89 300E, Idle, starting problems
 

Hello All,

I have read alot of threads regarding this and have checked alot of this out.
89 300E, 62K, regular service:
Car started hard, need to give it gas to keep it running. Then once I put it into gear it wants to stall. Once it was running, say a mile or so, car was fine. I started having this problem when my dumb head put 87 octane in it. Since then I have ran cleaner and 5 tanks of 93. Still was happening. So I checked the car out. New plugs, distributor and rotor, checked plug wires - fine. Then I noticed that the vacuum hose was pulled from the fuel regulator valve, hose that goes from rubber house of air cleaner housing to valve cover. Reconnected that. Now when I start the car it runs real rough, shaking at idle and at 3000 RPM for a minute then once I take off smooth. But when I come to a stop, it idles a little eratic, 500 - 700 rpm, almost like the AC is kicking in, but it is not. I then came home and checked the OVP. I unplugged it and started the car. Car Started the same as it did before when hot, but cold start I couldn't get it started. Plugged the OVP back in and the started cold and started but same as the above problem. I then notice that the CO adjust on top of the throttle body, the long aluminum column that goes up into the air cleaner housing, had some weird drill marks near the top. The housing itself has a crack in it. Does air come in this housing or is it just for the hex screw adjust. When I put a hex down it it pushes down on the butterfly but I can't seam to turn the screw. What size hex is this?
Anyway, it seams to get worse with the more days that go by. Definetly worse once I repluged in the vacuum to the fuel regulator.
Any suggestions will be appreciated. I will post the solution once I find it also. thanks

More: Violent, one time, shake on cold start is a product of a low idle. It never did it until I reconnected the fuel regulator valve vacuum hose yesterday. I have checked for vacuum leaks and when I spray starting fluid under the air cleaner cover it goes up in idle some and idles great for a minute then back to eratic. Is this due to the crack in in the CO adjust housing. Is this crack a source of vacuum leak? It seams I fixed one problem and really exposed another.
When the car stalls in D while driving and then stopping is a result of low idle. It drops to 600 RPM at a stop then will just shut down, like I turned the key off, no rough idle then stall. I simply double foot it and gently press the accelertor to maintain 600 RPM.
It starts easily but idles rough, need to flutter the accelerator to keep it going then brake and accelerate at the same time to put it into Drive or Reverse. Once rolling though, from 600 RMP and up, the car runs great.

RE: 89 300E, Idle, starting problems
 

One thing I noticed is that this morning I fueled up with 93 and some fuel injector cleaner and at lunch the car idled great around town, no stall. Was still a little rough at start.

Does fuel injector cleaner lean or richen?

RE: 89 300E, Idle, starting problems
 

If it is only a cold running problem, Check the fuse on your overvoltage protection relay, or your relay may be faulty or have a bad connection on one of its pins.

The best way to analyse this is to measure the current through the EHA and make sure that the current changes as the engine warms.

RE: 89 300E, Idle, starting problems
 

have you checked your idle air control valve? this was a problem for me in a different car. sounds exactly the same as what happened to mine.

RE: 89 300E, Idle, starting problems
 

where is the idle control valve i have the same problem on a 230TE .is this fitted with same systems?
thanks Steve

RE: 89 300E, Idle, starting problems
 

it sits under the air filter cover next to the valve cover.

RE: 89 300E, Idle, starting problems EUREKA
 

yES FINALLY GOT IT !! .I TOOK OFF AIR INTAKE AND LEFT ALL OTHER PIPES IN PLACE (I HAD TO PRISE OFF BREATHER TUBE FROM AIR PAN AS IT WAS VERY TIGHT .I HAD BEEN REMOVING THE LOT , when i did this It WOULD,NT RUN ON TICK OVER BECAUSE OF VACUUM IMPLICATIONS .When i start engine now minus air pan , it is ticking over and running perfectly ,the problem all along has been engine breathing heavily into air intake ,it must've been upsetting the mixture balance .the engine is using a little oil and has hi mileage .
Thanks for anyone that took an interest
Steve