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engine fires up, hits 2k rpms, and then stalls

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Old 08-01-08, 03:42 AM
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NY engine fires up, hits 2k rpms, and then stalls

I am unable to get my RX7 running right now and I'm unsure why. It was working perfectly well one after noon and the next day it stopped running.

When I attempt to start the car, it fires up without problem. The engine fires, the car hits about 2,000 RPMs and then it stalls.

Nothing I can do from behind the wheel has changed this outcome. It doesn't matter what I do with the throttle, it has no impact on anything.

Any ideas?
Old 08-01-08, 05:32 AM
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Could be unmetered air entering the throttle body. Check the AFM connector, check for leaks after the AFM and check all the clamps on the air intake pipe.
Old 08-01-08, 06:12 AM
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Fast check : try with the Fuel pump initial coupler (will force power to pump). If ok then it's an AFM problem (fuel pimp switch).
Old 08-01-08, 07:13 AM
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maybe fuel filter is clogged up and not letting the fuel threw.
Old 08-01-08, 07:22 AM
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I think someone said it but, make sure the afm is plugged in.
Old 08-01-08, 08:58 AM
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+1 on checking the AFM. Car should crank, attempt to idle, then stall out almost immediately.
Old 08-01-08, 10:52 AM
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I'll go out there and report on the findings this afternoon.
The fuel pump and fuel filter have less than 500 miles on them.

I recently purchased the car in Vermont, after it had been sitting dormant for over a decade. Towed it back to Florida, got it running with a very modest amount of work, and now I just towed it back up to New York. It was running when I put it on the dolly well. But I had to roll it off the dolly after getting it here because it wouldn't start.

I'll check the AFM and the air system... I impulsively was thinking along the spark of fuel direction, but the AFM makes a lot of sense. Thanks.
Old 08-03-08, 12:56 AM
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....quick question:

1987 Mazda RX7 Turbo II

Where specifically is the AFM? I'm in the middle of a cross country move right now and haven't come across any of my manuals or service material yet.
Old 08-03-08, 01:18 AM
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Originally Posted by Calabrio
....quick question:

1987 Mazda RX7 Turbo II

Where specifically is the AFM? I'm in the middle of a cross country move right now and haven't come across any of my manuals or service material yet.
its the thing the air filter hooks on to. left hand side of engine bay.
Old 08-10-08, 03:42 PM
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I'm stumped on this one.

I pulled the trailing pulls, turned it over a couple times to make sure it wasn't flooded.

Then I replaced all the plugs. They didn't look too good, so i figured I'd start there.

I inspect the air intake and can't find anything visibly wrong with it.

The car continues to fire, then die.
And it was running fine before I towed it, and once I got it here, I had to roll it off the car dolly.
Old 08-17-08, 04:44 PM
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I'm still unable to find the problem and the car is still unable to run.

The fuel pump is moving fuel.
The sock filter on the pump is clear.
I just replaced the fuel filter again.

I can find no disconnect connections or bad fuses.

I'm stumped here.
Could this be bad gas? Is there any way to use a scanner or check for codes on this car? Any advice still appreciated and needed.
Old 08-17-08, 08:16 PM
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Like was said before, this sounds EXACTLY like when my AFM was unplugged.

That metal thing under the air box is the AFM, there is a black plug that connects to it, make sure it is plugged in all the way and the AFM is working if that doesn't work.

To check the afm, pull the air hose off and make sure the AFM moves freely.
Old 08-18-08, 02:48 AM
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Failed AFM?

Originally Posted by Malefoda
Fast check : try with the Fuel pump initial coupler (will force power to pump). If ok then it's an AFM problem (fuel pimp switch).
I had a very similar sounding problem. It turned out to be a failed AFM. The internal circuitry went bad, so it would not tell the fuel pump to run. The symptom only ocurred if the engine was cold and the air was cold. Any other time, it acted fine. Yours may have failed differently, but the problem may be sporadic. How did you test that the pump is flowing? If you used the procedure posted above, here's how to check the AFM.

After the car starts and dies (just to be sure your problem is happening): Open the intake airbox, take out the air filter and prop open the AFM flapper (a screwdriver works pretty well) Turn the key to 'on' position and go to the trunk. Listen for return fuel splashing in the tank. If there is no fuel, then the AFM is not sending the correct signal and you need a new afm. Do not jumper the fuel pump coupler while doing this test. If you are getting fuel, it may be a botched fuel pump rewire or large intake air leak. Hope this helps. Good luck.
Old 08-18-08, 06:01 AM
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I had the same issue after installing an aftermarket filter. I currently have that little hose (which I believe is the AFM) hooked up to a breather completely separate from the actual intake. After removing and reinstalling everything the exact same it's all fine. I truly believe it's an issue with a loose cable. My tach stopped working, so I remove the trailing coils, blow out the plugs and reinstall it and it works now.. These 21 year old plugs are so annoying..
Old 08-18-08, 08:21 AM
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I am 99% sure that everyone that is telling you it is the MAF is right. You need to check that again... Seriously...
Old 08-18-08, 02:33 PM
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I had earlier checked for loose connections and found nothing. But this afternoon, I removed the air filter housing and examined the AFM closely.

The flap moves freely, it's not obstructed.
But I don't think it's working.

I had someone start the car for me while I manually pushed the assembly open. The car came right to life. As soon as I let go of the part and the valve closed, the car started to stall.


Does this mean I just need to replace the assembly with this part:
A-1 CARDONE Part # 749107


It's an '87 RX7 Turbo II, but it was bought in April of '86.

Last edited by Calabrio; 08-18-08 at 02:40 PM.
Old 08-18-08, 02:45 PM
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Well in this case you must have a vacume leak in the intake hose which mean the air is not coming through the AFM at all.

Check the intake and make sure there are no missings hoses or cracks ect.
Old 08-18-08, 04:54 PM
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And that was it.
The AFM was still good, but there was no pressure opening it.

While I'd looked to make sure that everything was securely pluged into the intake itself, the problem was one of the hoses properly secured to the AFM was leaking. The large one that heads down towards the turbo.

Once I repositioned that and tightened up the band, the car ran brilliantly. And it's an absolute dream to drive this car on the mountainous roads around here. A pleasure, sometime infinitely more fulfilling than I'd previously experienced driving in Florida.
Old 08-18-08, 05:00 PM
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Sounds like your AFM is working. The flapper should not shut all the way when the engine is running, so it sounds like you have unmetered air bypassing the AFM. Check the intake hoses and connections. Especially the small hoses from the underside of the intercooler. They're on the passenger side near the firewall. They are very easy to overlook. If you don't see anything, prop open the AFM, let it idle and start spraying starter fluid on the connections until you find the leak.
Old 08-18-08, 05:08 PM
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Glad to hear you figured it out! those simple things are what always gets you (i spent a whole day trying to trace a fuel problem, when the whole time i was just out of gas, so don't feel bad.
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