cveklund

I had just posted earlier about how to make the car backfire, and I think it did when pulling into my driveway. I was not trying to make it backfore this time, and never have before, and I cut the car off thinking I had enough speed to get into thew driveway, and I didn't, so I hit the gas a little, fogetting that I had cut the car off already, and POP. It wasn't a very loud pop or anything but a little one. Then I restarted it to get it into the driveway, and the car would barly run, then died. So I started it again and gave it some gas and it got me up the driveway, but ran like ****. It sounded like mad exhaust leak with the sound fo forcing air. I hope this makes sence and sorry about the log post, but I am a little worried about my car.

Thanks,
Chris

85RX7GS

iTrader: (1)

When you rev the engine does it stumble very slowly up to 4k? Does it seem like you have half the power that you had before?

cveklund

Yes, it kinda stumbles up there and then kinda smoother. I just took off the first cat and am leaving the manifold open, kinda like open headers. It is louder that **** but still stumbles, so what do you think?

Chris

cveklund

Anyone have any clue?

Chris

nelam

It will not be related to the cat. If the cat is plugged up, you can still start the car and it will idle just fine. But when you take the rpm higher or drive the car (with some load on the engine). Then the car will stall because the exhaust has no way to get out and choking the engine.

You took the cat off and the car still stumbles at lower than 4k, hence it is not cat related.

I hope this is something else than an apex seal.

cveklund

I can't really tell if the engine is still stumbling until tomorrow because it it getting late and my neighbors are pretty old and will call the cops if I try to run the fricking thing. I hope it isn't a seal either.

Chris

xxxHondaGuyxxx

Sounds like you blew a hole in the cat.....and flooded the engine.

My cat has an OBVIOUS leak, and I get this crazy whoosh of air sound. Like a harriet jet when I rev it up.

If you're saying you drive, and then turn the car off as it is coasting suddenly, you are dumping in fuel, which does not get ignited. My dad used to get a kick out of that with an old van he drove....until it blew apart his muffler, and the van ran like crap afterwards.

What you're doing might sound crazy, and be fun to play with, but it causes damage. The car would stumble because of loss of backpressure if you have the exhaust separated at the header. Like I said, my cat is junk, and just leaks like a sieve. If I dont rev it high enough from a stopped start to take off, the car will sputter and die on me. Imagine trying to shoot a bullet out of a gun, with a crooked barrel.....and you'll get the picture of what that does to your exhaust.

Keaponlaffen

um.... sounds like a blown apex or corner seal to me.... backpressure won't change the way the car accelerates... if it stumbles and sputters and feels like it has half the power... it has half the power... I would bet a toasted seal, or an ignition problem... but seal is my best guess...

Suparslinc

I guess you could have blown a seal from the backfire. I think its more likely that you some sort of exhaust problem, that you are just now noticing. However, it could still be a blown seal. I blew an apex seal just coasting up to a stop sign. The wheels locked and she was toast.

damon

do a comp test and make sure you get three equal spikes on each rotor

cveklund

I don't want to sound like a complete idiot, but how do you do a compression test and where can I get the tool for it?

Chris

mar3

iTrader: (8)

Has your coolant level started to drop? I lost my first '79 12A to a backfire that took out the "O" ring that runs around the housings...course there was a lot of white smoke to tell me the obvious as well....so, never mind...

cveklund

I havn't started it today as it is raining. When I would drive it before this happened, I thought there was very little smoke, not sure what, but I am going to try to find a compression tester and check that first. Do you think Autozone or another parts store has a loaner one so I don't have to buy one or are the really cheap? Also, where is a good place to get one and what kind/model and number should I look for? Also, is it ok to run the mototr for a while with open headers? And to do the compression test, do I have to have the motor warm, or can I just plug in the tester and crank it for a few seconds?

Thanks for all the help,
Chris

specRX7_22

the motor should be warm. this gives the apex seals time to expand a little so you can get an accurate reading

cveklund

Ok, thanks. Does anyone know where to get the meter from and the part number/type?

Chris

EDIT: I also need to know about leaving the header
open.

Thanks,
Chris

Pedestrian X

just go get a regular old compression tester.. dont tell them its for a rotary tho .. or you could jsut take out the plugs one at a time.. and listend for 3 even "pooshes" from each rotor id do that first actually.. and after that if you are stil nto sure then go buy a compression tester.. they are handy to have aroudn anyways.

cveklund

Thanks Pedestrian X!

Does anyone know about running the engine with no exhaust?

Chris

Suparslinc

Its okay to run with your cats disconnected, but running straight exhaust from the block (without a manifold) is dangerous. You will shoot flames and might burn your engine bay.

Keaponlaffen

cveklund

Thanks sooooooo much for the help. I still have the manifold on and it looks like it is going to be clear enough to warm it up and do a compression test.

Thanks,
Chris

RX71982

hey i have an 82 Rx-7 that bckfires like hell and doesnt want to run and i feel alot of power gone. ive changed the fuel filter and checked all of the vaccum hoses (i think =) checked my plugs and wires got spark all around but my idle is still low and crap and my power is crap and my car backfires.....like.....well crap. what all do i need to check to find the problem.