1980 Stalls Upon Accleration
 

I'm new here. I'm original owner of 1980 RX7. Two weeks ago while driving on surface streets, I accelerated from stop sign and car stalled. Upon restart, it let me drive about five minutes and then stalled again upon acceleration. It did this as I limped home: restarting, driving OK for a few minutes, and then stalling upon acceleration. Drove it yesterday for first time in two weeks and after 15 minutes, same problem: stalling upon acceleration, then restarting, then stalling upon acceleration.

Any ideas? Fuel pump? Bad gas?

just guessing at this since obviously i dont know your car but.... check your catt on the car.... if the checks out (personally id remove it) then do a compression test... maybe apex seal(s) sticking or broke... my guess anyway...

Fuel filter, spark plugs?

Text book symptom for a fuel starvation problem. Most commonly caused by a clogged fuel filter or fuel pump problem.

Thank you all. I checked fuel filter and it looks clean. It seems to me that if the fuel filter were bad, then the problem would be constant and it's not. Haven't checked the catt or compression yet. After checking around locally (Los Angeles) I found a Mazda tech who is highly recommended. He's got the car now (only stalled twice as I limped it over) so I'll let you know what we learn. His from the hip guess is a carburetion problem although I'm not ruling out fuel pump problem. It sure acts like its a fuel supply problem. Thanks again and stay tuned.

Stock fuel filters, even when new, barely flow enough to feed the carb. Get just a bit of anything in there, and you'll start starving it if you outrun the fuel flow. You'll be fine just cruising, because you can squeeze enough through the filter for that, but once you step on it you'll run the float bowls dry.

Hopefully the mechanic doesn't screw with you, and simply replaces the $4.00 filter. Good luck....



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Thanks for your comment. Even though the filter looks clean, we're going to replace it as a first step. The symptoms appear to be fuel related so, as you noted, the filter is a cheap and easy potential fix. I should know shortly.

the consensus seems to point to something related to the fuel or fuel supply. The gas I put in the RX7 is the same gas that goes into our other cars and there's no problem with them. We'll see if a new fuel filter solves the problem. Thanks for responding.

January 3 update:

Encouraging news followed by bad news: The RX specialist at the dealer (Santa Monica Mazda; my private Mazda specialist retired years ago) reported the problem was solved; all it needed was a good cleaning of accumulated "gunk" in the carburetor. I was dubious but excited. I picked up the car and it stalled again six blocks from the shop. I limped it back where it sits today. They tell me they have escalated the problem to the Service Director. I'm not happy.

Be careful before you authorize the work. Dealerships are crooks.

Things off the top of my head:

1. Fuel filter
2. Gunk in carb (maybe good cleaning, probably rebuild)
3. Intermittent connection issue to pump
4. Trash in gas tank getting sucked up against intake pipe (will usually restart within a few minutes).


Good luck. If you need a rebuild, check back before you pull the trigger. There's a guy on the forum doing great rebuilds at very low prices...

I appreciate the advice. I went for many years to an independent Mazda specialist on the westside of LA but he closed up because there were not enough cars to keep him in business. We put a rebuilt 12A in the car about eight years ago and, until now, it ran perfectly.

While I share your concern about dealers, I have worked with this one before with good results. I make sure I meet the tech who is working on the car. Because the car is in perfect shape, they usually treat me and it very well. It's not like the see a car like mine every day.

They want to do a test drive with me because they reported they warmed up the car and drove it around for ten minutes today without a problem. We're going to drive the car together tomorrow or Thursday.

Thanks for the advice about finding a specialist on this site. It's one of the reasons I joined.

BTW, I've put premium gas in the car for the last 10+ years because I wanted no issue with CA's smog check tests. I'm told that should not create the problem I'm having.

Thanks again for writing. I will keep sharing what I learn.

If it's not the carb it's a fuel delivery issue, i.e. pump or line

To all who were kind enough to provide advice:

The problem was with the carb, aggravated by some other issues. We checked fuel filter, fuel flow, solenoids, compression, etc etc. After eliminating everything else we could think of, we rebuilt the carb and replaced some old items at the same time (eg, distributor, plugs, wires, etc). Car now seems to work fine although I just picked it up yesterday. This weekend will be the real test.

If I learn anything else, I'll share it.

Many thanks again.

So far so good. To those who wrote recently about dirty fuel, rust and fuel filter, we've run flow tests, pressure tests and replaced the filter just for the heck of it. Does not appear to be problem with fuel or fuel supply. Rebuilt carb plus replacing some other old parts appear to have solved problem. Due to LA traffic, test today was truncated but tomorrow we should know for sure.