s4bill

I removed the bottom part of the air box. I assume that is what you call it. It exposes the dampers.

While I had access to the MAF, I decided that I should disconnect the wires to it and try starting to it see if it would start in limp mode. Of course something told me hey lets try starting it frist and confirm it wont start. Well I turned the key and it started and it ran. I punched the pedal a few times and it reved up. I cant say it was perfectly responsive but it didnt studder or choke.

I did charge the battery or top it off while I was working. Could the full battery make a difference. It wasnt having any problem turning the engine over. I just did it to make sure it was fresh for more cranking.
I am going to change or add that ground. Is there any suggestions on the ground wire? Where are the other grounds I should check?

Does the car need to be running to check for gas at the vacuum lines on the dampers?
Should I just check them now since I just had it running a few minutes ago?

928Myles

I got stuck in the middle of nowhere once with a battery that was on the way out. It would turn the engine over (and continued to do so for quite a while over a dozen or more attempts to start it) with no apparent problem.

It would seem that my s4 is quite sensitive to turnover speed and voltage before it will consider starting.

YMMV

Car should NOT be running while you check the dampers. If they are bad then you will get fuel leaking out and this has not been a pleasant combination for too many 928 (ex) owners.

You can also get a tube to stick on the vacuum port and suck and see if it holds vacuum (if you can't smell any fuel - you don't want to get a lungfull of fumes).

Myles

Courtshark

Just to be clear, did you disconnect then reconnect the MAF wire before starting? If so, could have been simply the wire was loose or not making a good connection.

+1 on not running the engine while checking the lines!

s4bill

'Just to be clear, did you disconnect then reconnect the MAF wire before starting? If so, could have been simply the wire was loose or not making a good connection.
"

I did not. I was going to and just before I attempted to disconnect, I decided to try to start it to confirm that it wouldnt start. It started so now I dont know what to do.

I drove it for the first time yesterday. I drove maybe a mile or 2 from my house and then drove it back.

I am considering having the MAF and EH tested. I am going to replace the ground wire as welll.

This is going to sound ignorant but I pull the vacuum lines and smell the vacuum line or the vacuum input on the damper or does it not really matter the smell will just be there when you disconnect it?

I have another problem in that the car bounces/shakes really bad with any kind of speed. I am assuming this is flat spots on tires? They have been sitting for years in one spot. They are literally brand new. Wel less than a thousand miles I would guess.

Fontana

How did you make out with this?

s4bill

I have been driving it since without issue. When it sits at a light for a while, it may behave a little differently, I can see the tach move it a little.

If I punch the gas, it will break the tires loose.

If I am rolling and punch the gas, it seems to take off fine.

It had flat spots on the tires from sitting and it was really bad. So bad, you couldnt get over 30 mph without the car bouncing. I deflated the rear tires so that they were the same as the front (i think 36 psi) and that seem to make a diference. We had 100 degree days so I took it on the hot days and ran it on the highway and the majority of the flat spot has disappeared.

I did notice that the other night when it was cooler (70's) a vibration returned. Not sure if it is from tires. I need to check it out this evening.

Charlie R

I've read a lot of these "starts and dies" threads. For my 81 928 it was a bad ECU. Plugged a know good one in and the car started and ran great.