boxerulez

Ladies and Gentlemen

Today I humbly request any and all tips/advice in curing my cars problems.

I am going to take you through my ordeals in a step by step recollection of the events since purchase.



I picked up this 1994 E220 2 months ago from an estate in my home town, Oudtshoorn, in the Western Cape Province of South Africa.
The car does not have CAT from the factory. It has done just shy of 360 000km now.

I drove it home to East London, Eastern Cape Prov, 900km+/- it was running well and smooth. Little on the low side of the economy spectrum, however it ran good and powerful.

Once I got it home I started digging into the usual suspects and found that the car was running in open loop, set maps, running rich and that is where my economy was going downhill. I started tracing problems and found that the main harness has already been replaced. I proceeded and rewired the coil pack harness, as this was brittle and due to short and cause damage. I also rewired the throttle body harness as this one was already failed, shorting and causing the car to run in open loop.

Once I re assembled all, it fired right up and proceeded to run the cold start loop. As soon as it reached temperature the computer kicked into closed loop and the car ran terrible. Permanently on the verge of stalling, throttle response only there between 1000-2000rpm. Over 2000rpm there was absolutely nothing in it. Would not increase rpm any higher.
running very rich also. LOTS of black smoke.


I went ahead and replaced the MAF with an aftermarket one from a local importer, his parts come highly recommended by a indy a few towns over, so its not the worst quality, but of course it will not be the same quality as a Bosch part.

Car started up in closed loop and took about 2minutes of idling to adjust itself to the new readings from the MAF I assumed, Idle evened out, car ran like a dream, light on fuel again. Drove for a weekend around to the shops, 2 stints on the freeway, just some easy cruising. No Problems.

Monday, I took it to work, all ok. Weather was around 25deg C. After work collected my wife from work. Parked outside her offices and listened to the radio while waiting on her. As she joined me and I started the car, back to the same old poor running as before the replacement MAF.

Limped home and parked it. Next morning it started up perfect again. I suspected OVP as the culprit. Replaced it with a new part made in hungary by Meyle (Who also produce the part for OEM)
After replacement I went to shops with car, little test run. Parked it for 15 minutes at supermarket. Set off home again. On the last hill before my residence, it went horrible again.


Now for a little additional information.

When the car runs fine, and I unplug the MAF, it delivers exactly the same poor performance as when the car just performs poor by itself after a bit of driving.
OVP NEW
MAF NEW
OPENED ECU, no sign of damage inside
FUEL pump relay is good.
Klima is GOOD
Relay units behind fuse box is all GOOD

This leaves ETA Throttle Rewire fail(maybe one of my solders are heat soaking when car is parked)

Or

MAF intermittent fail (maybe a dud from factory, failing when heat soaked)
Because when the car is running poorly and I unplug the MAF there is no change in the performance. It does not improve nor deteriorate.

What can you friendly people suggest to look at?

Regards




Vince

boxerulez

Also if you gentlemen can be as kind as to confirm or deny,

When you unplug the maf on this car, should it go into open loop again and run the default maps, or will it stall?

The supplier of the MAF claims when the MAF is disconnect, the car should run on default maps.

boxerulez

Also another question to consider,

If the ECU is damaged, will I have intermittent problems or constant problems in this regard?

Sorry for the many questions, but you guys in the other time zone will probably only read this when I am getting off work and I do not have internet access at home.

boxerulez

Last night, I thought I would look into the Throttle body wiring again.

Got some better grade CAT6 Silicone network cable with copper cores. Rewired the entire thing.

Once again, still the same poor performance. It seems it is going into "stumble" mode as soon as it reaches operating temperature now.

I was monitoring the radiator hoses while monitoring the engine performance. It was running at +/- 950rpm when cold, radiator hoses started warming up, as soon as the thermostat opened and there was flow in the radiator the idle started stumbling again, on the verge of stalling.

Apply small amounts of throttle, at a constant, revolutions are hunting.

I tested each plug wire with a extra plug and spark is coming through still.
Injectors are pulsing, I can hear them, and the car is running so rich I can basically rule out Fuel problems.

What I do not understand then is Spark and Fuel is there... air is added via mechanical cable. Why does it stumble?

Also, after last night, I tried starting it this morning before work, it is now still stumbling, even when cold.

I am starting to lose hope for this.

Someone is going to try and read fault codes and examine live data while the car is running in this manner.

Any feedback as to what to look out for on the data?

ChrisVannoy