alright, ive had my 7 for a whoppin 2 days now. sometimes it slightly backfires after hard acceleration (slight pop). is this cause by too much fuel being unburned???
also the car seems to run great, but it fluctuates at idle. usually between 1000-1300RPM. any info would b greatly appreciated.

thanx
dustin

 

1. It's backfiring, you are probably running a bit rich. That isn't really bad, better than too lean.

2. You probably have a vacuum leak somewhere, or your LIM gasket is gone/going.

 

If your car is completely stock, you probably have a vacuum leak somewhere, as that idle is too high. Should be around 750-800 rpm.

 

geez, quick reply. i was thinkin vacuum leak too cause when a hose popped off my civic the same thing happened, (irratic idle). what/where is my LIM gasket?

 

Right where you have to remove a bunch of stuff to get at it. Down by the turbos. A real PITA to get to. Stock paper gasket often blows out; Mazda replaced it with a metal gasket in later models.

 

LIM, lower intake manifold gasket??? thats the only thing that sounds right to me

 

correctamundo

 

thank u guys. ill look into a factory service manual soon. so far i love the 7 and the body lines can only b matched by a 66 shelby cobra. its hard to believe its mine ::thumbup::

 

FYI, I had the exact same symptoms, and it was my LIM gasket. Some times the idle would 'bounce' like someone was pulling the throttle up to 1300 rpm then letting off until about 900 rpm and then repeat. There would also be very soft 'poofs' at idle, didn't sound like a back fire but is best described by a poof

 

alright, then i gotta ask. where do u guys buy ur OEM replacement parts???? also in the rear compartment storage area was the 93 FD3 service manual. so ill upgrade all my vacuum hoses. problem is the damn manual has crazy small diagrams. anyone have some online????

 

I hear Ray at malloy mazda has good prices. You should search for his number or maybe someone could give it to you. Also www.mazdatrix.com has a lot of oem parts.

You can find all the manuals at www.iluvmyrx7.com

Also here is a little how-to on the vacuum hose job.
http://www.robrobinette.com/hoses.htm

Another good site with a lot of info for you is www.scuderiaciriani.com/rx7

 

thank u very much once again. everyones been so helpful, thanx again guys.

 

I have the exact same popping noises as 12NV, but mine isnt completely stock (ss downpipe, m2 c0ld air intake, exhaust)

Is popping normal for me as well or do you think I should check for a leak?

 

i also should add that when i turn on the headlights the idle goes steady. so u still think its a vacuum leak???

dustin

 

bump for my last question

 

Check this thread:

https://www.rx7club.com/showthread.p...hreadid=170731

 

Yeah, my 'bouncing idle' went steady when I had the lights on. (Bad LIM gasket)

 

sweet, thats what i like to hear. i guess ill order a LIM in the next week or 2

 

sweet, thats what i like to hear. i guess ill order a LIM in the next week or 2

 

Check your O2 sensor and EGR valve for a low idle as well. The putt is normal..... When you whip an RX7 it will backfire a bit. Cool part is you can sometimes get fire coming out of the exhaust....
EDIT: As for the lights when you turn the lights on the car demands more engine power so it will natarully idle higher. I would belive that the problem still exists.

 

BEWARE, replacing the LIM is not an ideal first FD project to do. I had mine replaced when I had the car for only a few months, and I am extremely confident in my choice to have someone much more experienced do it for me. If you are confident in your abilities and understanding of this car, go for it. If not consider dropping the coin to have someone else do it. Although isn't not cheap to have someone else do it by anymeans.

 

ahhh shoot, i built my very first motor 2 yrs ago (piston engine though) and its still running strong. i have no doubt in my abilities but i appreciate the warning. i need to learn more about the FD but im reading more and more each day.

 

Just an fyi... you have to pull the turbos and whats attached to them... probably your radiator and intake box, upper intake manifold and throttle body, TB elbow, disconnect all the emmissions stuff, unbolt your 2ndary fuel rail, then unbolt your LIM, replace gasket, and hope you remembered all of your connections and placements...

Believe me... before you do it look around and see what all you will have to pull...the UIM isn't that hard (Pull it w/ the TB attached... how many miles are on your car?

 

lucky for me that i have the factory service manual that came in the cars storage compartment. shoot, it sounds like its quite the job though. my car has 108k on it and was garaged its whole life. lucky for me, the first day i had the car i let my gf drive it so as a result it still gets garaged, so now 2 out of my 3 car are in the garage.
well since this thread doesnt seem to b dying i might as well ask, what else should i replace if i have all that crap off???

 

How is you boost pattern? I figure if you have any reason to replace the vacuum lines, do it while you have a majority of the things off that you have to remove anyway.

By the way, WELCOME!!!!!!!