rx82000

Hello

I own a 1984 RX7 GSL with a 12a engine and do not have many modifications on the car. Living in Montreal, I do not have to worry about emission so I don't have any cats.

To the point.

At around 6000rpm in third gear, I can't get any more power from my engine. While the pedal is to the floor, my car seems to stop accelerating and will start to make a weird noise with erratic engine movement. It's not the intake or exhaust that is causing this problem. The compression seems OK with 75 (x3) psi for the front rotor and 85 (x3) for the back rotor.

Is this problem more likely related to fuel availability or is it related to my ignition system or worse is my engine done?
Thanks for the comments

damon

sound like it starving for fuel

1Bad85Rex

try replacing the fuel filter, I had the same problem that all but went away when i did that

peejay

Replace the fuel filter about every month or two.

Those are the exact symptoms of a clogged fuel filter.

If that doesn't solve it, you fuel pump is hosed.

SilverRocket

I had very similar symptoms last summer caused by a broken trailing sparkplug on the rear rotor due to detonation from experimenting with timing settings. Before anything else check your plugs to see if they are all intact. I would have a close look at your whole ignition system; bad coils could cause the problem you describe.

It could just as well be the fuel stuff, however my experience with fuel filters is that your car will stall and stop running with no warning - I've never experienced any such problem as you describe from a filter. I've had a few fuel filters quit on me very quickly and unexpectedly. I'd run a few tests to see how healthy your fuel pump is. There's a volume and a pressure test described in the Haynes manual.

(of course replace the fuel filter to rule it out, and if it solves the problem so much the better)

crazy dog

Fuel filter sounds like to me also

Pittdp

I have the same problem around - 6 - 6.5k I am going to have my fuel pump looked at soon. I have already changed the filter

rx82000

Thank you for the replies;

Here is my list of action for this weekend:
1- Replace fuel filter
2-Find out how to check my coils (I've checked all the spral plugs this week while doing the compression test)
3- Mesure the fuel pressure of my fuel pump

How do you check your coils on a 12a engine?
I have the hanes manuel, I'll check when if there is a description or you guys with rotary expereince can give me a link or a few pointers.

peejay

I doubt it's the coils.

What happens when the fuel system is crapped out (due to bad pump or old fuel filter) is the engine works okay through the first gear or two. The fuel system isn't keeping up with demand, but the engine runs OK on the fuel in the float bowls. Eventually (typically halfway through 3rd gear) the carb simply runs out of fuel and the engine sputters.

The first time this happened to me, I was racing. First gear - goin' good. 2nd gear - catching up! 3rd gear - PUUUHHhhhh.

A good test for this is to get it to happen, then let off for a few seconds, reducing the fuel demand and allowing the carb to fill back up again. Floor it again. If it has good power for a few seconds, then it's the fuel system. Most likely the fuel filter. This happens to a LOT of people. In the future, replace the fuel filter every couple months or every oil change, whichever comes first.

rx82000

I've had the same fuel filter for the pass 50 000 km
(30 000 miles) .....

If this works .... I'll be happy

peejay

Holy crap! That filter is probably a solid chunk of crud by now. Yeah I'd say it'd be your problem

SilverRocket

After seeing that I'm bettin on the filter too - I can't believe you've gone so long on the same one! I change mine every 5000 kms or so.

rx82000

Problem solved!
Thank you very much even if I should of thought about my problem before stessing about it for such a long period of time.

I don't remember the last time I went 160 km/h
(100 mph).

Can you adjust the "play" in your steering wheel?