190 starting problem

[JohnG]

Hello all,

the car is an automatic 1.8 litre 190E (1991), 205,000 miles. On turning the starter key, the engine turns over reasonably well but is very sluggish to start although, with persistence, it will start. When it starts, it ticks over roughly and stops after about a minute. It seems to run as normal if my foot is on the accelerator but it lacks power when I attempt to drive it. This problem appeared suddenly and unexpectedly after the car had been left outside without being driven for several days.

Other things that might or might not be related. 1) the radiator is leaking. I suspect that this could be damage caused by the very rough swaying of the engine after the fault described above developed. There was no evidence of a leak beforehand. However, there is water in the cooling system - the leak is very recent. 2) About a week ago, the fuel gauge needle occasionally started to fall towards empty in an erratic and unpredictable manner before rising again to its correct postion. This behaviour lasted for a day or two and then appeared to sort itself out.

Any suggestions would be very welcome.

Regards

 

[JohnG]

The problem has been solved. I phoned a local garage that specialises in repairing Mercedes cars. Apparently, the difficulty with starting that I experienced is common, especially at this time of year. I was told that it is caused by condensation around the high tension lead under the distributor cover. Merely leaving the car in my garage overnight appears to have solved the problem.

The radiator problem is unrelated.

 

[television]

Thanks for posting back with the answer

 

[wireman]

Your fuel gauge problem may be anywhere in the fuel guage circuit, a poor earth at the tank end or the sender itself are possible maybe the connector to the sender is dirty, if the oil pressure and temp gauges were also affected it may be a poor 12v supply from the fuse block which is prone to defects due to water ingress if the lid has been left incorrectly closed for any length of time. Do make sure the fuse box lid is fitted correctly and firmly closed.

The innards of the fuel sender consist of a switch for the you're about to run out lamp and a rheostat for the gauge with a wiper that's coupled to the float, wear of the wiper or resistance track can cause your problem.

Your engine wobble during the missfire could indicate the front engine mounts are getting tired and need replacing. Poor mounts could damage the drivetrain rubber universal joints due to missalignment of the sagging engine/transmission.

I would recomend throughly cleaning all the ignition HT components since any surface dirt that builds up on these parts will hold moisture and cause the problem to resurface.
Replacement is often the best bet with HT parts.

 

[JohnG]

wireman,

thank you for your comments. The fuel gauge problem does sound like a poor electrical connection somewhere. It is intermittent and only the fuel gauge is affected. Other gauges work as normal. Also, in the last week or so, the problem has not been evident, but I expect it to reappear.

Regarding the condensation on HT leads; the garage I contacted suggested thorough cleaning of everything under the distributor cover followed with a spray of WD40. The latter is something of a family joke as my wife regards WD40 as a cure-all for everything!

I will check the engine mountings. When the engine was running roughly it would cut out
unexpectedly and it often did this with quite a loud metallic clanging sound. It was the sort of rough running that could easily do damage.

Regards,

John

 

[wireman]

Don't bother putting wd40 on your ht components unless they have been drenched in flooding and you need to get it going quickly, the stuff just sets into goo and will give you more trouble in the long term.

WaterDisplacer40 is temporary at best and not very good at most of the suggested uses except water displacement, the only thing I use it for is tar spot removal.

The clanging during unsettled/rough running sounds like you might have metal to metal contact inside the mounts when they are stressed to their limit of displacement, if this is so replacing them will make you think the car is new. Changing them is easy if you can undo the bolts, one on top and one below (10mm hex key?) accessed upwards through a hole in the chassisleg/bodywork. Avoid the cheapo mounts from GSF.