Engine cut off

[somoney311]

All right gents, you have helped me plenty of times in the past. I have searched the forum for people who have had a similar problem to no avail. If there is a post or thread out there please let me know.
My problem...I have an 89 930 with a K27 turbo and aftermarker intercooler, heat exchangers, exhaust and such. The boost was set to 1.0-1.2 from the previous owner. I am looking to reset the boost to 0.8 for reliability until I get the chance to rebuild the engine and get it setup to run EFI. My problem is that when I give it full throttle, once the boost builds and "hits" the engine just cuts to idle. It will stay at idle for a few seconds even if I have the throttle to the floor. This does not have a specific pattern at what RPM it does it but the only constant I can see is when I give about 75% throttle or more and when the boost hits. I have had the engine cut out between 0.6 bar and 1.0 bar at various RPMs. If I am moderate with the throttle and let the boost build slowly I can get it to 0.8 bar with not much of an issue.

I am not that smart on these cars, or any car for that matter, because I have not messed around with them. I am looking for suggestions on what the problem is and how do I confirm it. I don't have an issue tearing into the car even though it is my daily driver. I just need to know what I am looking for and where it is located.

Thanks for the help,
James

[somoney311]

Here is a pic of the car for your enjoyment!

[Chuck.H]

Hi James -

I've seen this before -- your problem is definately those wheels. Once you get them off and sell them to me your turbo problems will disappear.

Seriously, "I haven't messed around with cars" and "I have no problem tearing into a (Porsche turbo) that's my daily driver" don't really belong in the same paragraph!

Chuck.H
'89 TurboLookTarga, 359k miles

[Cooper911SC]

Hi James, just a freebie Bump as I'm interested in a real answer.

Hope you get it sorted.

Cooper

[Winter]

James, shooting in the dark here as I have no experience with a 930. However, I'm a turbo charged Audi veteran, having owned a few different ones and wrenched on all of them, I experienced very similar issues with a S6 avant. It was a boost leak. Ended up being very easy to track down when the boost hose finally failed catastrophically! Hahahaha!

First thing I'd do is check all the hoses in your system, very thoroughly, can't hurt and will be a start. Check all clamps as well, as some might be just loose enough to leak when you get on it, but won't when you're being easy on the throttle. Hoses too, a minor split may hold boost under mellow acceleration but then leak when you get after it.

Good luck!

[somoney311]

That sounds like a solid start. I will look into the hoses this weekend. Thanks for the input.

James

[somoney311]

Chuck.H you are right they shouldn't be in the same paragraph. The mechanicals in any engine shouldn't be that difficult especially pre EFI and sophisticated computer management. As for the electrical issues if they come up....leave that to my dad who is an electrical engineer.

James

[somoney311]

Well I looked into the hoses and I didn't see anything out of place (that I noticed). I also replaced the overboost switch with one that I had as a spare. I still have the same issue. I was able to get the boost upto 1.1 in fourth gear but as I slowly rolled on the throttle the engine just cut to idle.???

[jakz]

Great looking car i hope you find the answer soon!