This started about 3 weeks ago.
Is this an indication that the gas is not beeing completely burnt? Could this be caused by bad Spark plugs (I changed them 6 weeks ago), or bad ignition wires (haven't changed them for 2 1/2 years - 30,000kms)?
How often should you change ignition wires?
I've also just had the main cat removed and got a straight pipe installed in it's place (can anyone say loud ), but the popping started before this. I've also had the pre-cat gutted (about 1 year ago).

I'm also having boost problems (this started about the same time as the exhaust popping). You can hear the boost, you can see the boost gauge go up, you just can't feel it. This happens most of the time, but occasionally, I do get proper boost. Any Ideas what this could be?

 

Sounds like you need a fuel controller or hal tech.You are running too lean.But you will get a loud pooping noise after fixing the fuel system because of the lack of cats at wide open throttle and shifting.Thats because unburned combustion in the exhaust will ignite from building up.

 

sounds like he's running rich to me...not lean

 

Correct me if I'm wrong, but wouldn't running 'lean', mean I'm not getting enough gas? Since my fuel economy is crap, I'm going to assume that I'm running rich.

Anyone else?

You beat me to it.

 

1. Are you relying on the stock gauge or an aftermarket?

2. How many miles on the turbo?

3. Do you have a blow off valve?

4. Have you checked your engines compression lately?

 

1) Stock gauge. I know they are unreliable, but I've never had any problem with it. As I said, I can hear the turbo spooling, it just doesn't seem to be getting into the engine.

2) I have 133k KMS on the odometer. I don't race, and I've never pushed it very hard.

3) Everything under the hood is stock, so if it didn't come with one, I don't have it.

4) I had it checked about 10 months ago and was told it was good (but the ******** at Mazda never gave me any numbers).

Question... does the car need to be running for a proper compression check (at Mazda Dealer)? I mean it idles, but ummm... let's just say it's a little funky. (all vacuum hoses were replaced 6 months ago).

 

Honestly, if they didnt give you the numbers Id be surprised if they actually did one.

 

It wouldn't surprise me.

Noone else has any thoughts??

 

try adjusting your throttle postion sensor and mess around with the rich/lean screw. helped on my car. by the way the popping on downshifting is normal for rotaries but it shouldn't reallyy do it at idle. have your engine codes checked also, the car might be running in safe mode for some reason

 

If you hear boost but don't feel boost, you might have a boost leak.

The stock gauge doesn't mean spit once you mod the car at all really, especially if you have a fuel cut defender.

Popping on decel is normal when you're running rich and have an open exhaust, it's a hair shy of shooting flames.

 

I was thinking boost leak too, but I don't know from where?

I will get a boost gauge, and I think I will also need to get an FCD.

 

Hmmm, where is the rich/lean screw?

 

Passanger shock tower next to the boost sensor.

www.egauges.com has good priced gauges, maybe give them a look.

 

hmm.. be very carefull with the rich/lean screw.. Mark the factory position before messing with it.

get a can of brake cleaner or carb cleaner and look for vac/boost leaks.

Quesions:

What RPM is your idle set at?
Have you checked the TPS lately?

 

Hey StarionX, if it helps, i have a 89 tII in ottawa too and i have the same shatty *** idle/popping crap as you. Minus the boost thing... i'm thinking that's because you're boosting before the car is fully warmed up. And i do mean FULLY. Because the ecu will be in the cold idle mode, and it will run like a bag of **** since its so damn rich.

Give me a shout, we can diagnose our **** together lol I already set my tps ... and re-checked it like 3 times (made sure the car was hot. In fact, burned myself trying to do it several times)

Good luck.

 

Ummm, the idle is a bit of a touchy subject, but at the moment, it hovers around 1000 (most times).
TPS?? No, haven't quite gotten up the courage to tackle that. I'm waiting until this part of the world realises it is supposed to be spring, not winter!!

 

You have email.

 

i have pretty much the same problems. I also have low idle sometimes too...
I know i need new plugs, but the overall problem can only be a few things...

TPS can be off, you(me) can have a vacuum leak or a boost leak somewhere, or you can be running too rich like myself.

But like someone said, be very careful playing with the rich/lean screw. BAD THINGS CAN HAPPEN WHEN YOU SET IT INCORRECTLY.

I also have a clogged cat i believe, and that can be screwing up the boost, as soon as i can, im going to get my highflow cat thats waiting for get welded in at home installed...along with a complete look over for any leaks and a tune up...Its only a matter of narrowing down the potential problems.

 

Do the TPS already, guy!

http://home.rmci.net/panther/tps.htm