W124 idle surging, sluggish at low RPMs
04-30-2012, 08:44 PM
#1
Newbie
Thread Starter
W124 idle surging, sluggish at low RPMs
car:
1995 E320 (its a California car if that make a difference)
188,000mi on the odometer
Symptoms:
-rough idle
-surging 500-1500rpm (intermittent, but its happening a lot more frequently)
-stalling (mostly an issue when there is added load from the AC)
-drastically reduced performance when accelerating (only while surging is present)
also worth noting,
the CEL is does not come on at all. There doesnt seem to be any error codes stored. Using the diag button/LED does not show any flashes and neither does my home built code reader.
Newer parts (issue appeared 10kmi+ after these services)
-"KAE" OVP relay (single fuse not blown, roughly 1-2years/30k mi old)
-all new copper fuses (replaced late 2011)
-three new coils "STM" brand ? (I was trying to get bosch, but they didnt have 3 in stock, and the owner of the VW/mercedes shop said he uses this brand)
-Bosch (maybe NGK, I don't remember) spark plugs replaced with coils.
1995 E320 (its a California car if that make a difference)
188,000mi on the odometer
Symptoms:
-rough idle
-surging 500-1500rpm (intermittent, but its happening a lot more frequently)
-stalling (mostly an issue when there is added load from the AC)
-drastically reduced performance when accelerating (only while surging is present)
also worth noting,
the CEL is does not come on at all. There doesnt seem to be any error codes stored. Using the diag button/LED does not show any flashes and neither does my home built code reader.
Newer parts (issue appeared 10kmi+ after these services)
-"KAE" OVP relay (single fuse not blown, roughly 1-2years/30k mi old)
-all new copper fuses (replaced late 2011)
-three new coils "STM" brand ? (I was trying to get bosch, but they didnt have 3 in stock, and the owner of the VW/mercedes shop said he uses this brand)
-Bosch (maybe NGK, I don't remember) spark plugs replaced with coils.
05-09-2012, 06:22 PM
#5
Newbie
Thread Starter
EDIT:
Went to go tow the car home, and I brought a can of gas, even though the gauge read nearly 3/4 tank and the car started. Took it to the gas station, and it took an additional 14.8gal of petrol, equaling 17gallons total. The no start issue that i was having earlier seems to be directly linked to the false gauge reading, and NO gas.
This might be unrelated to my rough idle/surging/hesitation issue,
A few days ago, I noticed a slight buzzing sound that seems to be coming from inside or under the intake manifold. The noise gets a little louder when I open the throttle body (with the intake pipe removed). The noise is consistent with the key in the 'On' position, and sustains for several minutes with the key-On, and stops with the key in the Off position.
Earlier Today:
The car started running a little rougher (more frequently) and then died while driving. Now the motor turns over, but it will not start.
I removed the 15mm cap that covers the flared fitting located on the rail, and pressed the nipple. The only thing that came out was a fumes/pressure. Does this mean that the fuel is not making it to the rail?
Went to go tow the car home, and I brought a can of gas, even though the gauge read nearly 3/4 tank and the car started. Took it to the gas station, and it took an additional 14.8gal of petrol, equaling 17gallons total. The no start issue that i was having earlier seems to be directly linked to the false gauge reading, and NO gas.
This might be unrelated to my rough idle/surging/hesitation issue,
A few days ago, I noticed a slight buzzing sound that seems to be coming from inside or under the intake manifold. The noise gets a little louder when I open the throttle body (with the intake pipe removed). The noise is consistent with the key in the 'On' position, and sustains for several minutes with the key-On, and stops with the key in the Off position.
Earlier Today:
The car started running a little rougher (more frequently) and then died while driving. Now the motor turns over, but it will not start.
I removed the 15mm cap that covers the flared fitting located on the rail, and pressed the nipple. The only thing that came out was a fumes/pressure. Does this mean that the fuel is not making it to the rail?
Last edited by damnDSM; 05-09-2012 at 07:23 PM.
05-24-2012, 01:28 AM
#6
Newbie
Join Date: Nov 2005
Posts: 1
Likes: 0
Received 0 Likes
on
0 Posts
For everyone who's having starting or idle issues with 93 -95 W124 3.2 or 2.8 liter. Here's how you get your car to idle or start correctly. These problems are mostly related to old parts on old cars.
You only have fuel and spark in this equation. You have to write down all the parts for fuel and all the parts for spark.
If you have not replace the upper wiring harness in your car, or don't know the condition of it, stop right there. Do this first. Just moving one these old wires can cause your car not to start.
If your harness is good, pull the codes from your computer and clear them. Drive around and see which codes come back. This is a good starting point of what to replace first.
Next make sure all the components on the fuel side are good. Fuel pump, relay, regulator etc. If this all checks out you can move on to the spark side.
On the spark side you some of the main parts are MAF sensor, Temp sensor, Crank position sensor, coils, trottle body, fuel injectors, spark plugs, control unit, etc.
Start replacing the cheapest parts first until your problem goes away. If you have a good mechanic who works on European cars , he has the tools to test most parts, and will save you time and money in the long run.
You only have fuel and spark in this equation. You have to write down all the parts for fuel and all the parts for spark.
If you have not replace the upper wiring harness in your car, or don't know the condition of it, stop right there. Do this first. Just moving one these old wires can cause your car not to start.
If your harness is good, pull the codes from your computer and clear them. Drive around and see which codes come back. This is a good starting point of what to replace first.
Next make sure all the components on the fuel side are good. Fuel pump, relay, regulator etc. If this all checks out you can move on to the spark side.
On the spark side you some of the main parts are MAF sensor, Temp sensor, Crank position sensor, coils, trottle body, fuel injectors, spark plugs, control unit, etc.
Start replacing the cheapest parts first until your problem goes away. If you have a good mechanic who works on European cars , he has the tools to test most parts, and will save you time and money in the long run.
