normy!
'85 S2 5 Speed
Racer
Joined: Jan 2002
Posts: 329
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From: Colesville, MD
Normy, you reminded me of another good point, I installed the fuel rail mounted pressure gauge which was an excellent tool in eliminating the fuel pump/ relay as being the problem, it won't help in as far as lettng you know if the injectors are firing correctly, but it does help.
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Three Wheelin'
Joined: May 2001
Posts: 1,641
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From: Hudson Valley NY
By AFM I mean AFC, airflow sensor the load input for the engine. Remove and reinstall the AFC relay #XVI (928 615 119 00) to clean the terminals, no other relay on the board is the same.
You said you smell fuel, which will lead me to believe; the fuel injector controller is working. You can check the pulse voltage of each injector; with the engine running at idle, remove the injector terminal and measures the voltage. The pulse voltage should be consistent for all injector.
Check each injector resistance, engine off, 2.5 OHMS
IF YOU CAN BORROW AN AFC AND COIL IT MY HELP YOU.
BE VERY CARFULL WHEN WORKING WITH VOLTAGE.
<img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />
You said you smell fuel, which will lead me to believe; the fuel injector controller is working. You can check the pulse voltage of each injector; with the engine running at idle, remove the injector terminal and measures the voltage. The pulse voltage should be consistent for all injector.
Check each injector resistance, engine off, 2.5 OHMS
IF YOU CAN BORROW AN AFC AND COIL IT MY HELP YOU.
BE VERY CARFULL WHEN WORKING WITH VOLTAGE.
<img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />
Thread Starter
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Joined: Jun 2001
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From: Arlington, VA
Thanks everybody for the replies!
The more I think about it, the more I think it's probably the coil. The sudden-ness with which it happened (it literally was just like flipping a switch... turning off the ignition or something) makes me believe that perhaps the coil burned out. This would (I think?) reasonably explain the "drop" in max rpms, too, as the coil burns out more and more. I had a look at my records last night and re-confirmed that just prior to my purchasing the car (8,000 mi. ago) the car had a new fuel distributor and new fuel filter installed, and had the fuel sender thoroughly cleaned. The spark plugs were also replaced at that time. The coil, I think, may be the original... 22+ years... seems like the most likely failure point. The fact that the fuel pump runs to start the car, and seems be "flooding" the engine out when I give it more gas also seems to point to adequate fuel delivery (although nothing is for sure!).
I'm probably going to take Eric up on his offer of a test coil/wires and see where that gets me. Updates to follow!!
Thanks again to all who replied!! <img src="graemlins/xyxwave.gif" border="0" alt="[bigbye]" />
-Brian
1980 928S 5sp. Euro
Silbermetallic/Blau
Temporarily Kaput!!
The more I think about it, the more I think it's probably the coil. The sudden-ness with which it happened (it literally was just like flipping a switch... turning off the ignition or something) makes me believe that perhaps the coil burned out. This would (I think?) reasonably explain the "drop" in max rpms, too, as the coil burns out more and more. I had a look at my records last night and re-confirmed that just prior to my purchasing the car (8,000 mi. ago) the car had a new fuel distributor and new fuel filter installed, and had the fuel sender thoroughly cleaned. The spark plugs were also replaced at that time. The coil, I think, may be the original... 22+ years... seems like the most likely failure point. The fact that the fuel pump runs to start the car, and seems be "flooding" the engine out when I give it more gas also seems to point to adequate fuel delivery (although nothing is for sure!).
I'm probably going to take Eric up on his offer of a test coil/wires and see where that gets me. Updates to follow!!
Thanks again to all who replied!! <img src="graemlins/xyxwave.gif" border="0" alt="[bigbye]" />
-Brian
1980 928S 5sp. Euro
Silbermetallic/Blau
Temporarily Kaput!!
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Joined: Jun 2001
Posts: 71
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From: Arlington, VA
I am fairly sure that it's not an AFM problem... namely because (at least, to my knowledge... and the parts/tech ref book seems to concur) there is no AFM in the CIS setup. I believe that came with the introduction of the L-Jetronic systems in MY 1980 US spec. Correct me if I'm wrong? (I frequently am!)
-Brian
1980 928S 5sp. Euro
Silbermetallic/Blau
Temporarily Kaput!!
-Brian
1980 928S 5sp. Euro
Silbermetallic/Blau
Temporarily Kaput!!
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From: New Jersey
Brian,
You are right. No electronics on your Euro fuel injection.
I would check the fuel pressure. There is a screen in the fuel distributor that may be clogged.
I can send you a picture of the fuel distributor for location if you want. Just email me.
Good luck!
You are right. No electronics on your Euro fuel injection.
I would check the fuel pressure. There is a screen in the fuel distributor that may be clogged.
I can send you a picture of the fuel distributor for location if you want. Just email me.
Good luck!
Three Wheelin'
Joined: May 2001
Posts: 1,641
Likes: 0
From: Hudson Valley NY
yup, only US 1980 HAS L jetronic. <img src="graemlins/c.gif" border="0" alt="[ouch]" />
EURO HAS K jetronic (1980)
you are right.
<img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />
EURO HAS K jetronic (1980)
you are right.
<img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />
Three Wheelin'
Joined: May 2001
Posts: 1,641
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From: Hudson Valley NY
Hey, bob,
I cannot remember everything.
You’re selling an S4 for a 911, <img src="graemlins/roflmao.gif" border="0" alt="[hiha]" />
even after I fix reverse.
Do you still have the spare trans, if so I am interested in it? Work is busy as always. No time to work on my car. How are you doing at work, buy any more BMWs.
<img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />
I cannot remember everything.
You’re selling an S4 for a 911, <img src="graemlins/roflmao.gif" border="0" alt="[hiha]" />
even after I fix reverse.
Do you still have the spare trans, if so I am interested in it? Work is busy as always. No time to work on my car. How are you doing at work, buy any more BMWs.
<img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />