300TE-24 bad running/misfire chaos!

[Owen49]

Hi

My '92 300TE-24 struggles a bit after cold starting but then runs OK for a few minutes. After a little while moving off from a standstill becomes nearly impossible unless I shove my foot flat to the floor and then (obviously) back off again pretty quick (unless I want to end up in the back of the car in front!).

At first I thought it was a sparking issue, so replaced the plugs and the leads, to no avail. The previous owner reckoned he'd fitted a new distributor so I've left that alone. Someone has suggested it might be a metering issue caused, perhaps, by a small whole somewhere in the air-metering system. I've thought it might be timing, but can I adjust this? What adjustments can be made to the Siemens condenser unit sitting on the right of the engine?

Overall the effect it has is that of not getting enough fuel - it'll pop and backfire quite a bit but once off the mark it's fine - but I've run a whole load of injector cleaner through it and it just seems to be getting worse!!

Please; any ideas?

 

[Myros]

I don't think you can adjust the timing

except by very small amounts by means of the resistor plug ( assuming the 24v has one, the 12v does). Certainly not enough to produce or negate the symtoms you are describing.
When you say the previous owner did a new dist cap, did he do a new rotor arm. Deterioration of that can cause similar problems. It's worth having the dist cap off to have a look. The cap itself may be full of crud or have failed in som other way, so don't leave it out just on someone else's say so.

I'll back off here because I only have the 12v to base my thoughts on. Perhaps some of the 24 valve owners will pitch in soon.

 

[Owen49]

Thanks for the quick response!

Previous owner also changed the rotor arm as one of the things he pointed out was that there are 2 different distrib' caps available and the rotor arms are not interchangeable unless you want to fry the condenser.

Another headache lies in the fact that I managed to shear the head off one of the bolts that hold the cap on. It's firmly in place but I'm slightly scuppered there when it comes to taking it off again.

I suppose my main worry is going through and replacing each component in line as it's bound to be the last one I get to!

 

[Myros]

I found that bottom allen bolt

on the dizzy to be one of the fiddliest things I have ever done. It took me ages.
It sounds more likely to be the fuel injection and enrichment side of things. What's it like once you get it up to operating temperature.

 

[Owen49]

It gets worse once it's up to temperature. The first mile or so is fine, then it deteriorates. Once moving it's all OK - it's town driving that it really suffers. As an aside I experimentally disconnected the EGR system but that makes no difference of course. Though a knackered coil has been suggested I am now definately erring towards it being a fuelling problem. Air-flow meter perhaps?

 

[Myros]

it could be any one of a number of things

or a combination of them. I don't want to start speculating idly as it scares me more than you.
Have you had a good search on the key words?

 

[Owen49]

Doing that now! Plenty to go on over the weekend, by the looks of it!

 

[ianjak]

overload relay??