Sustained low rpm driving causing a bad hesitation...then clears up and is fine?

[scott66]

I wouldn't doubt its a fuel delivery problem for the hesitation...being the transfer pump def helped. I'm thinking the inline pump...I kinda want to replace it anyhow, being...I'm making a 1200 mile trip on a 1987 fuel pump on a car with in excess of 200k miles...haha..

I had similar problems with my 85 VW Golf and the culprit was the inline pump...except my issue was that the car just died and would not start again untul it cooled off...

Anyways, I drive my 195,000 mile 1990 325iS all the way from Washinton (the State) to Virginia (thats over 2800 miles) in just about 3 days with no issue, good luck with your drive.

[ELVA164]

I don't know if this would be what you're talking about, but in the manual for my car it says that if you were driving at low RPM for an extended period or stuck in traffic, it may cause carbon deposits to build up on the plugs. That could cause hesitation and loss of power. It recommends driving at 3000+rpm for x miles to clear them off. Just a thought.

[dnguyen1963]

Its a Duralast but says BOSCH and Made in Italy right on it. All Duralast ignition stuff is made by Bosch anyway.


Anyone know of any cheaper routes than the stock Bosch unit that are just as good? I just have a hard time spending around $200 for a nothing special inline pump just because it says Bosch on it. All auto parts stores have a similar price.

Tre pump can be had for $65. I have had that unit in my car (single pump '88 325ic) for awhile now...works great so far. You would have to search to see if they offer an in-line pump. I believe that they do. Stay away from AirTex pump...piece of shit.

[Chriskbmx]

you can use the tre as an out of tank pump 2 i have heard. but who knows. i just ordered mine for my 318is.

[strang3majik]

^^^Whats the tre?

But the in tank pump is only 4-6psi if thats what your saying.

And dnguyen...where and what brand is the $65 one?

[dnguyen1963]

^^^Whats the tre?

But the in tank pump is only 4-6psi if thats what your saying.

And dnguyen...where and what brand is the $65 one?

http://www.treperformance.com/FuelPumps/TRE255FuelPumps.html

[nny403]

Update on mine; the pressure regulator greatly helped the issues I was having but it's still going to be narrowed down to the AFM. When it's cold and running a rich mixture it works fine, as the engine warms up the symptoms become apparant again.

The 1800-2200RPM lag seems to indicate the AFM is sending the wrong signal to the ECU. Unless I'm mistaken this is going to have to be the next step.