Parts Catalog Accessories Catalog Tech Info Tech Forums
  Search our site:    
 Cart  | Project List | Order Status | Help    

Go Back   PeachParts Mercedes ShopForum > Technical Information and Support > Tech Help

LinkBack Thread Tools Display Modes
Old 07-17-2001, 03:14 AM
Dan Dan is offline
Registered User
Join Date: Jun 2001
Posts: 29
Hi, I have an '89 300CE wth 70K miles that continues to challenge the dealer and I with a hot start problem -- excessive cranking and rough running for several minutes . Cold starts and hot starts within about 5 min of shut-off are both OK. No other drivability problems, other than occasionally when idling at operating temp, hot start rough -run symptom reappears on acceleration.

The original suspicion was fuel pressure leakdown, but it doesn't seem to be that.

Any suggestions appreciated. Here's the facts:

- maintains fuel system pressure at 2.9 bar for 60 min, according to dealer

- recent new parts: OVP relay, fuel pump relay, fuel pressure accumulator, EHA, fuel pump check valves, distributor cap, rotor, and spark plugs. (The EHA, distrib cap, rotor and plugs were replaced for other reasons; the others, my failed attempts at solving suspected fuel delivery problem.)

- air flow sensor plate zero position OK in fuel distributor

- coolant temp sensor for EFI measures OK at 20C but has about twice the resistance (~ 434 ohm) at 85-90C compared to spec. Is this enough to be the culprit?

thanks in advance...DAN

Reply With Quote
Old 07-17-2001, 06:12 AM
Registered User
Join Date: Jan 2000
Location: New Bedford, MA USA
Posts: 1,583
I didn't notice seeing that you replaced the wires. This can be an issue.
Jeff Lawrence
1989 300e
2000 Dodge Grand Caravan SE
No matter what you fix, there will always be something else to fix..
"Warranty" is just another way of postponing the inevitable.
Reply With Quote
Old 07-17-2001, 08:57 AM
G-Benz's Avatar
Razorback Soccer Dad
Join Date: Apr 2001
Location: Dallas/Fort-Worth
Posts: 5,711
OVP was the cause of my hot start problem, but coolant temp sensor caused an erratic idle problem I once had.

Also, a faulty wiring harness shorting at the EGR was a culprit for poor driving performance. This was replaced free, as a service bulletin indicated that there was a harness problem with some W124 models.

I also had the plug wires replaced, and found that the spark plugs were gapped too wide, so car missed during load conditions. Put in new plugs that were correctly gapped.

Also replaced fuel filter (which you didn't mention in your replacement parts list).

Check the fuse at the top of the OVP as will still cause big problems if blown...
2009 ML350 (84K) - Family vehicle
2001 CLK430 Cabriolet (71K) - Wife's car
2005 BMW 645CI (124K) - My daily driver
2012 Mustang V6 (60K) - Daughter's car
Reply With Quote
Old 08-06-2001, 10:34 AM
Dan Dan is offline
Registered User
Join Date: Jun 2001
Posts: 29

Thanks for all the suggestions and posts.

The culprit to this hot start problem anyway was the fuel injection nozzles. When they were all replaced. all the drivability issues vanished.

This 124 is an '89 300 CE with only 70K miles, previously driven for most of its life by an older lady, who probably didn't know what full throttle was. Use it or loose it, is what the technician related to me.

Kudos goes to Brooklyn Motoren Werke in Brooklyn, Wisc for their efforts!
Reply With Quote


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

Similar Threads
Thread Thread Starter Forum Replies Last Post
FS: MANY W124 Parts & more! Detailed PICTURES! GREAT Items! GREAT Deals! CHECK IT OUT FA22 Mercedes Used Parts For Sale & Wanted 22 09-09-2004 07:22 PM
What sensors to replace in w124? netken Tech Help 12 10-31-2003 01:33 AM
Anyone solve the problem of hot air fromside vents ona W124 acha3 Tech Help 9 08-18-2003 02:11 AM
300D W124 loosing power when engine hot hummer253 Diesel Discussion 2 08-14-2003 07:48 PM
W124 front camber prob after lowering sjsfiji Performance Paddock 8 07-04-2003 06:57 PM

All times are GMT -4. The time now is 06:41 AM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2016, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2011 Pelican Parts - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page