260E loss of power while running

[cc260E]

I have fantastic 260E , 1988, 360 000 km, running fine, except some times , where for a few seconds, there is a loss of power which can go up to total engine switch off.

Fuel relay, ingnition module, injection module, fuel filter, fuel pressure accumulator have been changed.

Did anybody experience this inconvenience?

Any suggestion on what I can do to overcome this

[csnow]

Could be the fuel pump (or pumps). Symptoms match.
Would be a shame to have replaced all of that stuff if the pump is the culprit...

Also could be electrical.
Check cap and rotor for a start.

[sbourg]

Does the loss of power and stalling occur at idle, or while moving?

Steve

[cc260E]

thanks to both of you that replied so quickly.

I never made any specific test on the pumps themselves, just have set a LED to check while running, if 12V was missing from the pump relay and no such lack was detected by the LED.

The stalling occurs also at idle.

I should have added that the High voltage distributor, high voltage transformer, and HT cables from transformer to spark plugs have also been changed.

Regards

[zorin]

I have similar problem with my 260E. When I bleed fuel lines , on top of the fuel distributor , it helps , but for a while.

Make sure you have no vacuum leak at the injectors seal(spray Carb cleaner while the engine is idle to see if engine noise changes, if so then you have a leak at that injector). Also there is a small mesh at the end of the fuel line going to the distibutor. It could be dirty.

[cc260E]

Thank you zorin for your suggestions,

I changed also the mesh on the fuel line at diffusor entrance, together with all injectors plastic fittings and seals.

I am suspecting some erratic malfunctionning of pressure regulators that are in the fuel distributor.

any idea on how to check that?

cheers

[zorin]

I think the EHA controls that. Have you measured the current at EHA? It should fluctuate around zero + or - some mA. Also meaure the duty cycle or voltage at diagnostic port , pin 3, once with ignition on , engine off and once while engine is idling at operating temperature.

[cc260E]

thanks zorin
coudl you tell me what should be the voltage reading on pin 3?

I ma now suspecting the fuel not to be at teh right pressure in the fuel distributor.

Any idea how to masure the fuel pressure in the fuel distributor?

Does any body have a foto or a schematic of the bottom part of this distributor.

thanks

[zorin]

While the engine is running and it is at operating temp, the voltage should be fluctuating at about 7 V on pin 3.
Do a search for "Duty Cycle" on the site. Also see Steve's article in DIY section.

It happened to my car few years ago, while cruising on the highway. The car was towed home. Next day , the engine started fine but stalled after run few miles. It can be re-stared the engine with lime-home mode to continued the trip. I changed few parts related to electicity one after the other. Finally, find the broken oxgensensor cable. Since then car runs fine. Just the idea, it is easy to check the cable attached to O2 sensor.

[csnow]

Have you ruled out the pump(s) at this point?
Sorry to be 'persistent' (a nag) on this, but intermittent is their 'signature' failure mode.

[cc260E]

Thanks Renny

My car is fitted with european standard, and do not have the catalysator ( not mandatory in 1988). So do not know whta is this O2 sensor, where is it located and yo what it is connected; Could you help and give me theses info.

Thanks csnow,

I have not yet sorted out the pumps ( they are 2), the defect occurs for few seconds only swhen driving, so it is very difficult to check the pumps on a working place.

I suspect also the regulators one inside the distributor ( I have been told) and one outside.

Do you know what to do to measure the fuel pressure while running?
Doing so I expect to be able to see something.