CALIFORNIAICE

First off, I have a 1992 300e 2.6L.

It all started with a gas/ fuel smell in the cabin area of the car. The car started intermittently surging on idle (never flies above regular idle, just drops from time to time to the point before stalling) The smell ended up being 2 leaks, 1 from the gasket around the Fuel pressure actuator (FPR $275, REPLACED), and one around the Fuel filter ($180, Fuel filter replaced, and leak fixed also). After those leaks were fixed the surging continued, but it got worst. Now it actually stalls! First stall was from backing out (from Reverse to Drive), second one is from driving up hill, Up to recently I couldnt even drive down the street without stalling at least 5 times.

Replaced the O2 sensor yesterday with a OEM Bosch one ($230), hoping that would of been the problem (Check Engine light, Excessive smoke/ water from tailpipe Fixed) STILL STALLING.

Does anyone have experience with this? Only asking because Ive spent a whole lot of money already, and cant afford replacing another part, that it probably isnt. Not to mention its my only car, and I cant afford to leave it at a shop overnight/ days. I ruled out the OVP relay, because no other sensors are set off, and also a vaccum leak because the idle doesnt spike up. (is this a wrong assumption?) Im thinking Fuel pump, Fuel pump relay, ignition coil, crank position sensor, or maybe some other. Search Feature was used many a times, but couldnt find any symptoms that described mine.

Where to start first? Any clues I need to lookout for?

THANKS FOR READING MY ESSAY!!!! I NEED HELP SO BAD!!!!! ONLY CAR!!
and I commute with my 4 yr old daughter.. =(

So again the car surges on idle (never spikes), runs fine on the freeway, and Stalls.

funkgab

what color is your powersteering fluid? and what color is the smoke? hopefully its not a headgasket and your engines flooding or something..

but it can be the OVP, mine didn't have a weird idle or anything, even though i had a couple vacuum leaks and it would stall on startup if i put the accelerator down its a pretty cheap part used

Dysphoria

Weird question but what does the colour of his power steering fluid have to do with anything?

CALIFORNIAICE

Ill checkout the color of the power steering fluid in awhile. What color should it be? THANKS FOR REPLYING! I didnt think I was going to be finding any sort of help.

UPDATE: replaced MAS fuel pump relay, OVP relay, cleaned intake parts yesterday. No difference. Although i did realize it happens when its in gear, espescially when its in reverse.

chlippo

I think your fuel pressure is dropping. There is a little adjustment screw next to the fuel distributor. I have a picture showing it my home pc. But if you want have a look on youtube there is some video showing how to.

meanwhile you can apply a little gas (by pressing a bit the gas pedal) before putting in reverse or any other gear (not a lot of gas, just around to get the rpm needle to 900 to 1000 rpm)

CALIFORNIAICE

Pics pls!!!

chlippo

Does your car still smell gas?

here is the throttle adjustment im talking about. I think its a hex screw. it is sensitive so turn a very very little bit clockwise and then wait 1-2 mins see how the car reacts.

I dont remember if it was clockwise or counter-clockwise to adjust for more or less. You will have to try. worth a try! You will need the correct screwdriver (hexdriver or what ever it is called)

chlippo

here is the screwdriver u need

http://www.ebay.com/itm/Snap-On-Mode...item2a18f115f4

rayhennig

That is not a throttle adjustment. It adjusts the richness of the mixture using a mark/space ratio or 'Duty Cycle' to control the injection time - in simple terms.

Buy a cheap multimeter and measure it across pins 2 & 3 - lots of advice about this here and elsewhere.

Make sure you have no vacuum leaks and that your ignition system is in perfect condition with quality plugs, leads and distributor cap/rotor before you worry about duty cycle.

Good luck.

RayH

CALIFORNIAICE

Thanks so much for the feedback Chlippo..
Also no, it doesnt smell like fuel anymore...

CALIFORNIAICE

Thanks also Rayhennig, i'm nowhere being mechanically inclined so when you say pins 2 & 3 what do you mean exactly, and where do i find it? Thanks!! Plugs, and wires have been replaced by PO before the sale. The car ran fine for several months, until the fuel leak started happening. Turned out to be my Fuel Pump Regulator, I got it replaced with an OEM Bosch part. The fuel smell went away, but eversince that leak.. the idle surge never went away. Since then many parts have been replaced, and it really only does funny stuff when its in gear, before about 5-10 mph.

Need more help guys please keep it coming, CPS sensor replaced ($200+), and its still doing it. could it be my accumulator?

funkgab

did you get a brand new ovp? still sounds like it on the idle surge part

how is your EHA?

chlippo

try what i suggested you first...easy and wont cost you much more than the screwdriver.

CALIFORNIAICE

Hey Funkgab,

No, I gotta used one, a couple of used ones actually. aside from the idle surge will it have any other symptoms? When I spoke about the Fuel pressure actuator, I actually meant the fuel injection regulator aka EHA. haha. I'm stopping by a parts dealer tomorrow, ill try to see how much he'll charge me for one.

THANKS!! any kind of INFO, or ADVICE has been very helpful!! ill keep you updated.

CALIFORNIAICE

UPDATE:

After replacing all the parts, I finally realized im spending way more money on parts that I didnt necessarily need to replace just yet, and took it to a good mercedes mechanic.
He ran a bunch of tests, and attempted to diagnose the car for a few hrs, after finally going against the parts I told him that has already been replaced, he figures out that plug 2 & 5 are corroded due to bad wires.

I know this will definitely cause a misfire, but wont it misfire while it going on the freeway also? it seems like when i'm going past 15mph the car runs great..

any feedback? ill keep you guys updated after replacing all my plugs, and wires.
ANY SUGGESTIONS? im thinking I might as well get BOSCH everything, or is this necessary? will any local parts store parts be just as good? also i'll be picking up a new ovp, just in case.

THANKS AGAIN GUYS!!

P.S.
During all this madness, ive been driving the car. I'm so afraid i'll make things worst. Unfortunately I just dont have many options.

And Chlippo, if after these previously stated parts dont do it, ill definitely be doing what you've suggested. I'm just afraid to mess with it right now, any links to the video?

London380sl

I doubt this will solve your all of your problems but I'll throw it out. Use top tier gas. Check this website for an explanation of top tier gas and for retailers - basically it's the major gas chains (www.toptiergas.com). I had a problem with surging idle and low idling speed and went through the same sort of thing you doing now throwing parts at the problem. I had read that using top tier gas could solve this problem. I was skeptical but after a couple of tanks of gas (Shell in my case) the surging issue seems to have gone away and my idle speed has gone from 500 rpm to about 600 rpm. Worth a shot.

CALIFORNIAICE

Thanks for your reply london, i know what you mean by this.. i only use shell, chevron, or 76. 91 at that. After this whole issue though ive been talking w124 with my dad, seeing as he has a 91 300te with 245k miles. (Runs smooth, and fast). He told me he only uses 89, since then ive been gassing up with 89 only. Thanks again..

CALIFORNIAICE

Guess what?!?!? Bought oem wires, and bosch copper plugs.. SO FAR, SO GOOD! Fingers crossed. Ill chdck back in in about a week.

funkgab

man it turned out to be that simple? so all you needed was a tuneup..

i had a couple OVPs as well but nothing worked like a new one, and its not that expensive..

but thats great news man.. check the plugs/caps regularly and see if you can return anything you don't need so you get some money back

CALIFORNIAICE

Funkgab,

Damn! spoke too soon. After 2 days of bliss, the idle surge continues.. stall/ power loss is gone though. just a random idle surge when im stopped at the light. Next guess is my IAC.

HERE WE GO AGAIN!! ill keep you guys posted brother

CALIFORNIAICE

Any help with the iac location? Pics pls...

CALIFORNIAICE

So an Epiphany happened!!

Right when the whole fuel leak issue was happening, one of my pulleys was making a whining noise, that got louder as I accelerated. That eventually went away after awhile, and I just figured it fixed itself. Yesterday I left the car running as I ran into the house to grab something real quick, Before I even got to leave the car there was this loud noise coming from under the hood. The first minute it was on, I actually thought it was a plane flying over. Looked under the hood, and realized it was the same pulley. Turns out its my Smog pump. Can anyone verify that this can cause the idle surge? Today I started the car, and the jet engine sound is gone, but how long can I keep driving the car before I need to replace this part before I need to worry about a fan belt meltdown?

Thanks again,
Mitch

funkgab

sounds to me like your having vacuum leaks.. what do you mean by jet engine sound? do you hear air?
make sure all your connections are tight to the eha and everything, a vacuum surge makes the rpms flutter which causes the stall

CALIFORNIAICE

The original whining sounds like theres something rubbing on the fan belt. No not an air seeping like sound. Do you know that wooshing sound planes make when flying over your house? It sounds like that, but coming directly from my smog pump. Do u think a bad smog pump can cause an idle surge? Ill chdck the lines by the eha tomorrow during my lunch break. Thanks for that idea!

CALIFORNIAICE

P.s.
Since replacing the plugs and wires.. nomore stalling issues, and power loss. Just random surge while at a light.