Another 88 Supra Problem

[iMod]

Well guys I got my valve cover seals fixed and it was all going very well. Now 1100 miles later, I've encountered another problem.

I went to work one night and when I finished my shift I went outside and tried starting my Supra but it didn't wanna start up. I took off the manifold and checked all the spark plugs and there is a little bit of coolant in there but I found out there was a hose dripping coolant into them. So I got them cleaned out and the coolant line clamped better. It still didn't wanna run though.

Basically when I start it up, it'll shoot up to 2000 rpm's and drop. Then back up to about 1,500 rpm's then drop lower then the first time, then it goes back up to roughly 1000 rpm's and then it'll drop to about 250 rpms or lower then it'll sputter and die.

If I rev the engine to 4000rpms as soon as I start it, then it'll stay going as long as I keep it at 4000+rpm's. I did that for about a minute then let off the gas and it ran just fine as if nothing was wrong. I took it home and started it up again about an hour later and it was fine. Then an hour after that I tried again and it did the same thing while it was running. It started sputtering and it died again. The spark plugs and all that are still clean.

Does anyone have any idea of what's going on. It's been a few days since this happened cos my computer isn't getting a wireless signal so I couldn't post it sooner. Anyways if I don't respond very quickly then that's the reason why.

Thanks

 

[supra_man87]

i had a similiar problem when i gave my car a tune up a couple of months ago. what i did to fix it was, well its kinda hard to explain, but there is a wire that pulls back on your throttle body to open it. there is a screw there, i call it the idle possition screw, you can adjust that, but remember where stock is, and if that doesn't help, there is also a bar around there that pushes the throttle body closed, you can adjust that to make it longer so it closes better at idle.

but there is another way posibly, but thats what i did and my car is running strong and flawless. hope this might help.

 

[jetjock]

:nono:

 

[bapmk3]

i had the same kinda problem with my 86.5 but mine was from ignorance. i pressure washed my engine and a lot of water went into the vally where the spark plugs are and it didnt start running badly untill i got a couple of miles away, so i went in with a rag and got enough out to start it and drive it home then i took all of the spark pluge wires out and grabbed my aircompressor and finished getting all of the water out of the valley and it ran fine after that, it was running rough because the spark plugs were shorting out in the water and missing i would take an air compressor to yours and clean all of it out if you can. If not, i wouldn't recomend this way, but you can take your spark plugs out and let the water go into the cylender but you also have to change the oil right after you do it, if you have any other option than this i would do it.

 

[Finnon]

that sounds like it could be a split hose on the crank case vent. my bros old car (ford escort) had a similar problem, revs bouncing all over the place.

OH and i would leave all the various throttle linkages set as they are. might mess up some of the settings there if you play about too much

 

[Kckazdude]

but there is another way posibly, but thats what i did and my car is running strong and flawless. hope this might help.

:runaway:

Somethings should not be tampered with when not understood.

 

[ms07s]

The hose going to the TB is probably old and cracked....it slowly drips coolant into your plug vally. Replace those and leave your Idle alone.

 

[cuel]

Messing with the throttle stop(not an idle adj. screw) is a bad idea. It's set by the manufacturer to a specific point, and is not meant to be moved.

iMod: An easy way to clean out the plug wires is wd40. Will remove all the water, and return a good contact. For the spark plug holes, compressed air works best, but you can get most of it with paper towels.

 

[iMod]

Thanks for the advice guys. I went out today and thought I'd try and see if the car would start up and it did. It went down the road a bit then started to die and so I gave it some gas and it kept running.

I started going down a hill though and the rpms started bouncing again and it died. I'm not sure what the problem is now but I'm gonna keep messing with it. Anymore suggestions would be much appreciated.

Cuel: I'll try the WD40 tip. I thought about it and it makes sense since the WD40 is a water depressant.

 

[cuel]

ROFL. Sorry, that's just funny-- depressed water.

Get a pressure tester and find the coolant leak. Check the heater hose that goes to the back of the head, coolant lines to the t.b.(as mentioned), and the 4(?) big allen bolts in the top of the spark plug galley. They block the coolant passage thru the head, and I think I remember someone having a problem with them leaking before.