trouble in the bay!!

[sunnyd5118]

Engine bay that is.... hahaha
Hey all, I am perplexed as to where to begin.

The Car: 1991 Toyota Supra NA. It was bought from a junkyard on pocket change and rebuilt (Another one saved from the dust!). I bought a Japanese Import Engine (bulk wholesaler) and rebuilt from the bottom up. Block and crank were honed and polished and so forth, along with complete gasket set.

The problem: The head was also taken care of, but I am not sure it was done properly. Not but 1000 miles in, I noticed a light valve tap -- it would come and go in volume, but could hear the clearest when driving (right behind the glovebox). Wierd! I am pretty sure that I can rule out the tap coming from the injectors, they are more of a click than a tap. Also as a side note, it may have a turbo oil pump in it. When all parts were recieved from toyota, I was sent a turbo gasket kit (which means a turbo oil pump could have been sent since the order was placed at the same time). It wasnt realized until after the pump was in and everything sealed up -- I guess that it might be partly to blame.

Problem 2. Could be related to previous. While idling, and if I remove the oil filler cap, the car will drop in idle and stall (unless I keep idle at the throttle body.) If I keep idle, it will equilibraite seconds later and hold idle fine with the cap off. Vacuum leak????? It was japanese engine and all emmisions parts had to be transferred.
It does one more thing related. The trip back to denver is down a interstate with 7 % grade for 4 miles. After coasting down (3000 rpm) to the bottom of the hill, the car will burn oil every time I accelerate for the next couple of miles (doesnt seem to at idle, only acceleration). At no other time does this car burn oil, except this one specific scenario. ( Could be emmisions from top of cams to throttle body- oil being suck into the intake manifold??)

One more....i promise.
It is normal for the gas to pressurize during normal driving. Mine seems to pressurize too much. sometimes I smell foul, skunky gas while driving and have pinpointed it to the line into the charcoal canister leaking. If I were to remove this line, there are fumes that pour out of it (is pretty cool to look at, but not for too long.) It is my third charcoal canister that I put on (all were used canisters) but I doubt the canister is to blame. I would just plug the line, but afraid that if it is actually building high pressure inside tank, I might blow other lines or start leak out the seals of the gas tank.

I know that this was awfully wordy, but Ive had several weeks to ponder over the situation and try and cover all aspects of the seemingly haunted car.

Thanks in advance and any input is extremely appreciated.
Good driving

[supramacist]

When you had the head done did you also get a valve job??

If not the rubbers could be worn.
Maybe..., you have piston slap in #6

I have a 91 na also. These things like oil.
Check it daily and keep some in the car.

If you don't check it daily. The minimum would be every time you fill up.

Check your air filter for petroleum based contaminates.

I have never heard of some the things you mentioned here.

All hg gasket sets come as turbo. Because the na's don't use everything in it and their are more gte's than ge's.

Sometimes you order turbo parts knowing they will work on your car.

[sunnyd5118]

Thanks for your reply...
I am not 100 percent sure what was done with the head. I know it was magnafluxed and cleaned. Im also sure that they also checked and cleaned the valves and valve seats when they had it apart, but not sure if they replaced anything or checked any clearances.
I hope that it is not piston slap, but the best way to check would prolly be a mechanics stethoscope- right? Im replacing my shocks and will try and check it out this weekend. I hadnt thought of that since I just recently put it together. Oh well, I guess these things happen.

[jfunez]

the gas tank pressurizing seems to be that you have the vent solenoids or purge valves's vaccum lines hooked up wrong or one of them simply not working....double check all your vacuum lines per TSRM vacum diagrams..

Improperly routed vacuum lines also seems to be the problem with the vehicle idleing and stalling when removing the oil filler cap...

as for the smoke or usage of oil during acceleration after a downhill is a symptom of bad valve seals.....

[f00g00]

I beleive it is normal to have some idle drop when removing the oil filter cap because you are inducing a huge vacuum leak when you do that, but the car shouldn't stall so like jfunez said, check for improperly routed vacuum lines, and check for leaks elswhere. Check the pcv system too if its clogged.
How much pressure is there when you remove your gas cap?

[west_side_supra]

i will say for the foul skunky smell could be a bad cat, does it smell like sulfur

[sunnyd5118]

Thanks to everyone for their comment and suggestions. Ive been busy trying to winterize it for a denver winter. Replacing shocks, buying dedicated snow tires, and lining hatch with, say, 300 pounds of concrete. wonder how it will do....? Im not tooo terribly confident.
I was afraid that it was simply vacuum leak. It would the the cheapest fix, but potentially the most aggravating. Ill be checking it this weekend, hopefully.
My gas tank isnt always pressurized so much that it leaks. But when it does, you can smell it in the cab and was verified by sniffing near the charcoal canister. Removing gas cap produces a second long hissing and whoosh of air. It doesnt seem like it is pressurized much more than other cars that I have driven. It is also an intermittent problem, so it makes it more difficult to diagnose.
Ill keep yall posted with what I find--- as I can find it.

[supramacist]

WOW.

The charcoal cannister is there to remove undetonated fuel.
You may need a fuel pressure regulator.
have you played with the afm at all??
I'm just going over randoms so I'll stop.