please help getting frustrated...Missfire/idle/smoke

[95strandedDSmR]

okay guys ive been working on maintence last few weeks trying to get to the bottom of this goofy idle. When i bought the car it had a very slight miss every once in a while and bad idle surge. I found loads of boost leaks at the throttle body gaskets, shaft seals and biss valve seal. I replaced all those seals got just about every boost leak solved other than the 2g bov that leaks a little. Thats one of the next things I tackle.

Now the problem is, it never smoked before at idle but now its missfiring very badly at idle in park and the idle never sits still its constantly flopping around sometimes high sometimes almost to a stall. Adjusting the biss doesn't keep it from almost stalling at all and helps in no way with the missfire. Ive tried 3 sets of plugs including ngks, 3 sets of wires. 2 coil packs. Ive replaced all of the injector seals.

The car now smokes black smoke as if its running rich assuming thats from the missfire not burning all the fuel in the cylinder. I ordered an IAC motor to put on...but I don't see how that would solve a missfire...maybe an idle surge though. As far as the missfiring...where should I go next and what should i replace/check now... please help... im down to this car as my only car atm. If your in pittsburgh area and know DSMs well..i would appreciate any help...i love the car...and want it fixed.

 

[Lusion972]

Have you checked your cas? My car smokes now but thats because of the valve stem seals. I would say you have a bad sensor some where...while the car is running unplug and plug the sensors one at a time to see if it makes a deference. Thats how I track down sensor failure...if nothing changes after you unplug one then that may be your issue.

 

[95strandedDSmR]

gotta find out how to check the CAS. Will search up the process on that. Do u mean the Camshat sensor? or the crankshaft sensor? Just got finished opening the ECU to see if there was any problems inside. Found out its a 95 5sp turbo ECU in my 95 Auto Turbo talon. Auto / 5speed ecu wouldn't make a difference would it? I have the 450cc Injectors in the car so it shouldn't be struggling like it might with the 390cc I know it does in hondas...but I think these cars have there own TCU. I have tried unplugging sensors like the TPS, and IAC and MAF. Both the TPS and IAC show no reaction when I unplug them. Odd thing is im getting spark on all of the cylinders and when the engine dies down...the spark slows down aswell...almost like it sounds like its missfiring but I don't think it really is? Its jus extremely rich in fuel...an smoking greyish/black smoke. Blah its overwhelming. I ordered an IAC im praying that makes a difference.

Also does the IAC normally make noise? or should it be silent? When the rpms drop drasticly on one of its annoying 100 rpm dives I swear I can hear the little motor buzzing sometimes. I just don't want to go and install the new one and be let down again

Could an IAC motor cause black/grey smoke out the exhaust?

 

[Lusion972]

ecu's can be swapped between auto and manual...apparently your car an ecu failure before. I know you said you checked the ecu, did you check the underside? Some times damage can be found under the processing chip and you cant even see it.

Spark dies down because the engine slows down which is causing the alternator to provide less power. You should order a factory service manual and test the IAC and TPS prior to just swapping them out. They could just need to be reset. It can make some noise, like a little electric motor zipping back and forth but not be to loud.

 

[95strandedDSmR]

ECU appears to be clean and damage free, top and bottom. Wish I knew someone with a 95 ECU to swap with real quick... can't afford to just go buy one. Did learn though that my ECU is EPProm or w/e which will be nice in future.

Boost leak test goes upto 20 psi bleeds down to about 10 psi an takes quite a long time to bleed off from there. ###### well over 3 minutes. Good or bad?

Okay did a compression check today...gave me a little relief. This is a cold compression check and the numbers were
Cyl 4 Cyl 3 Cyl 2 Cyl 1
180 195 185 195

Those i believe are some pretty good numbers. These pressures held solid aswell...didn't slowly leak out at all Which should tell me that the valves and rings are sealing well right?

Last thing I need to check is the physical timing. Neone know how I can get the motor to rotate without having the car up in the air to line up the cams? Im a bit hesitant on using a wrench on the cam bolts to do so. If the timing is on, that would take the internals of the motor out of the picture right? Which might cause me to just go an pull the entire intake manifold off, regasket everything and install all new vacuum lines. Just hard to do out in this torturous cold we been having.

Neone in pittsburgh area that could help me threw adjusting the TPS, IAC and Biss correctly would be greatly appreciated once im done doin all this. Any further tips though are appreciated.

 

[nyTalonTsi]

How did you get those high of compression numbers? A stock 7bolt motor has 8.5.1 compression pistons where a fresh or healthy cylinder has 178psi.

I can tell you this, a tired crankshaft sensor would cause alot of misfires and stalls also make the car smoke.

Thats the issue i had with my first 2g. It would always misfire and stall smoke all the time. Till i found out the crank was hitting the crank sensor.

You can rotate the motor using a wrench on the cam bolts, just make sure you turn the motor clockwise. Just don't force it.

 

[95strandedDSmR]

The head has been shaved, and number 2 piston was supposedly replaced aswell as the rest reringed an honed. Valve job has been done aswell..so I imagine that would have something to do with the high numbers. Just can't figure out the rest of whats going on...I let it crank for aobut 5 compression strokes and those numbers held solid...

Its really wierd..when i first start the motor the first 5-10 seconds of it running, it doesn't misfire at all..but as soon as it tries to drop the idle down where it should settle it starts to fall on its face an bounce around. Going from a honda to a DSM...is hella tough...but im gonna stick it out. The crank and cam sensors both require removal of the timing belt huh? this is a 95 so i know the cam sensor is behind the cam pully. Hate to pay a shop to do this work...but having no garage leaves me stranded with little choice.

 

[nyTalonTsi]

You know thats the same exact way my old 95 acted. Especially when it was fully cold, start it up and then it would sound normal then like less then a min later it would start to smoke and sound like it was cammed.

Check on that crank sensor. Is it throwing a check engine light?

 

[95strandedDSmR]

Thats exactly what its doing, its progressively gotten worse in the last 1.5 months i had it. When i bought it, it sounded like it had a very slight miss, but i was told thats just the vibrations from the Bshafts being removed. But obviously thats not true nemore .

nope no check engine light. Last CEL i had was evap solenoid, swapped it out hasn't been back since. One time like 3 weeks ago it threw a random misfire code...but cleared it an it hasn't been on since. But it runs so bad now, Im very scared to drive it, as it just sounds terrible and just runs like crap. Another odd thing is, even though its holding boost...the vacuum at its best on idle before the problem escalated, would never get any lower than 11-12 and bounced around a whole lot when in drive at idle. Boost guage boosted to about 11 held.

And sorry for my noobness, is there any easy way to check that sensor or will I be removing all accesorie belts and timing belt?

Okay guys...I just installed a new IAC motor today to see if it would effect my problem/symptoms. After installing the IAC I started the motor up and now the idle is high...updwards of 2k. No matter how I adjust the biss or move the tps, It will come no lower than 1500. If I unplug the MAFS the idle comes down but still tends to miss.

I cleaned the MAFS out with MAFS cleaner. Didn't seem to make any difference. Could a bad MAFS cause the engine to missfire, idle high, and run rough? Unplugging the MAFS oddly seems to make it atleast sound like its running better.

 

[Theater Effects]

Any updates on this. Having exactly same issues in a 95 GSX. Runs high idle about 3000, blows greyish black smoke, and has very loud tick from all 4 cylinders in the intake side upon acceleration.

 

[95strandedDSmR]

Fixed the problem, My timing was off 1 on the exhaust and 1 on the intake. Took it to the garage in Tarentum PA, argued with the mechanic there that did the work on my car telling him its off and showed him. He argued back telling me hes done hundreds of these cars and he knows how to do it. He then handed me a bill for 60$ without fixing anything saying the timing is fine. So I took my car to jiffy lube after hours an had me and my buddy that works there lift it up and redo the timing on the spot. Did it according to Vfaq and now the car runs, idles just fine and vacuum now reads at about 18-20 instead of the original 10-12 and other nonsense. So check you timing marks, make sure they are perfeclty parrallel to the valve cover/head surface not above, not below but perfectly even! If not, I highly recommend redoing the timing yourself and making sure its correct. And do not take it to a mechanic just because he claims hes done it for 30 years. Because now im going to take this guy to small claims for damaging the underbody of my TSI with his lift machine.