I've had my FC now for about 2 months. Aside from the oil seals being gone (I uses a gallon of oil a week almost) it's been an alright car.

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It's a 1986 Rx-7, I'm not sure on anything other than that.

It is a 5-speed

13b n/a
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The problem with the car is after about an hour of driving (normal driving) it starts to cut out once I reach 3000-4000 RPM.

It starts at about 5000 RPM and gets progressively worse, sometimes so bad it cuts out below 3000 RPM.

After reading Icemark's FAQ post, I checked my grounds, cleaned them, and secured them back.

I was told that the corrosion around the bolts on the actual motor is from it overheating. I bought it from a mechanic who had no idea what he was doing and sold it due to the original owner not paying a bill. I don't know anything about the car's past except for a few receipts showing basic upkeep purchases.

I'm hoping it's not to big of a deal since I'm planning on finding an S4 13b turbo to swap in when I get the money, however, until then, I would like to have the car running since it's an extremely fun car.

So to recap what I am posting about in case I lost some of you:

1986 RX-7 n/a (5-speed)

Cuts out at 3000-4000RPM once it warms up (it starts jerking and refuses to accelerate)

Only does it after it's driven for 45m-1hr, or has been driven kind of hard.

 

Here is an extended grounding writeup:
http://www.aaroncake.net/rx-7/grounding.htm

Wow. Just, wow.

Anyway, after checking the grounds as shown in my writeup, test the TPS while the car is both cold and warm. Also, check the boost sensor on the passenger shock tower. This is harder to test, so it may be easier to just swap in a known good unit from another car.

 

Thanks, will check those 2 sensors.

As for the corrosion around the bolts, were they right? Wrong? Just wondering because once I get my new motor I was going to tear into this one and try to become more familiar with it. If it's not worth trying my hand at rebuilding I would like to know before I go spending more money.

 

The statement doesn't make any sense at all. Saying corrosion on bolts is somehow related to an overheated engine is ridiculous. You said it yourself, the mechanic you bought the car from had no idea what he was doing.

 

Ah, well I'm equally mechanically challenged, so I guess we'll hope for the best.

 

I take it that you mean it runs poorly and loses power under acceleration, once it has been driven for 45min +; I assume that it runs ok at cruise?

The temperature related nature suggests: water thermosensor, intake air temp sensor (AFM), intake air temp sensor (plenum).

At power suggests TPS.

Check for trouble codes, and verify closed loop operation. If those are ok, look to see what the rich/lean flag is reporting during the problem. Under acceleration, it should be rich all the way up. If it goes out (lean), that suggests the bucking is due to going too lean under acceleration.

The rich/lean flag (also called the 'monitor lamp', or the 'green lamp') is the bottom center pin in the green 6 pin test connector. It goes to ground when the ECU sees a rich condition, and it goes high impedance when the ECU sees a lean condition.

 

In the end, the whole problem was caused due to lack of back pressure. The gaskets on my exhaust were falling apart. Took getting stranded to figure that out >.<

 

Did the problem go away? Because the engine does not need backpressure to run. You can disconnect the exhaust system and drive around no problem (aside of making everyone deaf).

 

make sure that the plug that plug into your injector is pushed on all the way..at least thats what fixed it for me when i had that problem..

 

If you need anymore help on it I am local. I'll send you a PM.

 

Can you elaborate on this? I'm betting the problem remains unfixed.

 

Is the car running ok? fixed?

 

A GALLON OF OIL A WEEK!!!!!!!!!!!!!!

hahahahahahahaha, dude really?!?!?... I think the gallon a week is your problem.... or do you mean a quart

 

make sure your wires have a good connection on the angle sensor.. i think thats what it is lol. looks kind of like a distributor. mine was doing the same thing. it was acting like it had a rev limiter at 3k-4k rpms. i unpluged it and pluged it back up made sure it was nice and tight and it fixed it. also make sure your plugs, wires and coils are in good working order.

 

Lol nah, I was using close to a gallon a month, needed a rebuild...BAD.

As for the current situation, the car is hopefully going to end up in Rotaryinspired's shop for a bit for a TII swap.

 

sounds like blown motor