Help! Could this be a simple fix with my GST??

[sepulchral]

im a newbie just purchased a gst today with an evo 3 swap, and its running really rich, has check engine light.. when i let cylinders clear out it boosts fine and pulls hard, but after a while the engine floods. I just got it today at a really good price, and I was hoping you would have any knowledge on this problem..

could it be o2 sensor?

its a 1995


*Car runs rich, fowls plugs often
*Car has check engine light on
*Car has idle 1200-1500rpms
*Car randomly sputters or i'm guessing gets flooded.. If I let it idle, the cylinders clear out

* 50% of time car goes into full boost 14lbs and pulls hard and strong

Car runs super rich


I'll try to take it to a autozone, but does anyone have a good idea what this could be? I doubt its boost leaks.

 

[importboost]

boost leak test it

 

[sepulchral]

i really dont think its a boost leak.. it holds 14lbs strong on a t25... when its not flooded.

 

[K_Hill]

Like importboost said do a boost leak check..

http://www.vfaq.com/mods/ICtester.html

 

[sepulchral]

why are u so convinced its a bboost leak? i'll try and boost leak test it i guess. i really doubt thatswhat it is.

 

[K_Hill]

Ok.. Is the BOV recirculating back to the intake? Is the MAF hacked? What is the gap on the plugs? Does it have larger injectors? Does it have a 255 without a Fuel Pressure Regulator?

 

[sepulchral]

bov - atmospheric, NO adjustable FPR, what is a MAF Hack? Dunno gaps on plugs but what should they be set to?

 

[andymoraitis]

How about doing first things first and having the codes pulled at your local AutoZone? CEL's come on for a reason and yours may be directly related to your issues. Once that's done, let us know what the scanner says and we'll be able to guide you.

Andy

 

[spooling 1g]

plugs should be gapped at .028

 

[sepulchral]

will do, thanks andy

 

[andymoraitis]

No problem! I just want to verify that the code isn't triggering the issue before we start with boost leaks tests and plug gap issues. Drop us a line after you find out what the code was and for reference, you can find a list of all trouble codes below. I hoping it's just something like your front O2 since that's any easy fix, but we'll soon see.

http://www.dsmtuners.com/forums/showthread.php?t=191516

Hang in there!

Andy

 

[K_Hill]

Recirculate your BOV and that may fix it.. With the BOV vented to the atmosphere causes the car to run poorly. Was the CEL on when you bought the car? But from reading what the problems are and thinking about it it does sound like the o2 sensor has gone bad..

Yes, Go to auto-zone and tell us what codes the CEL is throwing.

You need to update your vehicle profile so later on if you need any help its there for the people to see it.

 

[sepulchral]

ITs walbro 255LPH
OBD I Ecu that comes with stock 1995 GST

hopin they have a autozone up here in west virginia

 

[sepulchral]

the retards at autozone don't know where to plug the scanner in, where do you plug it in to check for CEL codes???

 

[redeclipse7782]

Underneath the dash on the drivers side, next to the side of the center console.

 

[FORMONTOYA]

OBD I Ecu that comes with stock 1995 GST

Actually 95 is OBD2.
Jim

 

[travislaw]

ITs walbro 255LPH
OBD I Ecu that comes with stock 1995 GST

hopin they have a autozone up here in west virginia

Do you have an AFPR (Aftermarket Fuel Pressure Regulator)? If not there is your problem. Your Walboro 255 fuel pump is putting out way more pressure than the stock fuel pump does and therefore you will run pig rich.

 

[andymoraitis]

Bingo. FPR overrun will kill performance and foul the plugs. The greater danger is that you're washing fuel past the rings and diluting the oil. Either add the AFPR or get a 190 in the car. Also, despite the fact that the lack of an AFPR is an obvious issue, the CEL light still needs to be read. The scanner hookup is on the passenger side under the glove box.

Andy

 

[EclipseTrbo420A]

why are u so convinced its a bboost leak? i'll try and boost leak test it i guess. i really doubt thatswhat it is.

The reason is because, Your t-25 will be working twice as hard bringin in more air than it needs to, to hold 14 psi. So now your have your MAS reading 100% of the air being brought it. Your losing 20% of that out of the leak. Now your ECU gives the amount of fuel needed for all the air that the MAS saw before some leaked out, but since your leaking out 20 % of that air theres 20% more fuel just being dumped in to your motor. Its good to do a boost leak test even if the cars feels ok. I do one once every 2 weeks.

Not to mention the 255 with out a regulator. DSMPARTS.com has a bolt on fuel pressure regulator for the 1G and 2G's, but im not sure what fuel rail you have.

 

[dsmgrimreaper]

change the plugs and wires, go with ngk plugs and 8mm wires and see if that fixes it, ive had many boost leaks and it never flooded the engine out, ive had bad plug wires and that did. make sure the your not venting cause that can cause it to but they dont normally idle that high when your venting

 

[Strm Trpr]

Do you have an AFPR (Aftermarket Fuel Pressure Regulator)? If not there is your problem. Your Walboro 255 fuel pump is putting out way more pressure than the stock fuel pump does and therefore you will run pig rich.

I believe an AFPR (Adjustable Fuel Pressure Regulator).