Dylan_928

My 89 S4 auto has an issue where when you go to start it it will crank and crank and crank before sounding like it wants to start. I thought maybe it was the fuel pump check valve and today i changed it and it was not the issue. It has new injectors, new battery. I know i have injector pulse. Not sure about how much fuel pressure i have. Also, the longer it sits the harder it starts and longer it takes to start.

Mrmerlin

based on info you could have a leaking injector or failing damper or FPR.

pull the vacuum line off the front damper smell it for gas if you smell fuel then you should replace both dampers and the FPR

If not swap in your old injectors

Dylan_928

i will try that tomorrow morning! Thanks

Dylan_928

the two in the rear of the engine bay are leaking. Cant remember which these ones are. Also, what cite or vendor has the best price on these? I have looked around and cannot tell if the parts are legit and if they are actually for my year.

jej3

928Specialists (http://www.928gt.com) or 928sRus (http://www.928srus.com) for New
928Intl (http://www.928intl.com) for Used but warranted

They are pricey these days.

Mrmerlin

http://www.928srus.com

Dylan_928

so the one In the front is a damper, the one in the rear passenger is a regulator, and the driver side rear is also a damper?

Mrmerlin

yes thats correct for an S4

Tails

I recently had problems with starting and running my 1990 S4 after a total air intake manifold overhaul and painting with Porsche specification paint. All ignition wiring was checked for continuity and resistance, knock sensors renewed, the idle stop valve was overhauled as best a possible (WD 40, "instant technician"), injectors overhauled and tested for delivery quantity, distributer caps checked and cleaned, new spark plugs fitted , LH computer checked out by fitting a spare, In searching for the problem, ignition circuit fully checked for continuity and resistance etc, etc by fitting alternate S4 componants. After all this the car still had problems starting and running . Intake manifold was again removed and checked and reassembled, problem still persisted. After hours of investigation it was found that the rubber hose from the idle stop valve that connects to the engine oil filling body was not connect correctly allowing excess air into the air/fuel mixture.
Reconnected hose and the engine now fired

up immediately. It was also noted that the car performance had also improved and is a real pleasure to drive.