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Less than a month ago seemingly out of nowhere the car just died after backing out of my driveway. The car can run in reverse (if it starts) but it cannot run in first gear. It idles fine but as soon as the cluth is out the car dies. Also the car does smoke white upon starting the car but it does not spew out. After inspecting the spark plugs the car does not seem to running lean at all. I then resumed to o a compression test on the car the numbers where as follow;
1. 125+
2. 145
3. 125+
4. 100
5. 130
6. 150

After reading a couple of things on supra forum i have found a couple tips for raising it (i.e. oil on each piston). And to my knowledge it suppsed to be over 160 each. I also tested it with a push down compression tester not a screw in so its not completely accurate. However based off of the numbers, #4 piston seems shot. Any suggestions on what to do? to many things it could be and its driving me crazy. ready to drive the 1j again. F*&^

Thanks,
Jeremiah

Kruso

#4 is on the weaker end of the scale and not shot. I've driven my car with just a little under a hundred under one cylinder without any major issues. On a brand new engine rebuild that I've done I only got 185 compression all around to give you a better idea. 160 is damn near excellent.

Kruso

DKNY0331

Well lower then other cylinder compressions may be the result of a burnt valve, or vavle seat, worn piston rings or a cracked head gasket... You did say you saw white smoke on start up.. if it was cold youll see the white smoke but if its warm and its a thick white maybe with a sweet smell, thats would indicate you have a blow head gastket and your burning anitifreeze...Most manufactures specify a maximum diffrence of 20% between the highest reading and the lowest reading. example if the highest reading you get is 150 multiply 20% =30. 150-30 =120. 120psi is the lowest allowable compression.... btw before i forget since the numbers all look preety dam low.. i know alot of people forget this but, Did you disable the ignition system or atleast pull the efi relay for the fuel. and then did you block the throttle plate wide open or have someone step on the gas pedal to the max while performing a compression test. all the spark plugs should be out of the engine and have the battery charging while doing this. and crank the engine over unrtill you see the needle bounce up 4 puffs and then read your guages.. Im just making sure your doing this right.. cuz those numbers look really low... ..... you could check to see if you have a sticking valve by doign a old fashion "paper test" where you have the car running and and you hold a peice of paper behind the muffler and see if the paper is constantly flying away from the exhaust... if it gets sucked in it means you have a sticking exhaust valve, burnt valve or you have a small leak in the exhaust system which would give you false reading of a sticking valve... are you confused at this point or did you get all that?

DKNY0331

also it may or may not help but... try a can of engine restorer addative, or Myster Marvel... I know alot of old timers swear that it can help fix the sticking or burnt vavle... its worth a shot its beenn around since 1918 and is only like $7 at advance auto.. and the 6cylinder engine restorer helped seat my vavle stem seals. because on cold start my engine would burn a small amount of oil since you could see it come out the tail pipe for 5 secs and then stop but i added it and the next day and since then no more smoke.. good stuff

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Thanks for all of the tips for starters. I did the test right with all of the spark plugs out and injectors unpluged(5th one is a *****) while turning the car over at full throttle. After the test i dropped in a capful of oil in each cylinder and hand cranked the motor a few rotations. After doing so and reatching it all the car started smoked alot (of course oil) but stopped after a few minutes. The car then would drive in first gear suprising and didnt die. I know this didnt fix it for sure and i am not going to take the risk of driving it on the street yet but its a start. When the gas is pressed it the smoke does come out. hopefully the head gasket but the numbers are kind of convincing otherwise.

I bought a Map ECU for starters and will definitly pick up a bottle of the resealer. Also will probably replace the head gasket and hope for the best. Hopefully I will not have to do a motor rebuild because i cant just throw all of my money at the car but I may have to.

Keep the tips coming THANKS

Jeremiah

Kruso

Dont just replace the gasket, have the head checked out by a machine shop. It only costs a few bucks and they can tell you if there's any damage to the head. At the lead get the head resurfaced to keep a head gasket from going out in the future if that is what turns out to be your problem.

Kruso

94SC3005Sp

well i am just goig to have to take it apart then huhh.. its always good to have an idea of what you are looking for though. makes it alot easier to narrow it down.

maybe its an injector anyone have any problems with them geting stuck open or closed?

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Here is the update after replacing the spark plugs and O2 sensor the car would drive and does not drop in rpms. The car does smoke a little still but only over 50%+ throttle. So the headgasket is probably about to go because of the repeated boost spikes. Other than replacing it and taking it easy till i go single not much i can do huh.

oh well. So while the heads off probably going to buy cams too and replace the headgasket at the same time.

Thanks for all of you guys input it helped alot.

Jeremiah