matthewpims

Ok, my problem child se has finally taken off into the twilight zone. Some days, actually in a matter of minutes the car can go from idleing absolutly perfect to a rough stumble. Ive tried everything, all new sensors, all readjustments, sometimes its fine, other times it sounds like a cam'd out 408, Also with the tps hooked up, it back fires constantly on engine brake above 3k, w/o the tps the car is faster and doesnt backfire... wtf! The sensor tests good and ive adjusted it and readjusted it etc etc, ive been playin with the damn thing for a month now, im all out of ideas, Oh and with the raw idle adjust screw all the way tight it still idles at 1100 which means I have a vacuum leak somewhere in that 1/4 rubber hell-Im loosing my patience, ill just gut it all and put all new **** in there when I put in the new engine I spose, ever get that way?

KehoeAutomotive

Did you test the TPS? The fact that the car runs better without it makesme want to look closely at that.

Hold the gas pedal to the floor and see what the voltage is. (5volts?) is it reading 1.2 volt closed? 2.5 volts at half throttle?

When it is running back do you get and backfiring out the the exhaust or intake?

Vacuum leaks don't tend to come and go. But defintely look for one.

Backfiring out of the exhaust i would look closely at the ignition components. They came come and go like a switch. I've had several RX7's come in with ignitors failing doing similar problems.

Good luck.

RacerX7fb

Has the entire upper and lower intake manifold/dynamic chamber/throttle body ever been removed and had a thorough cleaning ever?
Do that and change the manifold to block gasket, since this is the one that is usually damaged upon disassembly and put new vacuum hoses... good time to ungum the 6 port sleeves and have the fuel injectors sent out for a cleaning while youre at it. Clean all electrical contacts associated with the above. Reassemble everything then retune. If the airpump has been removed (for headered use or whatever) try reinstalling it as well.

matthewpims

car is stock, 6 ports stuck wide open, the tps is good but misadjusted im sure, it backfires out the tail pipe along with 6 foot red and green flames, not to mention the ocasional glowing bit of muffler baffle. The intake mani has never been removed to my knowledge, but who knows, im puttin a new engine in it this spring anyway but its just annoying, it could very well be that my igniters are goin out, is there any way to check them?

Steve Shulz

Warm up the car and Ohms check them, specs are in the manual, I doubt its your ignitors. What about timing? Check your TPS (easy check). Run MMO through it (1oz per gallon).

matthewpims

Timing is perfect, the omp is shot so I have to premix 1oz of mmo pergallon have been doing it for 3 or 4 months now. sad part is I drove well over 1000 miles in 90+ degree heat w/o and omp because I was ignorant to what it was or did at the time, and I know it did damage, thats why im building a new motor for the car

Steve Shulz

If its stumbling you should be able to see it with a timing light hooked up (find out if its your ignition) and listing you may be able to hear where its arcing from. What happens when you disconet the BAC valve then reconect it?

matthewpims

Nothing happens, as far as I can tell there is a vacuum leak somewhere, bad one too, when the car idles where its suppose to, below a 1000 rpm it idles perfect, when the car idles above 1000 it tries to throw ign advace to it and it misses, every time, all the time, thus its not an ign problem. or it would miss at any idle speed. When I unplug the bac nothing happens unless I have like the lights on or something. Right now the state of my car is as follows: The tps is unhooked, along with the idle air/fuel sensor, which I think is faulty (nothing happens when its plugged in or disconnected). When I plug them in the car idles the same, (around 1200, and rough) and the only different is throttle response is a tiny bit better, the downside of having them plugged in is the car backfires and shoots 5' flames when engine braking, and seems to lose upper rpm power 3k+. so go figure