When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
So, I've covered my 190 2.3 extensively on Benzworld and it has been a big ongoing project.
@195,000 miles car has never really run perfectly, the engine itself is good (great compression and burns no oil). Idles perfectly when warm.
Issues:
Difficult cold start, if you give it gas when cold the engine will die. Has to run for 5-10 seconds.
Very slow, slower than my 300D. Feels like I am dragging a boat anchor. I have to floor it. Especially bad with A/C on, it is a chore to hit 40 mph.
Relevant things I have done:
head-gasket and timing chain- head was decked, I did NOT install an offset woodruff key
190E 2.6L 1989, 190E 2.6L 1988, BMW 535dXdrive 2014, BMW 428i 2015
Hi Nate. So your cold start and running issue is because the system is not enriching the air/fuel mixture while cold.
The 3 components that govern this is:
AFM pot
Coolant temp sensor
ECU
To make sure my long distance diagnostic hunch is correct, you will have to measure your EHA current. I have a post of the expected behavior on the other side of the "World".
Read that if you like on the expected EHA current when cold. It is titled something like "EHA current, how is it supposed to behave anyway" or something to that effect.
If you have the means to measure EHA current that is the best starting point.
You should also measure your Coolant temp sensor resistance and compare against the spec. Perhaps measure it at room temp and post it here.
It is a remote possibility but we have seen one example in the not so distant past of the ECU being defective and not providing the open loop enrichment.
BTW, after the FD rebuild, you should post your duty cycle reading here one more time (at operating temp). Remember to take measurements at idle and immediately followed but that at 2500rpm.
The possibility of the accumulator causing running issues is zero. It really can not effect your fuel pressure while the pumps are running. It is only there to maintain pressure after the pumps turn off.
is this plug with the cracked wiring the coolant temp sensor you are referring to? This would explain why my symptoms seem erratic? Some days it's fine, others it's not.
the car is operating in closed loop. New oxygen sensor and multimeter confirms closed
Last edited by natejgreene9871; Sep 13, 2021 at 09:39 PM.
190E 2.6L 1989, 190E 2.6L 1988, BMW 535dXdrive 2014, BMW 428i 2015
That indeed is the coolant temp sensor. One pair goes to the ECU, the other pair goes to your instrument cluster.
The cracked insulator could be a problem but not necessarily.
Does you temp gauge in the instrument panel behave erratically ever? Perhaps that pair is OK?
If the temp sensor is out of range that should throw a code (I believe), do you have a OBD-1 code reader?
the sensor did go through the parts washer when the head was machined so it is suspect. I bought a new one ($20) and will try to take the plug apart and repair 1265403081. Plug is $90 at dealer!!
190E 2.6L 1989, 190E 2.6L 1988, BMW 535dXdrive 2014, BMW 428i 2015
The plug is one part you can buy at the junk yard. $5 at pick and pull and it is not a wear item. Never seen one as bad as yours. Mine is original.
Good luck and patience with the repair Nate.
This may not be your problem but it sure needs to repair.
190E 2.6L 1989, 190E 2.6L 1988, BMW 535dXdrive 2014, BMW 428i 2015
Originally Posted by natejgreene9871
Also, FYI this sensor has no effect on the instrument cluster temp gauge. Still reads temp with it unplugged.
That is surprising. I have never checked this but the circuit schematics only show 2 temp sensors plus the aux fan sensor. 1 of the temp sensors goes directly to the ECU and the other directly to the Instrument cluster. I always believed the connector you replaced had 2 sensors in it for this purpose.
I'm not aware of yet another sensor on the cylinder head for the temp gauge.
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Slideshow: A one-of-one U.S.-spec Mercedes-Benz SLR McLaren Roadster became even rarer after a factory-backed transformation at McLaren's headquarters.
