well i have narrowed it down to a misfire under boost when i get into the boost it is bucking and popping. I know it can't be fuel cut I'm only running 5 lbs. of boost. I have adjusted the tps and replaced it along with the plugs and wiresa anyone have any idea what is causing this.

 

Sounds like you are running out of fuel, whether it be fuel cut/pump or injectors.
What are all your mods? Maybe your secondary injectors are not coming on.

 

Holy ****. I just had this happen to me.

 

the only mods I have done is a 3 inch cat back with secondary cat removed and the stock blow off going into the atmesphere.

 

well it could be the stock bypassvalve venting into the atmosphere making it run rich, therefore popping and backfiring.

 

i will try putting it back in to the air intake tube and see if that helps but i had it like that befor it started this. It all started when I put a straight pipe in place of the secondary cat.
Thanks for everyones help.

 

can anyone help me with this. I have tried everything and this is driveing my crazy supose to take it to the trackk this friday but if i can't get this fix i wont be.

 

You check ur plugs and wires to make sure theres no water, or that they are connected securely? Just a guess.

 

You sure you are only running 5 lbs? Sounds like fuel cut to me. Is the restrictor pill still in your pressure sensor line? Even at low boost, you may be getting boost spikes without the pill...thus causing fuel cut.

-Joe

 

does the restrictor pill work both ways, cause theres no indication on the one i got as to which end whould be facing what

 

my boost gauge only reads 5 lbs. there is no restrictor pillow in the line going to the pressure sensor if that is what you are talking about. I was wondering if this cold becaused from the 5th and 6th port not opening but i don't know much about rotary's at all still learning any help would be great.

 

Fitness Stain...I don't think it matters which end its on. It just acts as a narrowing of the pressure sensor vac tube to smooth out boost spikes to the sensor. However, the stock position is a few inches away from the vac nipple on the manifold.

10thanniversaryrx7...If you don't have the little restrictor pill, it is very possible thats your problem. It goes inside the tube that goes to the pressure sensor. Without it, the pressure sensor sees little boost spikes, freaks out, and momentarily cuts fuel because it thinks you are running higher-than-stock boost. You can get one at the dealer, or some people make them. I've heard that little beads for making necklaces work well (get them at a hobby shop). Basically you need something that will go inside the pressure sensor line that is in the shape of a tiny life-saver...seals tight in the line and has a small hole in the center to let air through.

-Joe

 

Check your wires/plugs.

I thought mine were fine, was doing exactly the same thing as you've encountered. Threw in new plugs and wires and it was back to normal!

 

funny this must be a very common problem with a bunch of differant fixes. Mine is doing the same thing and I've done everything besides change plug wires plugs and tps witch is going to be changed out this weekend. Hopefully this will work if not I'm throwing my 7 in the trash jk I couldn't do that.

 

YOU BETTER NOT!!!j/k

 

It seems kind of silly, but have you changed your fuel filter lately?

 

Could be a chipped apex seal. Check your compression.

 

I replied a short time ago to check voltage at all ecu pins, spark plugs, plug wires,tps setting, bac internal seal leak, fuel pump voltage under full throttle up to 12 volts, fuel pressure, and holding pressure. Don't know whether all was checked, but let me relate my story on a '89TII I purchased new:
With about 145,000 miles stock, I was getting this kick back under boost in 3rd/4th gear when under 3/4 to full throttle. I didn't experience this in 1st or 2nd, even under full throttle. It ran/idled perfect. I could run the car to 85/90 with no problem if I "feathered" the gas...meaning nothing more than let's say 1/2 throttle. I explored all the checks that I could do, as stated above, so I took it to KD Rotary. Dave checked all electronics, found nothing in error. Numerous compression tests indicating no problem, however, he could get it to pop in 2nd on the dyno, because of the resistance, and on the road in 3rd/4th. Finally, after about 1 month and a dozen compression tests, a blip came up on the compression test. Front rotor, indicating a stuck, or most likely a cracked seal.
Had the engine replaced with a Mazda remanufactured. Now running 11 psi no problems.

 

that is very unfortunate however I doubt this is my case because when I get the bogging and backfiring my fuel gauge hits zero and then right after wards goes back normal. Fuel cut but I have a fuel cut defender. Do fcd's go out?

 

well thanks everyone for there help. I have finally figure it out. the person I bought it from put some kind of t fitting in the main fuel line and return line that connected them both together so I wasn't getting any fuel pressure. I was amazed someoine would do this. I took it out and fixed then line and now it is great. Thanks again everyone.

 

???? Man that is wierd!

 

Thats a good one.......................