3S-gte no power, miss fire? valve? injector? help! Options

[95st-celica]

Alright...as some of you know that read through my progress thread, my car caught on fire about a month ago. I replaced a lot of vac lines, some that didnt even need it but to have peace of mind i did so anyway. Everything checked out and the car ran perfect. A few days ago i put on my intake air filter and i gave her a good cleaning under the bay. i sprayed degreaser on it, scrubbed it down, and then hosed it off. about an hour later me and art decided to go out for a cruise, and it was breaking up at lower RPM's...nothing unusual becuase i use to do this with my 7A and after a while it would blow the rest of water out and it would run fine after a mile or so. I drove a good 2 miles and the car was running perfect, ran perfect all day, didnt have one problem.Later that night i took it back out, and as i was making a right, going about 5 mph i hit the gas and it lost alot of power...it was still hitting boost, but only about 8 psi, and i wasnt about to start beating on it to break something else. i pulled into a parking lot, check all my vac lines and couplers everything checked out. i pulled all plugs and they were all fine, no oil, perfect color, and didnt reak of gas. i pulled all the wires and started it up. the only one that didnt make a difference was cyc. # 4. so i knew that was where my problem was. Now i have people telling me it could be a bunch of different problems. i ran a compression test on it and it came back 140 140 135 95. i dumped 2 cap fulls of oil in the 4th cyclender and it bumped the compression up to 220. I also grabbed a stethascope and i put it on all 4 injectors to see if i could hear them ticking, which i could, except for the 4th one. what I Think the problem is, is that when i had the fire, it melted the plastic around the wires, just enough, and when they warmed up from driving the car the wires are touching and it is grounding out somewhere, causing the injector not to fire.

Possiable causese that i came up with and other people that i am trying to rule out

1) bent or chiped valve
2) cracked ringland, f-ed up piston somehow
3) ECU isnt sending a signal to the 4th injector
4) wires are melted somewhere and it is grounding out, causing the injector not to fire
5) Injector is just bad and needs to be replaced

Tomorrow i am going to rip the whole top part of the motor off so i can get to the harness. Im going to take a multi-meter and see if i have power all the way through the harness up to the injector, if that checks out then i am going to swap injectors and see if thats the caus. re-tape all my wires up and make sure nothing else is burnt, singed, ect. I am just trying to figure out where the hell and what the hell the problem is and where it is. I want this thing running and driving again, but before i do anyting i want to rule out other possiabilities. Anyone ever experience anything like this? anyones oppinions would be greatly appreciated or ideas as to what it could be. the reason im thinking it would not be a ring is because im not blowing oil out of the exhaust, and i was driving at 5mph when the loss of power happened. its not like i was beathing the hell out of it and something when BOOM, CRACK or any of that nonsense. please help, oppinions, ideas, anything is appreciated. i need my 3S back ASAP. Thanks guys

This post has been edited by 95st-celica: Jul 10, 2009 - 5:38 PM

[Fastbird]

Did you pull the cap off and make sure there was no moisture in there??? Would make sense given you degreased and hosed off the motor and the problem showed up immediately after.

This post has been edited by Fastbird: Jul 10, 2009 - 6:02 PM

[lagos]

id say look at the wiring and everything IF your compression was good, but you have almost a 50psi difference in the 4th cylinder. unless there was an error in the test or the gauge, that really does sound like your problem. i will say that it is odd that the highest number you got in the test was 140, because technically that is a bit too low, so its possible maybe the gauge is bad...who knows. i do a comp test once a year in the spring. normally i see around 190psi in each cylinder.

power comes to the injectors trough the resistor pack, and runs along the wiring that sits between the fuel rail and intake manifold. the only wiring in the back of the motor that is injector related is that intake manifold ground, but if that was bad, your car wouldnt run at all.

This post has been edited by lagos: Jul 10, 2009 - 11:42 PM