breaking up bad after 3500 rpm!! and idle at 900 rpm
 

My car has always idled at 1400 rpm, now I'm lucky if it idles at 1000. The car pulls fine until you reach around 3500 rpm's and then ist breaks up realy bad!! first gear is fine and then after that every gear breaks up after 3500. The only thing I have done recently is disconect my air pump, it burnt up, and I was told that you could just disconect it and it would be fine.. When it comes to the car breaking up I thought it was ignition but I put a brand new pair of laser plugs, and it is still doing it...any clue:wallbash: ???

year:1993
Twin turbo

laser plugs? what are those? Use NGK plugs.

normal idle is 700,

whats breaking up mean?

For starters Laser plugs are made buy NGK they are there platinum line.

And as for idle not My car, mine has a large street port and other work, it has never idled at 700, and I have two other friends that have fd's that are almost stock and they don't idle at 700... So any help would be good thanks guys!!

Even with a large street port and a ton of other mods there is really no need for an idle above 1k, I like to set them at about 1100 rpms with all accessories on and they will usually drop to around 950 with everything off. Enjoy the lower idle and dont worry about it, after disconnecting your airpump any fd will idle a little different.

Have you replaced your coils or igniter? What about plugs(dont say I just replaced them 3-5k miles ago) they can foul out in 10 miles or less.

No have not replaced the coils or igniter, And no just replaced means last night. and it is still breaking up past 3500, and the low idle does not sound healthy, It seems like a vacum issue, or ignition... But I checked all the vacums and the ignition... still no clue..:wallbash:

I have a Primary coil for sale in the box. Paid over $160. for it let you have it for $100 shipped.

Clogged cat owing to disconnecting the airpump?

Have you thought about the LIM gasket?? My fd had the stock cardboard one in until it failed recently!

The symptoms that I had were twofold,1. Vacuum leak at idle and 2. higher than usual idle.

I was not getting anything like the same power on acceleration and sometimes just as I came off the gas I would get a strong smell of fuel.

Putting a new LIM gasket on solved all those issues!

If you have taken your air pump out and also have a port job and then a blown gasket id imagine the idle could be all over the place imo.

And I presume by breakup you mean a massive flat spot in power on the gas?

Just a suggestion!

Thanks man, I may have to get that from you, I just want to test mine to even see if that is it.

And by breaking up I mean spuddering and popping, like turbo detonation

Check your primary coil first.

I'll check my primary coil today

maybe I missed it, but are you running a PFC? I would think so since you mention the large street port.

If so, what are your boost settings on it? What are you actually boosting to?

does it only happen at full throttle or during any load?

With the blown LIM gasket I was getting loads of spuddering and popping aswell.....maybe this is because when you accel air is drawn in but you could be getting too much air due to a blown gasket...the ECU sees all the air and dumps fuel to prevent lean condition, so you end up with loads of unburnt fuel spuddering and popping/igniting in exhaust!!

Ok next dumb question, what and where is the LIM gasket?

O and I still have my air pump, it's just disconected

The LIM gasket is down low on the passanger side of the engine...the turbos bolt to the LIM and the LIM bolts to the block (I think)....get some carb cleaner and spray it down there near the turbos and if it effects your idle you could have a leak (blown gasket)....also search on it here or on my username and you will find info.

This is just a suggestion, to replacethe LIM gasget you will have to take out the downpipe and turbos to get at it!! Itsa big job to say the least so you would want to be sure before starting into it!!

AFAIK the LIM gaskets used on all RX7's up to 94 were all cardboard and will fail at some stage....but if your car is 95> it will ahve a metal gasket tht should not really need replacement!!

Yeah mines a 1993!! so I'll check that when I get home!! thanks bud, I'll keep you posted

Well you better tell them that there is a problem with their cars because the FDs idle is 720rpm, (800 with A/C).

Its written on the underside of the hood!:lol: :lol:

Why not reconnect the airpump up and check if it fixes the problem

Don't got out and buy coils or gaskets just yet. I have the same issue. It started at 4500rpm, then at 5500 rpm. I had 2 very well known rotary shops go through the car with me and several rotary guys as well. Here's what is comes down to; no one has a clue what the problem is. I have posted it on here and no one has come up with anything that cured the issue. The last thing I tried was upgrading the ground wires for in the engine bay. I put everything back together, and now the car wont start. Again, many informed rotary guys have looked at my work and gone through the trouble shooting. Everything is hooked up right. All parts are new, or in good shape. I have air, fuel, and spark. My compression is good. It's the damn rotary gremlin living in my car. One day it will just start up after I change the wiper blades, or something totally unrelated to the motor starting.


I know I ranted a bit. But, just make sure you KNOW what is causing the problem before you spend the $ on stuff that may not be the issue.

Best of luck. I will PM you if I locate my gremlin, please do the same.