onthedge928s4

i just had my 88 928s4 in for a water pump t belt cam seals ect.runs rough ,especially at 1500 and 2200 rpm and exhuast note sounds bad not clean yuo can feel the shak in the gas pedal more but it definitely sounds bad.the shop had the car for 2 months and stil is fumbling around with it .i`m currently having the wires repl. too maybe that will help?????????have any ideasor techs in nj that can help . i`am a cert. bmw tech...

Thom1

Hi Bob,

Leaky intake syndrome can cause rough idle. Brittle hoses could have cracked. Old rubber vacuum elbows may not seal. See Greg Nichol's page for vacuum check procedures. One involves old intertube with valve piece to pressurize the intake.

HTH

Steve Cattaneo

Start by checking the timing, crank at TDC number 1 piston up on compression stroke, now check the cam timing marks. You don’t have to remove the covers. Remove the air intake hoses you can see the cam timing marks through the air holes that are in the cover. Make sure all marks are properly aligned. Now check to see that the distributor rotor just starts to point to the number 1 ignition wire
You will need work shop manuals

good luck
Steve c

John.

Always start with the basics.......compression, spark, fuel, timing, etc. I had a similar experience, and as it turns out I had a loose injector connector......solved the entire problem instantly. I'd be willing to bet that whoever did the work probably knocked something simple loose......hard part will be finding it.

Randy V

Vacuum leak - the #1 suspect on the 928.

Sometimes hard to find, usually cheap and easy to fix.

Start at the brake booster vacuum source and work outwards from there.

Kaz

Bob, what shop has been fumbling around with your car out there?


K

Tabor

Take it back to the shop. Make them fix it.

Steve Cattaneo

Also ck. the firing order

Steve C