Hi-
I just purchased an '89 560SEC and am having a very difficult time determining what is wrong with the idle & running of the engine. The car does not appear to have any enrichment when first started, but acts like more than one injector is running wide open. When it is first started, cold, it will stall unless you give it enough gas (1000rpm or more. After about 30 seconds you can let it try to find idle, but it hunts between ~500rpm and ~800-900rpm. The exhaust is VERY rich (it stinks with fuel). I bought the car with a broken (litterly, front vacuum tube)fuel pressure regulator and the idle was erractic and bumped up to 1000 rpm with the throttle linkage (the one link down under the front of the throttle body, just behind the cruise linkage. It would still stall and hunt up to 1000rpm. I replaced the fuel pressure regulator.....no change! So I replaced the Idle control valve....no change! I seems to have a severe miss....running on seven, but it does that above idle too. The miss is it running very 'rich'. I replaced the distributor cap and rotor and the plug wires thinking it was an electrical miss.....no change. It appears just to be a very rich condition....all the time. It will not idle, just hunts 500 to ~900 rpm and often stalls. After stopping, it is very hard to start...like leaking injectors.
I am thinking this rich condition is controlled by some electronics, rather than a faulty injector....it just runs too rich.
Could someone guide me through the logical troubleshooting steps to get to the bottome of this problem?
Thanks for all your help...in advance.
Rick
'89 560SEC
'88 300CE
07-17-2007, 03:37 PM
Linear Mode
