My recent 86 GN project is getting a little sour...kinda goes like this
First, I will start with as much info as I can think of:
71k miles, sitting mostly for a LONG time, needs some body & trim work-but barely ran when I got it.
Was told it had a recent engine rebuild, but don't have details other than "stk rebuild". Also was told the trans was replaced and came with a shift kit & high stall converter (claims 3500-but doubting that). Does feel like it ramps pretty quick, but does not feel outrageous and drives quit nicely under normal throttle conditions, shifts firm/hard though. Stk turbo, inj, reg, 3 chips (1 stk, 2 unknown origin burns)-stk installed.
Now what I have found & done:
First, installed battery. Fixed a few vac lines. Car now idles, but not real smooth. Bad miss/bucks under load. Pulled & replaced plugs, all fair and evenly colored EXCEPT #4, slightly darker than rest, but not wet-I felt that injector may be a bit rich. Replaced rediculously mismatched wires. Checked fuel pressure, good at idle, fell off under load. Fuel filter found loaded with rusty fuel. Dropped tank & flushed it out. Installed new 340 pump w/hot wire and changed fuel filter, installed used adj reg set to 42 psi vac off. Ran good for 1 day, then same as before. Loosing fuel pressure, pulled filter, full of rust again. Replaced tank, cleaned sock and install another new fuel filter. Ran good, idle ok for the most part-lights the tires up without power braking clear to the 1-2 shift. Things seem to be going a little better at this point-BUT now noticing a little smoke at idle-intercooler piping and t/body has oil residue-some shaft play in turbo. Replaced turbo with used piece, checked oil feed line for good flow. I had been showing knock on the Tech I scan tool on the 1-2 shift. I reset the TV cable but then it would shift REAL hard 1-2 plus would hit the rev limiter unless I backed out of it on WOT. Found two clicks in seemed to make it happy, but did not get much time to play with this. Couldn't get through emissions insp, tried lowering fuel pressure but could not adjust lower (checked w/two gauges-same on both). Replaced with new Accufab, same thing-can't adjust down-same pressure with or without vac line hooked up. Yet another problem now, smoke from the tailpipes again. This time nothing in the intercooler pipes or t/body (at least not yet, lol). Found oily fluid dripping from elbow/wastegate arm area-yikes. I was thinking my used turbo was leaking on the exhaust side (and very well could be), but I was curious so I pulled that #4 plug again-its now real dark, wet and pretty obvious its oil. So I went home...disgusted.
Well, I posted this thread here mostly because I need advice about the oil in cyl #4 and if I need to pull the heads...(engine tech related) I was considering replacements. That will still leave me with the fuel pressure issue to repost elsewhere unless someone is kind enough to guide me there also.
My thoughts on the oil in cyl #4:
Bad oil ring, headgasket, valve guide or seal.
Things to do-check vacuum, check compression, pull valve cover for visual inspection. Hope I find a problem within the head.
My thoughts on the oil leaking from turbo exhaust housing:
Hope its related to the oil in #4, if not NEW turbo upgrade.
My thoughts on the fuel pressure issue. restriction in the return line, so fuel pressure is always about 42-45 lbs. Vac change or reg adj does not effect reading at idle.
Anyhow, I am about out of breath here (actually fingers are as tired as your eyes). If its not a valve seal and I have to pull the heads-I would like to keep this simple for the most part. If its a guide, I was thinking of going cheap with a used one and transfer hardware (new LT1 springs would probally be a good idea here). If I have to pull the engine, assuming the piston & cylinder wall is ok-just re-ring that cylinder.
Funds are not endless, so economy is foremost on my mind. BUT with the heads off, I was thinking of port/polishing them and the intake. Another option are a pair of fully assembled Stage 1 Jr's. $400 for a set seems cheap enough. I don't have any plans for a roll bar, so 11:50 would be the max ever to go(future turbo/inj upgrades of course) and unless something else happens I don't plan on tearing down the engine to go faster. Bolt on only.
I can't seem to find much of anything on the Stage 1 Jr's, so if someone knows about them. Please list goods and bads. Will they work with a stock cam? I know better flowing heads are more important with faster cars (bigger cams, converter, turbos, etc) and better head flow for milder applications really is a waste. But if the heads work better than stock, then they may be a good upgrade with the engine appart. Turbo upgrade will happen sooner or later. Cam is not planned unless I find it toasted after teardown (again, if it goes that far).
I am sending the car to the body shop for some work soon, so if I do have to pull the engine I will have a couple of weeks to work on it.
Thanks for listening, and for any good advice.
Nasty
Related to #4 cylinder, or leaking from exhaust side of turbo.
First, I will start with as much info as I can think of:
71k miles, sitting mostly for a LONG time, needs some body & trim work-but barely ran when I got it.
Was told it had a recent engine rebuild, but don't have details other than "stk rebuild". Also was told the trans was replaced and came with a shift kit & high stall converter (claims 3500-but doubting that). Does feel like it ramps pretty quick, but does not feel outrageous and drives quit nicely under normal throttle conditions, shifts firm/hard though. Stk turbo, inj, reg, 3 chips (1 stk, 2 unknown origin burns)-stk installed.
Now what I have found & done:
First, installed battery. Fixed a few vac lines. Car now idles, but not real smooth. Bad miss/bucks under load. Pulled & replaced plugs, all fair and evenly colored EXCEPT #4, slightly darker than rest, but not wet-I felt that injector may be a bit rich. Replaced rediculously mismatched wires. Checked fuel pressure, good at idle, fell off under load. Fuel filter found loaded with rusty fuel. Dropped tank & flushed it out. Installed new 340 pump w/hot wire and changed fuel filter, installed used adj reg set to 42 psi vac off. Ran good for 1 day, then same as before. Loosing fuel pressure, pulled filter, full of rust again. Replaced tank, cleaned sock and install another new fuel filter. Ran good, idle ok for the most part-lights the tires up without power braking clear to the 1-2 shift. Things seem to be going a little better at this point-BUT now noticing a little smoke at idle-intercooler piping and t/body has oil residue-some shaft play in turbo. Replaced turbo with used piece, checked oil feed line for good flow. I had been showing knock on the Tech I scan tool on the 1-2 shift. I reset the TV cable but then it would shift REAL hard 1-2 plus would hit the rev limiter unless I backed out of it on WOT. Found two clicks in seemed to make it happy, but did not get much time to play with this. Couldn't get through emissions insp, tried lowering fuel pressure but could not adjust lower (checked w/two gauges-same on both). Replaced with new Accufab, same thing-can't adjust down-same pressure with or without vac line hooked up. Yet another problem now, smoke from the tailpipes again. This time nothing in the intercooler pipes or t/body (at least not yet, lol). Found oily fluid dripping from elbow/wastegate arm area-yikes. I was thinking my used turbo was leaking on the exhaust side (and very well could be), but I was curious so I pulled that #4 plug again-its now real dark, wet and pretty obvious its oil. So I went home...disgusted.
Well, I posted this thread here mostly because I need advice about the oil in cyl #4 and if I need to pull the heads...(engine tech related) I was considering replacements. That will still leave me with the fuel pressure issue to repost elsewhere unless someone is kind enough to guide me there also.
My thoughts on the oil in cyl #4:
Bad oil ring, headgasket, valve guide or seal.
Things to do-check vacuum, check compression, pull valve cover for visual inspection. Hope I find a problem within the head.
My thoughts on the oil leaking from turbo exhaust housing:
Hope its related to the oil in #4, if not NEW turbo upgrade.
My thoughts on the fuel pressure issue. restriction in the return line, so fuel pressure is always about 42-45 lbs. Vac change or reg adj does not effect reading at idle.
Anyhow, I am about out of breath here (actually fingers are as tired as your eyes). If its not a valve seal and I have to pull the heads-I would like to keep this simple for the most part. If its a guide, I was thinking of going cheap with a used one and transfer hardware (new LT1 springs would probally be a good idea here). If I have to pull the engine, assuming the piston & cylinder wall is ok-just re-ring that cylinder.
Funds are not endless, so economy is foremost on my mind. BUT with the heads off, I was thinking of port/polishing them and the intake. Another option are a pair of fully assembled Stage 1 Jr's. $400 for a set seems cheap enough. I don't have any plans for a roll bar, so 11:50 would be the max ever to go(future turbo/inj upgrades of course) and unless something else happens I don't plan on tearing down the engine to go faster. Bolt on only.
I can't seem to find much of anything on the Stage 1 Jr's, so if someone knows about them. Please list goods and bads. Will they work with a stock cam? I know better flowing heads are more important with faster cars (bigger cams, converter, turbos, etc) and better head flow for milder applications really is a waste. But if the heads work better than stock, then they may be a good upgrade with the engine appart. Turbo upgrade will happen sooner or later. Cam is not planned unless I find it toasted after teardown (again, if it goes that far).
I am sending the car to the body shop for some work soon, so if I do have to pull the engine I will have a couple of weeks to work on it.
Thanks for listening, and for any good advice.
Nasty
Related to #4 cylinder, or leaking from exhaust side of turbo.
