engine surge, miss
 

Hello, i have a 96 300 with 116,000 miles, car runs great except miss when engine is cold , goes away after 2 minutes of slow driving, and at around 2000rpm engine has surge except when cruisr control is on. Now that sais i also get a check engine light when i put cruise on and if i dont use cruise for about 5 engine cycles light goes off. it is not throwing a code to the obd11 as i have a code reader. car runs great on cruise no problems like i sais cruise gets rid of engine stumble. could it be cruise amp? does this car have one? Would that cause stumble at 2000rpm?
thanks for any insight.

Probably 3 different issues at play: check GP's at relay concerning initial stumble when cold, check resonnance and egr flaps for 2k rpm surge and have system scanned with SDS for cruize probelm as may be a bad speed sensor or abs issue.

Sounds like the classic problem with the Flapper valves in the intake manifold. The oil mixes with the soot and causes the butterfly flapper valves to stick (Resonance Valves)... Relatively easy to fix on the non turbo. Also if you eliminate the EGR then you shouldn't have the problem again. Oh course with the cleaner diesel there may be much less build up in the intake. I'm sure that is the problem your seeing, yet on mine I don't remember if the Cruise control made a difference. Yeah the Miss sounds like a glow plug or even leaking injector..

okay where are the resonce flapper(s).
thats the one right by the air filter?
it works fine at idle but at 2000rpm it opens and closes.
as for the egr it works open and closes and was replaced 30 k ago.
how do you bypass? i read on this forum there is no way to remove as the computer will look for it.
How do you test the glow plug relay?
could all these problems be related?
thanks for help.

Resonance flap is between the air cleaner and crossover, egr is at the IM where the other end of the crossover connects up.

They get gummed up. "Gum" gets stiffer the colder it gets.

There are 3 of them actually 2, I guess:
1st I think is just a throttling butterfly located just downstream of the air-filter.
2nd is under the casted button on the crossover manifold pipe.
3rd is accessed from under the car, its in the bottom of the main manifold section that connects to the head.

There are vacuum lines running to them and electric switches which provide the computer with feedback when they open or close.

It's been a while but I took pictures of the process and I think I posted them on the fourm..

I'll look for them... Good Luck

On the non-turbo engine, the computer will not notice if the egr valve is operating as designed, or bypassed.


Resonance flaps location diagram:

http://www.detali.ru/cat/oem_mb2.asp?TP=1&F=210020&M=606%2E912&GA=722%2E438722%2E600&GM=717%2E446&CT=M&cat=19T&SID=14&SGR=030 &SGN=02

Regarding:
On the non-turbo engine, the computer will not notice if the egr valve is operating as designed, or bypassed.

Actually it will... you have to bypass it and feed it fresh air rather then soot filled exaust.. If I can pat myself on the back... I think I was the 1st guy that proposed the bypassing of the EGR, I was told no way the computer will throw a code, but I tryed it and it worked fine. Search for my post a Breath of fresh air. I was all simles when it worked....

Ha.. I found that old post... Some guys got a little heated when I questioned the old school way of thinking... :confused:

http://www.peachparts.com/shopforum/tech-help/78476-egr-block-plate-97-e300d.html?highlight=Breath+fresh+air

Pat yourself all you like, worked like a charm, and after I saw what was in the intake manifold your simple solution was a work of art!!

Thaqnks for all th ehelp i didnt know about the secound flap will take apart and clean, although that still dosnt answer why the cruise contol stops the surge inless cruise is sensitive enough to smooth engine out.
As for bypassinf the egr it sounds intriguing, has anyone done it?
If so any problems?
there are 2 ways to get codes one from the obdII and the other from the port under the hood. If your saying you recived no codes did you check both? The obdII trips light the one under the hood is for techs.
Anothe r? when you remove intake do you need more than intake gasket? Do you need o rings for tunnels?
Aslo i dindt get an answer on how to check glow plugs or the relay again thanks everyone for help. Greg

This is the thread that tells all about the EGR valve bypass. If you read it all the way through, it will answer most of your questions. If you remove the crossover pipe, you will have to check the rubber "o" rings for condition. Mine were good to go, so I just lightly coated them with some high temperature silicone grease and re-assembled the pipe when I had completed my work. You will probably need an intake gasket, but just make sure you order the correct one. When ordering on line, you will be presented with two intake gaskets for your model depending on your engine number. As for the glow plugs, do a search for "glow plugs", and you will get a variety of ways to check them via the relay, or one at a time if you have the intake manifold off.

http://www.peachparts.com/shopforum/tech-help/78476-egr-block-plate-97-e300d.html?highlight=Breath+fresh+air

Thanks i read the post a couple of times and it has no answers.
Has anyone done it?
Does it send a code to computer?
Has any one read or have the port under hood read for codes after switch?
Does it affect performance?
One of the post says that the egr cools head.
How does it cool head with 1000 degree exhaust gases?
Wouldnt a bypass with fresh cool air cool heads better?
Just looking for answers before i try it.
Thanks all.

Read the entire thread. The first 30 messages cover all your questions, and there are a number of pictures showing the modification.

Actually it doesnt answer any questions it just asked more.
unless im reading the wrong thread. there isnt even 30 messages.
sounds like 97300d did the job but doesnt say if any codes.
as well as your post, did any body have the underhood port(dont know tech term)checked for code?
Ther are no pics of completed job, although its pretty straight foward.
thanks Greg