Misfiring/stuttering

[99GSX_emily]

I did some searching in the forums search but I couldn't find the answer i was looking for really. I have misfiring when i hit about 20psi in 1st & 2nd gear, & you can see a puff of white smoke comes out the rear! In 3rd & 4th gear its almost impossible for me to hit anything past 5psi, it feels like I'm stuttering like it wants to hit boost but can't! I checked the coil (14.80ohms on 20K ohms setting), plugs (gapped to .028), wires & they were fine plus I've replaced all of them about 8,000miles ago I would say. Boost leak's I've taken care of but Imma test that again tomorrow when i can get my hand on some air! I DO NOT have a APR which i know would make me run pig rich, but would that cause my issue?

But, back to the white smoke, would a blown head gasket have anything to do with misfiring? I do have some overheating issues but only when I'm using the a/c with boost, but no real signs of a bad gasket. And lastly, CEL is useless, it's has been on since i've bought the car. (code comes up as a bad fuel sensor in the tank & o2 sensor of course)

I'm runnin 99 GSX, big16, FMIC, 255lp hp pump, & I&E. Is there something else I'm missing? Thanks for the input!

 

[99GSX_emily]

Are you sure this isnt Fuel Cut and not just a stutter/misfire? 20Psi on an E316G will almost certainly give you fuel cut.

Go read post #22, misfiring isn't much of my problem anymore, mostly fixed by turning down the boost. I had fuel cut then put in a 255hp pump which after that then the misfiring started but i was pushing 20psi on stock motor which would explain the misfiring in my mind so i lowered the boost. Now i just have this random oil spitting/leak.

 

[boostNmetal]

Glad to hear the car is running better.

I believe that may be what you were seeing (fuel cut). Turning down the boost would certainly cure that.

As for the oil leaks, that sounds like an unrelated problem.

Have you done a compression test? It sounds like you have ring blow-by and, consequently, high crankcase pressure.

 

[staztrx250]

Glad to hear the car is running better.

I believe that may be what you were seeing (fuel cut). Turning down the boost would certainly cure that.

As for the oil leaks, that sounds like an unrelated problem.

Have you done a compression test? It sounds like you have ring blow-by and, consequently, high crankcase pressure.

I'm still going to go with bad turbo seals I would get that turbo off asap. A blown turbo may boost just fine that doesn't mean it's not blown. But if you keep it on you're either gonna seize it right up or the bearings are gonna go to hell and you'll loose a turbo wheel.

Once you get a boost controller just put a t in you're bov vac line. Go from there to the MBC and from the MBC to the waste gate cap everything else.


Did this oil leak start after you changed the vac set up?

 

[99GSX_emily]

Have you done a compression test? It sounds like you have ring blow-by and, consequently, high crankcase pressure.

The compression for piston #3 & #4 were at about 65psi, piston #2 was around 37psi, & piston one was around 55psi. Quite the difference, I'm sorry i gotta ask ### i dunno, but whats the stock compression suppose to be? 150psi?

Once you get a boost controller just put a t in you're bov vac line. Go from there to the MBC and from the MBC to the waste gate cap everything else.


Did this oil leak start after you changed the vac set up?

Yes, The oil leak started when i changed the vac line to go from the BCS to a "T" then the "T" went to the WGA & the lower intercooler pipe. So your saying run a vac line from the BOV "T" to the MBC & then to the WGA? What about to the intake? Just plug that up too with the LICP?

EDIT: So stock compression is suppose to be 178psi i see....so all my pistons are completely off , is there anything else that would cause low compression besides, head gasket or rings?

 

[99GSX_emily]

Got home from work today & did a wet compression test & my specs came out to 140, 130, 125, 130 (#4 - #1) from what i know if the wet test is a noticeable different from the dry then mostly can say my rings are bad. Now I'm pretty sure i do have high crankcase pressure, especially under boost since that's when oil decides to spit out everwhere, which i just gotta hunch is from a floating valve (which means the piston probably is beat to hell & back too then) or a bad head gasket. Either way, the only way to find out but taking the head off unless y'all got anything i missed???

Now the body's got 140,000miles on it, it's an automatic, & probably gonna need a rebuild if it's not just a head gasket....to rebuild or not to rebuild will be my question?

 

[boostNmetal]

Might as well rebuild if its in the budget. 6 Bolt swap wouldn't hurt either

 

[Chazz1978]

Well how are you getting 20 psi with stock injectors no tune and no fpr. I would try to drop boost some. Or have it tuned. Definately go over all ic piping and vacuum lines. Thats alot of boost with no mods. Head gasket would smoke idle and on throttle so its likely not the problem. Yeah posible rings but would be blue smoke not white. White does posibly mean coolant. It just may be head gasket.