disconnecting EGR improves cold idle?
 

:confused:

I have been trying to track down a cold idling problem (car starts easily then idles very badly and sometimes stalls. no problem once engine warm).

I disconnected the EGR valve and it seems to cure the stalling problem even though the idle is still not smooth.

Any ideas what my problem is or what i should try next?

Keith

The EGR valve is supposed to be closed at idle, so disconnecting it should not affect the idle. However, if the EGR valve is leaking, it will make your engine run worse throughout the RPM range, especially when cold.

If the problem only presents itself when cold, you may have one or more bad glowplugs. Do a search to see how to check them. This may not be the case since the car starts easily, but it would be good to eliminate the possibility. Also, when were your valves adjusted last?

glow plugs fine - no idea on valves
 

glow plugs are definitely ok (as you say it fires perfectly an there are no warning lights misbehaving).

valve adjustment - possibly never, at least not in last 5 years, how often would you suggest is required? I assume (from distant past experience) this requires head off :rolleyes:

K

valves - what adjustment?
 

Hang on a minute

the valves are hydraulic is it possible to adjust them? :confused:

they dont rattle or sound anything other than silky smooth so i am not sure that is consistant with badly adjusted valves anyway or am i completely off track here :cool:

K

If your car is a 96 then it has hydraulic valves and that is probably not the issue.

When were the glow plugs last replaced?

When did you last change your fuel filters?

Yeah, I was just assuming without even thinking. I've got OM617 on the brain! On the older engines valve adjustment is recommended every 10,000 miles by the factory. Some say to wait as long as 20 or 30 thousand, though. In any case, if your valves are adjustable, it's definitely overdue. When troubleshooting driveability issues, always make sure that all routine maintenance is up to date (ie, valves adjusted, fuel filters...).

not glows or fuel filter
 

it definitely not glows, since starting is no problem initially its the idling thats the prob, also no warning light misbehaviour which has always been the case whenever I lost a glow, not to mention harder starting.

fuel filter, has been changed on service interval religiously.

I gues from your questions you guys are doubting my idea that its EGR related?

Keith

What you should try next is to post the year and model of your vehicle so that we are not left guessing and putting up innacurate information. ;)

my vehicle
 

Brian
thanks for pointing that out , I had thought it was on my signature but on checking it wasnt , my mistake. hope you can see it now.

That's much better.

Now you can toss all the previous responses in the trash because none of them are related to the issues you have with the 606 engine.

I won't provide any advice on the 606 either, because I don't own one.

Hopefully, one of the members who have some experience with the issues of this engine will provide you with some input.

I might suggest that you delete the entire thread and start a new thread with "606" in the title, together with "rough idle".

I have cleaned the MAF wires with a gentle spray of say electric cleaner or brake cleaner and it has changed the idle quality.

maybe you idle speed is set too low, not that i know how to change it, but i had an outboard motor that did that, just needed more fuel at idle.