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vr4 blowing blue smoke

13K views 11 replies 9 participants last post by  TurboSinceBirth 
#1 ·
First time owner of vr4. previous turbo car was a wrx never had any issues with it, just not fast enoug for me. So here is the story and any help is greatly appreciated ( I am sure this is posted somewhere else but i am in a hurry to fix this issue cuz it is my only means of transportation and dont have time to surf through thousands of threads...no offense to anyone)

Everything I know about this cars condition when bought is according to the owner i bought it from.

It is a 92' vr4 with a 98 engine. Under the hood mod: two oil catch can, HID head light and fog light, Generic blow of valve, boost controller, I believe he removed the PC valve ( not sure). I believe he replace the catalyte converter with after market, but the rest of the exhaust is stock. He also install a S-AFC 2. According to him the car is currently running rich. Don't know if he tunned it with the S-AFC 2.

I also do not know if it is a requirement to change to a 98 ECU and if it is required dont think the owner did it.

When I checked out the car first time, he turned the car on and pulled out of the garage and let it sit while me and my bro checked it out. No blue smoke, nothing, so on to test drive, pulls hard and pulls quick ( especially with the three of us in it and we aint thin). Bought the car two days later for 8g's

Drove it to work right away. I tried to punch it for full boost. Third gear full boost (12 psi) cuz its a 98 motor vs a 92 (9 psi i believe) All of a sudden the car hesitates/jerks/stutter/shuts off/fuel cut/miss fires, whatever it was it stop the car from going faster, but I did not loose any boost. He installed a digital boost and it read 12 constantly. Couple days later I start to see blue smoke, not alot. Only a little when idle. But when I push the throttle blue smoke comes out. Again not alot but noticable. Then it seems to go away when I am driving. Hard to notice but i constantly look back while driving low and high speed and no smoke. Now I still drive the car but shift before boost comes on to avoid major damage, but I'm afraid damage has already been done. Sometimes i see the light blue smoke sometimes I don't. The car still spool fast and boost kicks in hard. hit full boost around 4500 rpm but car hesitates, etc...Tried to get diagnostic done a tires plus cuz its cheaper than the mitsubishi dealer (90 vs 120 bucks) but they wont do it cuz the engine has been modified. I am just trying to get it to factory tune or just make it run right.

They did recomend a tunner shop where a guy at tires plus had his rx7 twin turbo tunned, called them and they are booked 4 weeks out. told them my cars issue and the mechanic says it's the turbo field something like that. I was afraid it was a blown piston or piston ring, they say its not. The guys at tires plus say it cant be an oil leak either.

As of right now the car is still driven every day but under no boost. Still light blue smoke. still hesitate because I dont want to do more damage by testing.
When I start the car the air fuel ratio reads from 18.0 to 19.0 for about two seconds and comes down to about 11.2-13.5 When driving normal no boost going 60 to 70 mph air fuel reads 10.1. and varies to 11.5 What I have not check is what the air fuel reads at full boost cuz if it went from rich to lean I might have fried my piston and rings( god I pray with everything that it aint this)

I read all kinds of threads and talk to all the people I know who knows anything about cars and here is what I got so far:

1) blown turbo or bad turbo, symptom: blow blue smoke, lose of boost (according to the owner both turbo are working condition and even gave me the extra one that was working from the old engine, the other one was no good. so i got a turbo sitting in my garage for back up.)
2)Sparkplugs and wires need to be change since the car has been running rich. (according to the owner they have just been change, including oil, etc.)
3)blown pistons and piston rings and oil is leaking into the combustion chamber ( I seriously hope it aint this)
4)switch to 98 ECU.

I hope it is just the turbos. If it is, i'll solve it with an upgrade kit. Any help guys. love this car and wanna restore it to its full form. trying to pin point the problem so I wont waste so much time and money.
 
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#2 ·
i feel your pain man i got a black 94 3000gt beautiful as hell but my blows out alot of blue smoke and i cant figure out what it is ?? they say i need to rebuild my engine or check my wires but i hope it aint the pistons :/ but if you find anything out let me know cause i love my car
 
#3 ·
10.1 to 11.5 AFR at cruise is extremely rich. if goes any higher than that under any throttle then that is prob what the hesitation comes from. a buddy of mine over here has his cruising at 16 afr on an AEM. so you can see the difference. little bit of blue smoke isnt too much to worry about. it is most likely a turbo on its way out. easiest way to tell is to pull the intercooler pipes off the turbo and check to see if there is oil pooled in the compressor. and check for shaft play.

im assuming these are factory 9b turboes right? what injectors are on there? what are the SAFC settings at? is the fuel pump hotwired? post this stuff up and we can go from here
 
#7 ·
So you running stock turbos?
Four major causes of oil smoke

1)engine mechanical-bad piston oil rings,scorched cylinder walls,worn pistons...anything that will allow oil into combustion chamber from crank case.Oil smoke blows pretty much constantly: on idle,acceleration,deceleration depending on how much the damage is.
Compression test may not revile this condition since compression rings probably ok. proper test is engine tear down.

2)bad valve stem seals,mostly occurs at idle,usually goes away after driving a while,if damage is moderate will not appear at acceleration or deccel.If not to bad could be rectified with oil 15W50 or such.Also a good test to verify bad VSS

3)bad turbos:turbo seals leaking oil ether from turbine side-(exhaust side) into hot exhaust pipes or compressor(intake side) and pushed under boost and/or sucked under vacuum into intake manifold. Exhaust side leak appears mostly on acceleration,intake side leak mostly on deceleration.Remove exhaust to inspect for oil leak from turbo if not present,remove intake pipes-inspect for moderate oil inside and at throttle body.

4)Bad PCV system: sucking oil into intake due to bad PCV valve or from rear valve cover into intake pipe.Occurs mostly on deceleration,really easy to check and fix,replace PCV valve and temporarily unplug and cap(to prevent vacuum/boost leak)rear valve cover to intake pipe hose

Other possibilities, clogged oil return lines,to much blow by-pushing oil back into turbos from crank case and so on...
Numbers 2,3 and 4 most common culprits and easy to check and fix,so I suggest start with that.
As far as you running issues you must start with basics, check compression,plugs,plug gap, ignition wires,coils,vacuum or boost leaks...SAFC settings corresponding to boost numbers....
 
#11 ·
BTW...92 VR-4 with 4 bolt stage 2 bottom end. heads rebuilt. dr650 turbos. about 1000mi on everything.

Also, there is a significant amount of oil in the front 3 cylinders. All 3 plugs are black and soaked in oil. Haven't checked the rear bank yet.
 
#12 ·
What brand is the PCV valve? OEM is the only one that blows the right direction. The parts store ones are wrong. I'd check the turbo compressor cover outlets for oil to see if it's coming from the turbos. Are they billet or rebuilt cast DR-650s?
 
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