hhn2002

few days ago my fc died on me out of no where. showed little sign 10seconds before shutting down. then towed home. need a reliable daily driver and this isnt it as i've come to sadly realize. anyways something is up with my primaries, below 3800 have have to keep on the throttle just to keep it from dying and acts as if i am blipping the throttle but i am not. above 3800 it shoots to 4300 ish and acts completely normal. super stable. i know what you guys are thinking. YOUR PRIMARIES ARE CLOGGED! very plausible but then i switched primaries for secondaries since they flow the same CC stock(im right arent i?) still same symptoms but may have gotten just a tiny bit better. ohh yea around 2000 **** backfires like no tomorrow(well a bit over exaggeration but you get the idea). added twice recommended dosage of techron fuel injector cleaner; helped considerably but still wont hold idle for ****. not enough to drive it to the local auto care center for fuel injector cleaning. i dont know maybe its because i've swapped out ignition coil, fuel pump, and secondary fuel rail/FPR going crazy for the past few days trying to figure out what the hell is going on. then there is this semi high pitched sound that sounds almost like a supercharger that also gets louder with the rpms. its driving me nuts cuz no one can figure out where the hell its coming from. again i know what ur thinking - "sounds to me like a big ******* vac leak"
its never done this prior to the breakdown and i havent touch anything. i mean i rebuilt the bitch alittle over a month ago. you wanna know something else? its still in its breakin period with just under 1500miles! hells up with that?! i treat it to a nice refresh and still the bitch wants to get temperamental with me!

i dont know i guess this is just my fc blues bitching thread.
after this is all sorted out im putting it up for sale and getting a mid 90's impreza awd. im a poor enough college student as it is.

peace

Icemark

Compression? (I bet you haven't checked and if you did that it is low)

Have you checked for a vac leak? (I bet no)

Who rebuilt the motor?

The lack of real info makes it difficult to help you... year? make? model? Spark plug condition?

And finally:
Why would you drive it somewhere for fuel injector cleaning? To clean a fuel injector you need to pull it (which sounds like you can do) and send it out to be ultrasonically cleaned.

hhn2002

91 s5 vert 140k miles.

nope i haven't check compression, cuz it doesnt seem like it would be compression issue related though i should for ***** and giggles(been curious anyways) like i mentioned car is completely fine when the secondaries activate.

i've removed mid intake manifold and upper and am pretty sure they're on tight and check all hoses.

i rebuilt the motor my self with the same rotor housings. (not recommended i know but should still work, keep in mind im not aiming for power for any stretch of the imagination just rebuilt before factory apex seals blew on me) also removed all emissions. havent gotten around to getting block off plate for ACV so its still on there completely disconnected from anything. yes i've also tried blocking off the openings where the old air tubes went and still didnt get rid of the noise. also removed all belts including alt for a while just to rule out a bad accessory or belt.

spark plugs are less than 5 thousand miles if even that. swapped spark plug wires around with no effect. though i'd probably need new ones but i doubt bad wires would cause sudden failure.

well quite a few shops around here as i know it do fuel injector cleaning with them still in the car only(ie running purely concentrated solvents through fuel rail under pressure) though surely not as effective as off-car injector cleaning. i think i may have found a place somewhat nearby that might do them off car so ill check it out tomorrow.

really i appreciate the help icemark but the rx7 was just a phase, though i dont think i could have gained experience working on cars any faster any other way; it's made me a mechanic(shady tree maybe but still valuable either way) when two years ago a piston ring was a new concept for me. thanks

djmtsu

iTrader: (3)

Exactly. Sounds like a vacuum issue or just some really shitty injectors.

djmtsu

iTrader: (3)

Doh!! You posted quick. The ACV is pretty hard to get airtight without removing it and using a block off. I really don't think your FC needs much to get right.

If not I'll give you $700 for it!!

DREYKO

I really think its a vac leak. they arent as obvious in high rpms.
the noise is coming from your front passenger side brake vent, theres an air pump in there, or it would be the same vac leak. I cant hear it so i dont know.

Slow Rotor

Going from an fc to an impreza is like dating a supermodel and dumping them for a whale dont do it man

Icemark

You didn't answer my questions on spark plug or vacuum test.

Condition of the spark plugs means you need to pull the plugs and give an accurate description of what they look like. Are they wet, are they all carbon'd up, are they melted?

And you will need to do a vac test. Get the car up to run at a steady speed (someone may need to hold the accelerator to do this) and spray some automotive starter fluid (found at most auto parts stores and even walmart) around the intake runners and throttle body under the hood. If the RPM increases at all while this is being done, then you have a vac leak.

and have you checked the TPS for operation, correct calibration, and clear of any faults?

and I would question the ability of any sort of fuel injector cleaning that didn't remove the plugs and ultrasonically clean them. Solvents will never do more than a 50% clean job.

dazed01

Everyone with a rotary engine should know the compression of their engine when it's hot. Not warm, not hey I drove it around the block, but operating temp. That helps with a lot of troubleshooting. Talk to your local mazda dealer and you should be able to get one pretty cheap. I imagine they would charge you anywhere between free and .5 hours for it since it's so damn easy on a fc. Rx8's on the other hand kind of suck unless you have it on a lift.

hhn2002

its got 80% of the symptoms of a vac leak but that doesnt explain how it got mysteriously and considerably better a little after i added fuel injector cleaner in the tank. but you guys are probably right.ill do a close inspection of my lower intake mani cuz that was the only one i didnt remove and retighten. and yes i will also do the starter fluid test. thanks for the suggestion ice.

yes spark plugs will be checked also. tps will be last since its sounds like a pain the but to do. but i haven't ever done that b4 so we will see.

hhn2002

HOLY **** BATMAN YOU GUYS ARE RIGHT! DAMN I FEEL LIKE A DUMBASS POINTLESSLY ARGUING THAT IT WAS INJECTORS! sorry for being so hardheaded i tend to do that alot. i found the huge vac leak. it soo stupid im embarrased to say where(lets just say it was on my lower intake manifold that was the size of a pea,lol). it was all my fault when i went to assemble the engine, and i was in such a rush. only had like 2 weeks notice to finish up b4 we had to move. im a person that likes to take time. **** im sorry you guys.
my sincerest apologies to icemark for trying the hardest to help such a noob. really thanks for your time. im going to go kick myself in the butt now.
ohh well case closed/solved
thread locked lol.

hhn2002

700 bc of a vac leak!? UP YOURS! haha jk

dammit maybe now i can convice my mom to let me keep it.lol she hates sitting in my car. it smells(gutted cat), shakes alot(bad wheel bearings and insufficient exhaust hangers), and obnoxiously loud(low level muffler made by flowmaster)

on that note does anyone know of a good muffler besides stock that can produce stock like quietness?(single side exhaust/single muffler or in series) thanks