Stumped the 84 928

More
19 Dec 2011 22:25 #7421 by lrpman
Stumped the 84 928 was created by lrpman
Ran PERFECT all day, stopped at a store then NO START, kicked once then spun over but no start. I
1. Checked the fuel pump and fuel tank, tank at 1/2 and pump hum when key turned to start (Tried, no start)
2. Checked for spark ZAP! do not ask (tried no start)
3. Pulled the air cleaner (K&N) no problem there. (Tried No start)
4. Called AAA for a tow, and then threatened the car with a trip to the scrap yard.
Turned key and it started.
What the heck is it? I FIXED nothing, did the normal, air, spark, fuel and NOTHING then it starts.

Please Log in or Create an account to join the conversation.

More
19 Dec 2011 23:40 #7423 by 928mac
Replied by 928mac on topic Stumped the 84 928
Well sometimes a coil will act like this and start working once it cools off, but you said it had spark, so its not that.

The ignition switch has been know to cause problems but you say you are getting fuel and spark. You need to verify fuel pressure.

it could be the MAF sensor
it could be the LH ECU

we need more details

Please Log in or Create an account to join the conversation.

More
20 Dec 2011 10:51 #7426 by lrpman
Replied by lrpman on topic Stumped the 84 928

Well sometimes a coil will act like this and start working once it cools off, but you said it had spark, so its not that.

The ignition switch has been know to cause problems but you say you are getting fuel and spark. You need to verify fuel pressure.

it could be the MAF sensor
it could be the LH ECU

we need more details

That is NEW not a rebuild
BOTH ECU's where replaced with Factory New when I had the shake problem and a rough idle.
The COIL is a GOOD thought, yes it sparked BUT did it every time I hit the key?
The coil is NOT a Bosch, it is from the speed shop side, back up for the modified. It was NEW in the box 12 volt 80,000 volt Accell. MAYBE that IS the problem, can order a new one and have Santa drop it off next to the new Sig Sauer.

Please Log in or Create an account to join the conversation.

More
20 Dec 2011 11:06 #7427 by 928mac
Replied by 928mac on topic Stumped the 84 928

That is NEW not a rebuild
BOTH ECU's where replaced with Factory New when I had the shake problem and a rough idle.
The COIL is a GOOD thought, yes it sparked BUT did it every time I hit the key?
The coil is NOT a Bosch, it is from the speed shop side, back up for the modified. It was NEW in the box 12 volt 80,000 volt Accell. MAYBE that IS the problem, can order a new one and have Santa drop it off next to the new Sig Sauer.



I am not sure George. I have heard that only the original coils work well but I am not sure if it is a resistance issue or what.
I would not replace it just yet as it is nice to leave everything as is and find that actual problem. if you start replacing things it may fool you and decide to work for another month and then fail at a very inopportune time.

Grounds are a big intermitant issue on these cars. if you have a meter to check some of the grounds at the ECU, look for anything higher then 0.3 ohms. 0.5 is starting to go bad.
Also, if it dose it again, wiggle the key in the ignition switch to make sure that the switch is not starting to fail.
ILL search the coil issue on Rennlist.

Please Log in or Create an account to join the conversation.

More
20 Dec 2011 15:56 #7431 by 928mac
Replied by 928mac on topic Stumped the 84 928
All I have found is that a coil either quits or starts to break down and miss fire at high rpm. (not your problem)

The other thing I found is that they say our system is a matched ignition system and it is already great quality that will not benifit from an aftermarket coil other then the bling.

So lets look somewhere else.

Dose it start now?

Please Log in or Create an account to join the conversation.

More
21 Dec 2011 22:04 #7462 by Kiln_Red
Replied by Kiln_Red on topic Stumped the 84 928
Brad, his car has the "air-flow controlled" L-Jet fuel injection brain. It has an air flow meter, rather than an MAF.

George, follow Brad's suggestion on checking and cleaning your grounds. Also, if the sudden no-start issue arises again... Listen to see if the fuel pump is still being energized when you disengage the starter. Try to isolate what circuit(s) are impacted when your car does this. Intermittent issues are the hardest to diagnose and fix. It is hard to fix something that is only sometimes broke. :rolleyes:

It may be as simple as your fuel pump fuse, #13 I believe, making an intermittent contact. Then again, it could be the "green wire" creating an intermittent spark.

Please Log in or Create an account to join the conversation.

More
21 Dec 2011 22:42 #7464 by 928mac
Replied by 928mac on topic Stumped the 84 928
Thanks for clearing this up Austin. Since I only own a S4 I forget about the early fuel injection.

Austin is right about the intermittent issues and check that green wire all the way along from the distributor to where it disappears. I have heard a lot about it but my car dose not have it.

Please Log in or Create an account to join the conversation.

More
22 Dec 2011 08:34 #7468 by lrpman
Replied by lrpman on topic Stumped the 84 928
Thanks guys, I drove it when I got back from Texas and it drove fine, started as normal, ran as normal. I might just park it in the shop so I can go over all the grounds again.
I was picking what is remaing of my brain and came up with what happened when it did not start.
1. Turned key car ran for a split second then stopped.
2. Immediate try got NOTHING
3. Wait about 2 or 3 min again a cough but no start.
4. Ran all the test I could
5. Called AAA
6. Got ready to give it up to parts car status
7. Car started and ran fine and still does.
Observation
1. Air was about 72 deg
2. Dry, no rain
3. Ran at 75+ mph on interstate for about 30 min before arriving at FedEx
4. In FedEx for about 15 min
5. No Start

Please Log in or Create an account to join the conversation.

More
22 Dec 2011 08:38 #7469 by srshaw3
Replied by srshaw3 on topic Stumped the 84 928
Is it an auto?
Isn't there a relay in the auto that can cause such issues?
If an auto perhaps related to not knowing it is in Park...

Please Log in or Create an account to join the conversation.

More
22 Dec 2011 14:02 #7474 by 928mac

Please Log in or Create an account to join the conversation.

More
22 Dec 2011 21:56 #7486 by lrpman
Replied by lrpman on topic Stumped the 84 928

Is it an auto?
Isn't there a relay in the auto that can cause such issues?
If an auto perhaps related to not knowing it is in Park...


That is the problem with the 1982 about Park, yes both are Automatic. The 1982 needed the shifter adjusted to trip the cut out switch which I did and it is fine. The 1984 is fine the starter spins over and it would NOT if the cut out was not tripped.
Cut out is the Neutral Safety Switch

Please Log in or Create an account to join the conversation.

More
23 Dec 2011 03:05 #7490 by srshaw3
Replied by srshaw3 on topic Stumped the 84 928
Sorry, I jumped over that it was cranking.
The green wire is a good option to check, it runs from the control unit near the jump post on the passenger side across the front of the motor to the distributor (as I recall). It could be grounding, but as I recall, it can have an internal breakdown as well.

Greg's site also suggests the ignition switch: nichols.nu/tip484.htm

Please Log in or Create an account to join the conversation.

More
24 Dec 2011 22:50 #7506 by Kiln_Red
Replied by Kiln_Red on topic Stumped the 84 928
I would replace the ignition switch right away. It is cheap enough to do as preventive maintenance if nothing else. Actually, that is very likely the problem that George has here.

Please Log in or Create an account to join the conversation.

More
26 Dec 2011 21:59 #7522 by lrpman
Replied by lrpman on topic Stumped the 84 928

I would replace the ignition switch right away. It is cheap enough to do as preventive maintenance if nothing else. Actually, that is very likely the problem that George has here.

Did the swap out with the KNOWN good one out of a parts car when this happened the first time.
I spoke to Porsche Guru and his GUESS is the coil since it is ab Acell from the race car not a Bosch. They said that the resistance IN the coil would cause the overheat of the coil and the no start then when cooled it would work again. Same as you folks so I am going the coil route and get a new one for the car.
NOW this is a 1984 they stated that i MUST get a 1984 NOT a 1982 since it is different and will have the same problem after some time. ANY input on that statement?

Please Log in or Create an account to join the conversation.

More
26 Dec 2011 23:21 #7523 by 928mac
Replied by 928mac on topic Stumped the 84 928
I do not know George what the difference in the year coils are.
I am not sure the cost either. I do not use mine any more and if you are in a bind and my 89 coils would work, I would send them for the cost of the shipping. I am not trying to get rid of them though.

Brad

Please Log in or Create an account to join the conversation.

More
27 Dec 2011 00:38 #7524 by srshaw3
Replied by srshaw3 on topic Stumped the 84 928

NOW this is a 1984 they stated that i MUST get a 1984 NOT a 1982 since it is different and will have the same problem after some time. ANY input on that statement?


I would lose credibility in them for that statement;
928inlt.com and 928gt.com lists the same ignition coil for '78-'84

Please Log in or Create an account to join the conversation.

More
28 Dec 2011 22:15 #7543 by lrpman
Replied by lrpman on topic Stumped the 84 928

I would lose credibility in them for that statement;
928inlt.com and 928gt.com lists the same ignition coil for '78-'84


The problem is that most people are a guru when you have a problem but no idea any other time.
Same people I asked about the engine shake at 1,500 rpm and said that it was a BROKEN mount on the engine. No it was not since they where all NEW when I BROKE one working on the car.
Coil will be in on Friday so I will try that.
Been driving the Blue one, 1982, and it runs better than the 1984 and if someone does not buy the darn thing I might just park it at the land and keep it.

Please Log in or Create an account to join the conversation.

More
29 Dec 2011 12:22 #7544 by pcar928fan
Replied by pcar928fan on topic Stumped the 84 928
George, if I was more stable in my job and financial situation I'd buy that '82 and have it for friends when they need to borrow a car, or for those 928 ex-pats who hope to get back in to one someday...

I'd do a "Leeroy" deal where you get the car for a year, but have to keep insurance and registration on it the whole time and you have to take care of anything that breaks and you have to do ONE NICE thing for the car to make it better...

Your cars sounds like the PERFECT candidate for that! We just need some benevolent folks to step up and DO IT! My '81 is already being used by a friend in that same kind of role actually, so I guess I am already doing it, but am doing so with a car I value at $10k! Need to get your car and get my '81 back! LOL! I should have my head examined!

James
78 Silver / Black-white #295
84 Ruby Red / Black AO84
88 Dark Blue / Linen-Black
92 Polar Silver / Dark Blue 92EURO
93 Arrow Blue / Black

Please Log in or Create an account to join the conversation.

More
29 Dec 2011 19:41 #7547 by the flying scotsman
PET lists 5 different coils for the 84 model year depending on engine type.

If the car in question has one coil then its the same coil 80-84 model years that I checked. 928 602 503 00

The 84 model year with twin distributors have 2 coils and are different part number 944 602 115 00

I'd also try new Bosch coil(s) to start and also check the fuel presuure. My fuel pump failed but allowed a restart after towing..........I replaced it.

An ignition coil can be tested with a special tester that operates the coil sparking a spark plug simulating working conditions except engine load.

Please Log in or Create an account to join the conversation.

More
29 Dec 2011 23:24 #7548 by lrpman
Replied by lrpman on topic Stumped the 84 928

PET lists 5 different coils for the 84 model year depending on engine type.

If the car in question has one coil then its the same coil 80-84 model years that I checked. 928 602 503 00

The 84 model year with twin distributors have 2 coils and are different part number 944 602 115 00

I'd also try new Bosch coil(s) to start and also check the fuel presuure. My fuel pump failed but allowed a restart after towing..........I replaced it.

An ignition coil can be tested with a special tester that operates the coil sparking a spark plug simulating working conditions except engine load.


The 1984 is a Single Coil Car and after talking to Brian Redman down in Florida I think I understand what the deal is with the coils. The Bosch Coil can stand more heat than the Accell which was for a CUSTOM type of application the race coil we use on the Modified is design for extreme use but the one in the 928 is of lesser quality than the one we use. ALSO the one in the 928 was $45.00 the one in the race car was $125.00. we will get teh new coil Today (Friday) so will install and the ROAD TRIP!

Please Log in or Create an account to join the conversation.

More
30 Dec 2011 21:41 #7549 by lrpman
Replied by lrpman on topic Stumped the 84 928
IT WAS THE COIL!!! I think 125 miles and NO problem at all.

Please Log in or Create an account to join the conversation.

More
30 Dec 2011 22:24 #7550 by 928mac
Replied by 928mac on topic Stumped the 84 928
Hmmm post #2, I was right and didn't know it

Please Log in or Create an account to join the conversation.

More
31 Dec 2011 07:45 #7551 by lrpman
Replied by lrpman on topic Stumped the 84 928

Hmmm post #2, I was right and didn't know it


Looks like it was, will drive the car more and see. Thanks for all the input since I had the mind set that the coil was NEW so how could that be the problem. Simple WRONG COIL.

Please Log in or Create an account to join the conversation.

More
31 Dec 2011 10:43 #7553 by Kiln_Red
Replied by Kiln_Red on topic Stumped the 84 928
Excellent news, George! I'm glad you got it resolved. Now go enjoy your car. :D

Please Log in or Create an account to join the conversation.

More
31 Dec 2011 15:34 #7554 by the flying scotsman
By George.........I think you've got it!!!

Please Log in or Create an account to join the conversation.

More
31 Dec 2011 17:57 #7555 by lrpman
Replied by lrpman on topic Stumped the 84 928
Drove the car AGAIN today and it is spot on. Still have the 1,500 RPM shutter BUT that is the Drive shaft mount that is NOT in perfect alignment.
Starting, High RPM the engine is correct now.
Anybody know a GOOD alignment shop in the Aiken S.C. area that is not AFRAID of a 928? If nothing in S.C. will load up and take it to Brumos in Jacksonville. Gee I miss Bob Snodgrass was a good friend and fellow collector.

Please Log in or Create an account to join the conversation.

Moderators: Rich928mm928billvvOC

Don't have an account yet? Register Now!