Just bought the car and noticed some sort of popping sound from the exhaust pipe when I start it up and rev a bit. No matter if it's hot or cold. sounds like backfire or somthing.

Here is a vid on the car
http://www.youtube.com/watch?v=e8MfZe1zLkY

Is this really normal?

The mods on the car.

3 inches exhaust from the turbos.
Open air filters.
Atmospheric bov.
Removede Catalytic converter
And remaped for this spec.

 

Well since it sounds like you are running an open exhaust, the popping you are hearing is just unburned fuel getting burned up on its way out of the exhaust. Normally the catalytic converter would take care of the unburned fuel. It means you are running a little rich, which in a rotary is a good thing. If you really rev it up, you might be able to get it to spit flames!

 

given your mods. Yes it's completely normal

 

mine does the same thing, but the intake, engine and exhaust are stock.
I assume that is not normal?

 

Aha okey. If i put on a metalic converter do you think that the backfire will stop? Btw do metalic converters work on our cars?

 

be careful of boost creep if you are running stock twins. Most the time when the midpipe is removed the car will do this and its good buy motor.

 

Do a sensor check my car used to do the samething and it was the water temp sensor, sometimes it was reading 4 sometimes reading 100 as a result it kept over fueling but sometimes under fueled when it was reading warm when the engine was cold. Anyway it cost me and engine.

 

A catalytic converter adds a lot of restriction to the turbo system. If you are tuned to run with out a cat, and it does not break any laws in your country, I would do it. It should make much more power than with the cat. I am not sure what type we use stock I will let someone else chime in on that.

 

This is not necessarily true -- a rich fuel map causes the engine to run hotter than a lean fuel map. How many miles are on the engine, how many miles on the injectors ( are they stock? you could potentially have an injector that is sticking if they have excessive mileage on them ). Who tuned the ECU for that setup? What ECU are you running?

When you are not boosting, you want your car to be running as lean as possible without it impairing the power ban / throttle response.

Do you have a wideband AFR gauge ?

 

6990 miles, it says on the meter. do not know if the engine has been rebuild in the past but i doubt it. think it is standard injectors on it but not sure.
standard ECU, written 99 spec on the ecu with ink pen.

http://www.wgtautodevelopments.co.uk/
has done the remapping of the car.
On the receipt from the company that I got with the car it says "ATTN to apexi carry out mapping" If it helps.
Do not have a AFR. but do you think I should buy one?

 

What year is this FD and did you buy it used? 6,990 seems like an awfully low number even for an FD produced in 1999.

Your running a pretty free flowing setup on the stock injectors - what boost levels are you running?

I highly recommend investing in a wideband AFR gauge (PLX / AEM make affordable and reliable ones), I would also recommend you get an aftermarket oil pressure gauge & water temp gau

 

If you are near that shop where you got the car I would take it to there and have them diagnose the issue for you. It should not be popping like that after such a small rev

 

Sorry forgot the last number. It says 69909. Made 1996
Don't know the boost level on it. The boost gauge didn't work when i bought the car so have ordered a new one. have to come back on that info when i install the boost gauge.

 

The shop is in UK and i live in sweden so that would be a problem hehe

 

So your driving a 96 Rx-7 that allegedly has less than 10,000 on the clock.

Either the cluster was swapped out or you own an incredibly MINT car - what did you pay for this vehicle?

Have you run a vin search on this car?

Regardless, I would go ahead and get that boost gauge fixed so you can see what kind of vacuum your pulling, get a wideband AFR gauge, water temp gauge and oil pressure gauge.

Then you will at least be able to pull some basic diagnostics on the car.

 

69909 miles = 112507km
is quite a lot, In my opinion.

 

http://www.wgtautodevelopments.co.uk/
I think you need to speak to pip at wgt ,Im sure he will sort it for you. As he is very Trustworthy person.And one of the best rx builders in the uk.I doubt he would of sent it out bad.There are very tight laws in the uk so you will have some come back if you need it.Rix.

 

Ok!!! That 69,000 makes more sense -- I was going off your initial post a few posts up where you must have had a typo stating 6990 miles.

I would go ahead and get the gagues installed - I am curious what your idle AFR's are.

 

my cars got an unrestricted exhaust and intakes and i do quite a bit of backfiring. multiple people have reported seeing blue flames in my exhaust - it dosent worry me.