I have a '89 260E with 130K miles on it. Lately, it has been having rough start and idle problems. I have since changed the O2 sensor, the EHA, plugs, both fuel pumps, fuel filter, injectors, and the air filter. It has since been running much better, but still has a rough "baubling" /engine bucking effect for about 6-10 seconds after starting.

The weird thing is that the the roughness gets worse as the car is started throughout the day, rather than initial start-up in the morning. Seems also to get worse during warmer weather.

Once started, everything works fine. Just would love to work out these minor bugs. Any suggestions on what to replace next?

Thanks!



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Eric

Fuel pump relay by chance?

Since it is temperature dependant, it could be the temperature sensor...

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J.H.
'86 300E

I didn't see the OVP relay on the list, but I assume you have changed that too. Otherwise, old versions can perform poorly with age, even if the fuse on top is still solid.

Also, the symptoms sound like there is still fuel pressure loss. How did the EHA replacement go? I have heard of air leaking in through a bad EHA gasket.

Cheers, Andrew Seidel.

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89 190E 2.6
83 300TD Turbo
75 240D

Thanks for the advice. I have not replaced the OVP relay yet. Perhaps that's the best way to start. Does it sound like pre-ignition problems or fuel? I certainly don't mind bying the parts but would love to narrow it down a bit.



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Eric

I e-mailed more details. I still suspect fuel pressure. Hopefully Benzmac and crew will catch this thread, as the always know best.

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89 190E 2.6
83 300TD Turbo
75 240D