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90 model 740GL auto, B230F w/220,000+ miles

Guys, I've got a problem with the motor bogging down upon acceleration. If you back off the pedal just a little it takes off sometimes and will run up to speed and run normal until slowing for traffic. When pulling a hill it lugs until it shifts in lower gear and then it usually takes off and will get up to speed. If your climbing a real hill (very steep) it just slows to a stop chugging all the while. I pulled the distributor and cleaned up the cap as it had some oil in it and slightly filed the contacts, reassembled and it did seem to help as I was able to drive 150 miles home but it's not fixed by any means. I would appreciate any and all help with diagnosing this problem. Bruce

Reply to
Bruce
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There are a few possibilities that spring to mind: When was the timing belt last replaced? This sounds like what happens if it hops a tooth, poor low rpm response and picks up dramatically around 3500rpm. Spark plugs in need of replacement will also sometimes behave this way. Another possibility is that your loss of power is the knock sensor backing off the timing. That could be caused by an overly lean mixture (low fuel pressure from a clogged fuel filter or failing fuel pump). Oddly enough you might also be running too rich of a mixture and at partial throttle the oxygen sensor is leaning it out, and at full throttle enrichment the engine is going far too rich. Just as a general rule when diagnosing any problem, check all the vacuum lines for cracks, being loose, or popping off

Reply to
Bill Bradley

I had a bad fuel pressure regulator cause similar symptoms, found a junkyard part for a few bucks and popped it in, been fine ever since.

Reply to
James Sweet

Reply to
Bruce

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Bruce

Reply to
Bruce

This has the Bosch fuel system with an air mass meter right? Sometimes the AMM fails intermittent at first, also could be oxidized contacts on the connector.

Reply to
James Sweet

No it's the Regina System James

Reply to
Bruce

I did try an new (used) fuel pressure regulator this morning from a local salvage because this thing is still crapping out on me everyone and a while. It didn't help. I left it at the shop for a diagnostic to find the problem. They said this afternoon that they wouldn't be able to look at it till Monday. Anyway, that's my update on the continuing saga. Bruce

Reply to
Bruce

Well the word is "Fuel Pump" is weak Ordered one this evening and will get it installed a.s.a.p. Bruce

Reply to
Bruce

Let us know what happens. Usually the pumps either work or they don't, anything is possible though.

Reply to
James Sweet

Reply to
Bruce

Well I spoke too soon on this new fuel pump installation. I had to pull it again to re-soder one of the leads cause I didn't do the job right the first time. ;? ( Bruce

Reply to
Bruce

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