running really rich, wont rev past 2k when driving

[spydergst16g]

car is a 96 talon, 4g63 pretty stock, other then exhaust and a filter.

its a nieghbours car, so heres the gist, runs like a bag of bolts, wont rev past 2k when driving, super rich, leaves black clouds of smoke like a diesel, no cel.

when hooked up to a scan tool, the o2 reads rich right away, the maf displays 56% engine load (at idle), havent done a boost leak because were under the assumption that the o2 would first read lean then rich, swapped mafs for mine and still the same story. he did tell me he was messing with some screw at the throttle body though in order to adjust what i assume was the idle for emmisions testing or something. anyways this is where were at, i dont really wanna be pulling parts off my car to test because im worried if its an electrical problem it may short out whatever part im gonna lend him. he also mentioned that he pulled off the vacuum line to the FPR for what reason i dont know.

any help would be appreciated.

 

[Lofty]

Sounds like a boost leak.
Check the Intercooler piping.
It could be the BOV too, those suck on 2gs.
I assume he has an air fuel controller.. Right?
And messing with the BISS shouldn't really make these things happen.

 

[No_Skillz]

...havent done a boost leak...

First step - Put the vacuum line back on the FPR.
Second step - BLT.

 

[jusroln]

That is what mine did when my turbo blew. The seals in the turbo went and so it was blowing air stright through the turbo into the oil pan and I was getting oil in the exhaust (black smoke). The turbo was sucking air past the MAS so the CPU increased the fuel but then a lot of the air was leaking through the turbo so the mixture was extremely rich. I could get it up to 3500rpms if I only applied 25% throttle and avoided boosting. Hook up a leak detector directly to the turbo inlet and listen to see if you have air escaping into the oil pan (gurgling sound) or blowing straight through.

 

[spydergst16g]

thanks ill pass it on, the vacuum line was replaced on the FPR right away. no AF controller its pretty much bone stock.

 

[cbr600teardrop]

have you replaced the o2's and check for fuel injector leaks black smoke most of the time is fuel look and see if some orings are bad on the injectors or if any of the injectors are stuck open that would definitely cause that problem

 

[spydergst16g]

well the o2 readings on the scanner seem to be accurate as to whats being spit out, but of course thats not gonna last long till it gets clogged, ill check the injectors but all cylinders are running rich.

 

[DSM90AWD]

Car may be in "limp" mode due to a prior MAF issue. Try pulling the (-) cable form the battery for 30sec to reset the ECU and see if that helps.

Also check that all hoses from the MAF to the turbo inlet are airtight and that the BOV return line is routed back to the intake

 

[cbr600teardrop]

if all are running Rich then i would say cts you should have two that communicate with the computer then maf but you said you tried that is the fpr gone bad some times the can leak back into the intake threw the vacuum line and a scan tool said the computer was OK

 

[spydergst16g]

sorry whats cts?

 

[cbr600teardrop]

Coolant temp sensor

 

[kimbsy86]

jusroln have a ? on what you said. Hate to babble on but just bought my 95 gst 3wks ago, deal is my car wont rev past 3k and will stall if the accelerator isnt being pressed down. Think it was blowing a lil smoke to. Deal is the motor and everything sounds great, took it back to the dealer i bought it from ( they dont know crap about these cars ) and they said mechanicaly the motor and drivetrain are great, they are thinking its electrical. my ? to you is could it be the seals on the turbo or do you guys also think it is electrical? if so what could be the problem becasue wiring and electrical issues arent covered in there 90 day 3000m warranty. I feel so SOL

 

[98DiamondStar]

Get that Catchcan off of there kimbsy , you said it's welded shut, when i had the car there were two small filters on the top, which let that crank case vent out, now it's just building pressure. When the pistons try to come down, theres a huge ammount of resistance. and i'm sure the smoke is coming from that pressure pushing out on your valve seals. Just my .02, call me anytime on this information. Also, the only thing electrical i can think of thats going to make it do this is, like stated above from 08' the coolant temp sensors, the car thinks its cold when it's not, BUT, the MAS will make it do this as well, i unplugged mine just to see, and it wouldn't idle, it just died, a full swing from 0 - WOT in park was really rough, but it did go past 3k. Get it checked out.

 

[kimbsy86]

its 2am my time for ## info Alaska, but yea i will remove the catchcan and drill her out. its a nice setup but doesnt seem to be to functional unless i mod it out with some power tools ( whoever put that on, , but it beats me ) And i have no idea where to begin to look since it has the 6bolt swap, my repair manual seems to be almost useless for wiring diagrams now. who knows maybe if i get some sleep ill be able to think about something other than my dsm and all electrical components that could be wrong. o2 sensor, CAS, MAS, Knock Sensor, PMC, ECU, Faulty connections, No connections, ugh... who knows, I was going to get a FFWD 6 bolt race motor next yr with my tax money after the construction season and work on it myself ( I.E. put it in wire myself ) but it has a 6 bolt, just wish i did the work so id know everything about it.

 

[Calan]

Get that Catchcan off of there kimbsy , you said it's welded shut, when i had the car there were two small filters on the top, which let that crank case vent out, now it's just building pressure. When the pistons try to come down, theres a huge ammount of resistance. and i'm sure the smoke is coming from that pressure pushing out on your valve seals.

I'm guessing Kimbsy didn't realize this thread is over 2 years old, but regardless...I think you guys may want to read this:

http://www.dsmtuners.com/forums/articles-engine-fuel/366890-4g63t-pcv-system.html

 

[98DiamondStar]

Okay, I read your write up on the pcv, don't quite understand why you posted that on here. Very detailed write up though +1 on it, will be using that later on if I see anyone with questions relating to the PCV system.

 

[92AWDHX40]

Thats a great post up there discussed the vacuum system and emissions.

 

[Calan]

Okay, I read your write up on the pcv, don't quite understand why you posted that on here.

Because I read posts that mentioned welded catch cans and drilling them out, huge amount of resistance on pistons, etc.

 

[98DiamondStar]

Ohh, yes yes, of course. I thought you were correcting someone. It's never good when you have a catchcan ment to have a filter (or two) and they are gone and welded shut. Leads to blown valve seals, blown dipsticks, it's just ugly.
I would like to find the one who did that to my car after I sold it, totally redick. They also removed the evoIII16g and put a 'factory' turbo on. tsk tsk, that evo3 only had 300 miles on it.

 

[hypergenesis]

im having this same problem could it be due to a faulty BoV?

 

[96pos dsm]

im having this same problem could it be due to a faulty BoV?

yep 2g bov's are no good

 

[98DiamondStar]

Yeah, be carefull what you upgrade to though, theres plenty of aftermarket BOV's that are just as bad. I'd suggest running a 1g BOV, depending on your boost leve, you can always crush it.