SupraDremr

iTrader: (5)

No solution as of yet...Sorry just havent had any energy to research the problem for the past few weeks. One funny thing I noticed is the car runs like a dream when the a/c is on...Which raises the rpms just a little. So I tried tightening the throttle cable a bit to force the idle a few hundred rpms higher and it evened out the idle., However when I went to test drive the car it was jerking hard everytime I shifted a gear and the idle started acting up.... I set the throttle cable back to where it was and the car idles fine when the a/c is on and I would say about half the time even when the a/c isn't on, but everytime it runs good for a few stop lights and starts and stops and I think it may be fixed, the next light the idle drops to 800 then 700 about a half second later then 600 a half second later and so on until it is at about 300-400 rpm and then it starts to do the wom wom wom wom wom wom sound and you can feel the wom wom making the car move... Have not checked the iacv asit is a pain in the *** to remove the lower screw that holds it in. Did not check compression no, I do not have a tester, I will look into trying to access the iacv to test it and also the tps. What should I look for on the plugs? Just fouling? Or coloring? Sorry if that is a stupid question I know I am contemplating erasing it but I am gonna leave it. lol Anyway to test the injectors? Are you suggesting I pull the plug wires and check the plugs to see what cylinder is missing or the injector wires? Thanks for keeping this thread alive guys... Even when I was on the brink of just giving up and just driving it how it is.

ScDre

I feel what you are going through, i changed my spark plugs/wires/distributor caps & rotors and put it all back together 3 months ago, and soon after my car did what yours is doing now. So through trial and error of unhooking and reassemble( i did it so many times that i can change sparks and etc under 45 mins >_>). A mechanic friend gave me set of tongs or w/e they are sorry, that when i had the car running at same time i pulled each wire from cap with the said tool, but a word of warning they have to have a rubber grip so you wont get shocked like hell lol. Come to find out, their was one wire that was damage and had little slit in it. So i went and got my old wire that i have taken off, and put in place with damage one, and ever since then it was working good. I want to do lower mods and such for my 94 sc400 but these little gremlins keep coming out of nowhere. I cant even tell you how much money i put in just trying to get it to run perfect.

beenlookin

Bringing this back in hopes that someone has experienced the same thing and has an answer.

On another note, my friend that has been helping me had a customer come in with an SC3 that had been sitting for years. Hesitation issues and white smoke. after 3 weeks of diagnosis it came out to be a bad ecu and a bad injector.

Not the exact issues but something to also look into.

Toyboxx

iTrader: (1)

I had the same problem in my '93 SC300.

Here's the part number that fixed it. #JZZ31-1JZGTE, and that worked wonders for me!

HAHA jk. I did have the same problem, I would suggest pulling off each cap on the spark plug one at a time and see if that changes anything. Also do the same with your injectors. Sounds like something isn't firing correctly. BTW I never truly figured out the issue, as I had the 1JZ lying around, so I swapped it instead of building it like my original intentions.

HOWEVER, when I did pull the 2JZ out. I was taking off the head, and I noticed there was a crack in the headgasket by one of the water passages in the the block, so I'm not sure if that's overall what caused it or what. I never really did figure it out.

Good luck to you!

spitfire7

I changed the o2 sensors. then my car stopped bucking and dyeing.
I sprayed the maf sensor with maf cleaner.
I found a lot of vacuum leaks.
I took the iacv off, it had a little gunk/soft black dust. wiped it off then my idle got better. I got a slight power gain too. Be careful removing the that lower screw. I dropped it. It fell in between the exhaust manifold and the head. I got lucky. it fell all the way to the floor.
Hope that helps.

m1k3yg

I had some similar problems a couple months ago after I changed my headgasket (ebay ge headgasket with arp studs btw im only a broke and mechanically inclined 19 yr old) and I guess I didn't do something right because the car was running horribly, first thing was that I didn't retighten the fuel line, after that the car was running like a retarded horse, turns out my spark plugs were sunk in antifreeze (had to pull the head again because I'm still getting antifreeze in plugs) and I was having the same cold start issue you had, but mine was due to a broken connector, so I replaced both temp sensor and temp switch together with their connectors, and that had the engine running properly aside from other issues, i'd look into igniter or possibly injectors