I was just reading Rob's thread Bucking, lack of power on acceleration" and thought I'd post my current stumper. Instead of bucking, the automatic responds with more of a bogging feeling, but to me it is essentially the same lack of power, just with a mushy drive train.

The car in question is a project I've left sitting in my garage for 5 years and just now have on the road. It is a still shiny black sedan, gorgeous leather, and sparkling Coronas that needed just about every repair we ever do to these 240's on the 279K mechanicals. I've given myself a month to shake out the remaining bugs before passing it on as a well overdue gift to my daughter.

Except for a temporary clog in injector #4, the $1.50 gas in the tank from 2003 got me 250 miles with smooth driving, so I felt somewhat relieved when I filled it with modern-day $1.69 fuel. Another 20 miles, and I first noticed the bogging.

It happened only on acceleration away from idle, like leaving a stoplight. Just a hitch, then pulled normally. It reminded me of the little unmetered air you can get when the AMM hose rubs through on the fender wall, but I knew I'd taken good care of that.

Following day we returned home from a turkey day visit riding the last 11 miles of the 110 mile trip in the cab of a flatbed towtruck. We just barely crested a long hill using 4-ways in the breakdown lane before we could find a safe spot for a black car at night. In a parking lot, it got to where it wouldn't even idle unless left to cool for a few minutes.

Before giving up and making the call, I was able to put a test light on the fuse panel either side of fuse 4 to verify full voltage through the 25A and injection relay, and get a hand on the main pump to feel its hum, though if it was making a lot of noise, I didn't hear it over the traffic. After reading Solaris' response to Rob's thread, I regret not resetting the computer instead of just pulling the codes that night.

Naturally, the driver could drive the car onto the flatbed and off when we arrived home, and I could drive it easily into the garage again. And the following day (yesterday) I can run the main pump for an hour without the pressure gauge budging from 45.

That is, until I add the tank pump function. When the noisy (new) tank pump runs, the main pump is intermittently noisy (cavitation) just as it sounds if I pinch the feed hose from the tank sender assembly (new). My thoughts turn to all the threads I've read on defective replacement tank pumps, thinking this is really strange the tank pump makes things worse by running, sitting in 2/3 tankful of fresh fuel.

So, did I knock loose some new gummy stuff from the old gas, or is the almost 300K original main pump worn in some fashion that makes it croak under feed pressure, or like Solaris, did some malfunction in engine management cause the computer to adapt itself right out of the combustion range (113, 231).

I'm headed to the pick 'n' pull this morning anyway, so I'll figure on trying to find a main pump, but when I get back, I'll park it outside and pull that feed hose and play with the tank pump some more to see if I can tell what is going on there. Then re-check the oxygen sensor (it was sluggish) if that leads nowhere. If no other conclusive cause pops up, I'll change the main pump, as much as I hate the parts swap approach. But that's how it goes with intermittents.

It is just a project car at this point, not a daily driver, so I can take my time to find the root cause. Now to get my yard list together.
--
Art Benstein near Baltimore

Marathon runners with bad footwear suffer the agony of defeat.