Don Carter

Ken,

When you say "recovers nicely" you mean after reving?

I have a Blink'r but haven't used it in a few years.

I'll try doing some adjusting.

bill928p

Well I have a similar problem with my 928 1988 S4 Automatic.
This is a car that has not been driven in about a year. I am putting it back in service. Put in a new battery cleaned the connections. The car starts right up revs good and can be driven. Here is my problem. The engine will run until it gets warm and then it quits like you turned off the ignition and won't restart. When it cools off overnight the same thing happens, starts great, runs perfect for 12 minutes ant then cuts off. When I try and restart it acts like it is out of fuel and there is a clicking noise under the center of the intake manifold. it sounds like an electric fuel pump running dry.

Anybody got any ideas! This car has never done this!

Don Carter

Clicking injectors is a sign of computer failure, but I didn't think that was an intermittent issue. Has the computer ever been replaced/rebuilt? You might want to start a new thread for your issue with all the details.

dfw56

Good evening In my case I can't rule out the new porken chips. I changed back to the original chips and it did the same thing. Based on responses and input from others. It appears my issue is either in the ce board or the solder points in the lh or ezf computers. The solder points look fine. But so did the solder points in my cruise control unit and after reflowing them it came back to life and works fine. What I don't have is a known good lh and ezf to test vs. what I have. Thanks for the thoughts on this subject David

76FJ55

I've been dealing with a similar issue on my 85. It would randomly cut out/shut off but I could usually get it going again by jumping one or both the LH and EZF relays, though it seemed to be getting worse. On occasion I would get the fast clicking fuel injectors with the key in the run position with engine stopped. I've also experienced the random fluctuating of the charge gage with the ignition in the run position and the engine stopped.

Over the weekend I was having issues again and managed to get it going by jumping the relays, and made it home, however I had been unable to get it to restart. In troubleshooting it seemed like everything at the CE panel was working correctly, so I decided to recheck the grounds at MP VIII, again. I have cleaned them previously a couple years ago, but wanted to reevaluate them. There are actually 2 ground points for MP VIII, one on the right (passenger’s) head and one on the left (driver’s) head. What I discovered is that the right ground point has the 6 wire ring terminal (located at B-65 in the wire diagram) and that this is s crimped and soldered ring terminal. The left head MP VIII ground point has the 2 wire ring terminal (located at D-61 in the wire diagram). This ring terminal is only crimped and NOT soldered. this 2 ring terminal is the ground point for the LH and the O2 sensor. I cleaned and soldered the crimp connection and reattached it to the head. I also replaced the plastic connector housing on the end of the CPS as it was beginning to crumble, but don’t thing this was related to my running issues. I can’t say with any certainty that my problem is permanently fixed as it has been intermittent, but the car started upon reassembly and that gives me hope. I haven’t taken it for a drive yet, so i'll have to follow up on how it does later.

ROG100

Simon any update?

dfw56

Thank you Simon. I will be checking that area this weekend! One of the differences though almost EVERY time mine cuts out I can always start it back up. When it hasn't 5minutes or less and it starts and will idled and run till I shut it off. That being said when I did the timing belt the smog pump and all the associated hardware some how fell off! . So i was in the area with wrenchs etc. One of the advantages to living out here on the vast prairie no smog rules. It can get damn windy though. Again thank you for your input David

dfw56

Simon or Roger. I just looked up on my ground point diagram. MP Viii I have never seen those grounds when working So I need a little better description on the locations I've never seen the ones on the shock towers either. Maybe I need better bifocals first! Thanks

MainePorsche

I have a later MY, but I did have these images in my files.

76FJ55

Small update, nothing definitive yet, as it could go weeks between episodes. Took it for a short drive and it didn’t shut down on me, but don’t know that I am absolutely convinced it has been cured. Started and ran without incident, but I will need to give it more time.

Don’t have a good picture of MP VIII, so below is a page from the parts catalog for the fuel system. The two locations for ground point MP VIII are where Item 17 and 9 are bolted to the heads. 17 is bolted to the right head and 9 the left. You will need to remove the air box to access them.

MainePorsche

Simon,
From your initial post re MP VIII, it sounded like you were referring the the bellhouse grounds deep under the airbox. As I am not that familiar with pre S4 cars, I was a bit perplexed when I posted the OB ground point pics for the OP. Below is a pic of MP VIII and MP IX on the S4. These ground points are the two bolts which hold the throttle wheel bracket to the block. Probably similar to the bolts that hold the brackets you referred to.

dfw56

Thanks for the help finding those grounds. I've been in that area many many times and never realized those were grounds. I'll be cleaning them up this weekend and we'll see what happens. Thank You everyone. David

76FJ55

Yes those are the grounds I was referring to. I mistakenly referenced them being attached to the heads, when they are actually attached to the block. On the 85-86 there is no throttle wheel and the fuel pressure regulator is mounted in that location, but the ground points are the same. Also on the 85-86 cars both locations are referenced as MP VIII. The 6 wire (factory soldered) terminal is located on the lower bolt in the picture (labeled MP IX) and the 2 wire unsoldered connection is located at the upper bolt (labeled MP VIII).

dfw56

I must have looked at those wires 50 times over the last 9 years and never made the connection they were the grounds being referred to in diagrams. I was all over that area during the timing belt smog removal fuel pressure regulator replacement work last spring. I'll jump back in it in the next few days. In the mean time I better keep my day job! We'll see how it turns out. Or I could limit my trips to 20miles. Which is when the issue starts Thanks everyone. David

76FJ55

Well, a little update. Took the car for a short drive this evening. The problem has reemerged. So my final solution did not lie in the MP VIII ground points. Got a couple miles from the house and it shut down on me. Cranked a few times and it restarted. On the initial attempts it seemed like it was trying to start but the tack was just bouncing wildly and it wouldn’t quite catch. After several tries it fired up and was running normally. Got a couple blocks from the house and it shut down again. This time I noticed I could here the fast clicking injectors. Turned the key off and on a few ties but every time I turned it to the run position I could hear the injectors clicking. I then pulled and jumped the EZF relay and then when I turned the key on the injectors where silent. I tried restarting but it wouldn’t quite catch would stay running for a fraction but was coughing and popping and then would shut down. I then removed the LH relay and jumped it along with the EZF and the car restarted and made it the last few blocks to the house.
So I don’t seem any closer to a solution than before. Will keep trying and let you know what I find if I make any more headway.

If anyone has any ideas on what to try next I’m open.