Tommg

1985 GSL-SE, 108,000 miles, all original.

1) After the car warms up (not overheats), it loses all engine power. It will restart but doesn't have enough power to move the car. After the car sits for an hour or so, it operates normally. Plenty of power, etc. I have noticed that there seems to be excessive pressure release when you open the gas tank filler.

2) The car intermittently hesitates.

Both of these problems started after the car sat for a couple of months, and both problems have begun to occur quicker and more often. I have replaced the fuel pump (twice) and filter, Air Flow Meter, Pulsation Damper, and tuned it up. The Mazda dealer is working on the car, but doesn't seem to have a clue, and I am not prepared for them to start replacing parts until they get it right. I am the original owner of the car and have never had any problems in the past.

Any suggestions?

AdrenalifeRX7

Try changing the oxygen sensor.

Tommg

Thanks, Adrenilife!

The Oxygen Sensor is on the EFI Unit, correct? Wouldn't the dealer's scan of the computer chip indicate a faulty sensor?

From reading all of the O2 sensor archived posts, it seems that the sensor is also related to the exhaust system. I recently had an aftermarket exhaust sytem installed. Could this also be related?

Thanks again.

AdrenalifeRX7

From my experience, most O2 sensors on on the exhaust manifold. They come in single wire O2 and heated O2 versions. I'm not 100 percent sure though as to where it is on your car. Locate and it change it. If it's the single wire sensoor it should be a hell of a lot cheaper than a heated unit. Just start small and work you're way up until you solve the problem. Maybe they forgot to hook up something when changing the header and/or downpipe when you had that aftermarket system installed.

AdrenalifeRX7

Oh I forgot to add..the sensor should look something like a spark plug threaded into the exhaust manifold. Make sure the manifold is at least 150 degrees F before you attempt to change it because if you don't it can be difficult to remove and possibly you might damage the threads. The wire from the O2 should be clipped to a main wiring harness and is easy to detach.

AdrenalifeRX7

And yet another thing...change them spark plugs while you're at it. Make sure you get NGK!

Tommg

Thanks again, Adrenalife,

The dealer INSISTS that it can't be the O2 Sensor. Maybe the markup on that part isn't high enough for them. I just replaced the plugs. Any other suggestions?

Tom

12abridgeport

It sounds like the problem that i have. You might be loosing your compression after the engine warms up.

Tommg

The dealer is now saying that it is the AirFlow meter and the Catalytic converters...does that sound reasonable?

Tommg

After a MONTH at the Mazda dealer, 2 replacement fuel pumps, 2 Air Flow meters and then saying that the cat converters were the problem....I took it to Ortiz Speed shop who took an HOUR to say the fuel tank was rusted. Replaced it and it runs like a top!

Hopefully this will help someone with a similar problem.

poweRX-7

i think the real problem here was taking it to the mazda dealership in the first place!!! but glad to hear you got it runnin
jeff

enigma32

Why would a rusty fuel tank cause those symptoms?


Glad you got her goin'!

poweRX-7

i am going to guess that the rusty fuel tank was messing up the pump... seeing as how the dealership replaced the pump twice, in a one month period was it?

Tommg

According to the Speed Shop, the GSL-SE fuel tank has an internal screen that clogged BEFORE the fuel filter or fuel pump. The dealer kept replacing the pump because they are idiots.

Incidentally, over the years Maz dealers have been pretty good until now. Even so, when I called the General Manager to complain, he refunded my repairs without hesitation, split the cost to have the car towed across town, and gave me a new fuel tank at cost. Fortunately, the RX is a spare car for me.

851stgen12a

Well Damn!! Glad that worked out for you. I was actually getting pised, up untill the last post.