Ok, so lately my rpms have been stuttering uptop and going crazy. I started to try to fix this problem by changing the fuel pump to a supra one... no difference really. So now this leads me to think its the fuel filter? My car has 136k miles on it and I think the filter was probably changed ONE time ( yea, yea). I only got the car 4 months ago with no real history on it.

Next problem....

When i first got my car it would boost up to 10 psi no problem . Lately I have been noticing it only going up to five and holding steady there. I dont know what the deal is... can this be related to the fuel problem i'm having? Oh yea, I have the stock turbos with 136k miles on them. And blue / white smoke DOES come out on a cold start up.

 

Based on the first part of your description, I was going to suggest you check your secondary fuel injectors. I was thinking that one or both were stuck closed. The second part of your description, however, suggests that you have a leak in your intercooler plumbing somewhere. Check to be sure the rubber parts are not torn or split, especially the short hose flange at the top of the y-pipe.

 

Thanks, I will check both.

 

Wait since i'm a noob to rx7s, what and where is the y pipe?

 

Does anybody have an idea of where most boost leaks occur? I looked all over my motor yesterday and didnt see any hoses off or loose. Where is the y pipe at?

 

It's the pipe that is shaped like a Y.



(the one that connects the two compressor housings together and connects to the crossover pipe to the intercooler)

 

From the bottom of the intercooler, follow the hosing back over the top of the engine (from the front of the car it is angling to your left). The pipe across the top of the engine is black if that is your car in the picture. The end of that pipe has a 90 degree elbow pointed downwards. Attached at that point is the critical rubber hose coupling. Splits and tears are hard to see sometimes so I suggest that you pull it off and deform it and stretch it to be sure there are no splits. BTW, the piping just below that hose coupling is the infamous Y-pipe. You should also check to be sure the nuts securing the Y-pipe to the turbo housing (follow each branch of the Y down) are tight as well. That is another common source of boost leaks.

 

Thanks, I checked those hoses and they all seem fine. I did however notice a beat up and tore up brown hose running along the back of the firewall. Could that cause a boost leak?

 

Yes, I think you are talking about the hose that feeds the accelerated warm up system and if torn could be letting boost escape out through the tear. Does the hose hook into the back of the intake elbow just ahead of the throttle body?

 

Another question. Mazda just changed my fuel filter ( hadnt been changed in 136k miles!!!) but the car still acts choppy. He said the injector is messed up from the bad fuel filter but will eventually clean itself out with the help of injector cleaner. Does this make sense?

 

Only if it works. With 136,000 miles on the injectors your lucky they haven't started to leak (externally that is). In any event, if they do not clear out you will probably need to send them out for cleaning. BUT, if you are going to all that trouble, I would suggest you consider putting in all new injectors. The originals are notorious for leaking fuel after the century mark (and causing fires) and the newer, upgraded versions have better plastic molded caps that will stand-up better over time. Also a good time to put in larger injectors (and I would recommend only enlarging your secondaries) if you plan to step up your hp down the road.

 

This is what the hose looks like, [img]//images.google.com/images?q=tbn:KSBdfK_UJ0sJ:mysite.freeserve.com/www.vintageaqualungs/reg22.[/img]

It seems to go into the block of the motor , hoses is on the passenger side firewall. It is VERY torn up and has holes in it.