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This may be (and probably is) a dumb question, but do your wires match this picture?
Just rechecked this for the 10th time, yes they are correct. Had to pull the battery and charge it, started getting weak after all the cranking and not running. I'm really not sure what it could be at this point. Part of me wants to order new distributor caps, and rotors because the ones I put in were from a brand I never even heard of, buy new ignition coils, and stuff, and the other part of me is leaning towards the hell with it and parting everything.
Is the car a 92-95 or 96-97? On a 92-95 You injectors are going to fire in pairs (1 and 7,3 and 5). I'd be inclined to believe that it's not an ECU issue fuel wise, or you would have trouble with all 4 injectors versus just the 2. If it were a coil, you would have problems on both banks, same for ignitors, seeing how #1 and #3 are run off different coils, and ignitors. A bad cam sensor on either bank would force the motor to run on 4 cylinders, 2 on each side. You have ohm'ed those out, and they are within spec. If the wiring from the ECU was bad, It would cause the cam sensor on the bad wiring to not work, throwing the car into the aforementioned 4 cylinder run pattern.
My guess would also be injectors stuck open. The noise in the video (is not very clear) makes it seem like the engine is trying to compress something that it shouldn't be and is saved by the valves opening. The only thing that doesn't make sense in it all is the lower compression, unless the rings have carbon built up on them and aren't sealing the greatest.
Unplug those 2 injectors (after you spin it with the plugs out) and see if it sounds the same as before. If it does, grab a couple of used injectors and swap those 2 out.
Good morning bump! Does anyone know if there are differences between fuel injectors throughout the years? Might hit up the junkyard and grab a few, just want to make sure they're compatible.
I'm pretty sure I just had it running on 7 cylinders. It seems the one that compression tested the lowest is the problematic one. All I did was take out the spark plug, and unplug the injector connector and it fired up first try. It ran better then ever, so I gave it some gas and it ran pretty well. It got to the highest rpm I've seen out of it yet, but I think I gave it too much and it died. Lots of white smoke came out the rear. Do you think it's the injector? What if I pulled that injector out, and swapped it with one of the others in there? I've never messed with injectors before.
OK now I just did the paperclip trick and it's throwing only one code! CEL 13! No more 24, or 31, and the MAF is plugged in now. Previously it wouldn't start at all with the MAF in so the ECU rebuild must have done something! From what I'm seeing CEL 13 is RPM signal. This is the only info I could find on CEL 13.
So the wires are damaged somewhere, the ECU is shot, engine speed sensor is bad, the timing belt slipped or the cam sensors are bad. ECU is freshly rebuilt, cam sensors tested good on multimeter, so I'm leaning towards the others. I don't know where the engine speed sensor is, can anyone point that out for me? I also just read a thread on here where someone had two sc400's and the timing belts on both of them skipped a tooth so I'm looking into it better this time.
top dead center means you turn the crank with a 22mm socket until the crank pulley is pointing at zero.
then you pull the cam covers off and make sure the marks on the cam line up with the marks on the cover, the marks on the cam should be pointing straight up at the mark on the cover.
if it isn't pointing at the marks on the cover and is sort of pointing down instead, turn the crank one more time all the way around to 0 and check again, they should be lined up this time, if not then something is wrong.
the reason you have to turn the crank to zero twice sometimes is because a full engine cycle is 2 rotations of the crank, so it can take up to 2 turns to reach TDC, which is where crank and cams are all lined up with the marks.
so if you had the crank at zero and one of the cams pointing at the mark, and another cam slightly off its mark, then I would start wondering if the belt skipped.
I would not jump to that conclusion without checking it first cause I can tell you unless you have 300+k miles on the original belt and hydraulic tensioner toyota motors do not usually skip even a single tooth.
The tensioners are so tight you cannot compress it by hand or by leaning all your weight on it, you need a vice or a press or a very large c clamp to slowly push in the tensioner.
when and if they somehow did like if you had a tensioner failure which is rare then you would probably have thrown the belt not skipped it.
also just cause the marks are slightly off doesn't mean that it skipped, someone could have just been lazy putting it on as well.
Just checked it, and it seems the timing belt is indeed off. The left hand cam is on the mark, but the right hand cam is off by at least 7 or 8 teeth. I've done the rotation 10 times, and it's definitely off. Last time when I checked it the cam markings they were both in line, but I didn't check to see if the crank pully was at 0. So I'm going to give a few more rotations just to make sure I can get the cam's in line while it being off at the crank, and then I guess I'm ordering a new belt kit.
I smashed my hand a few times because I didn't have a big enough ratchet, what a pain in the ***. Ali thank you again for the info. For whatever reason I overlooked it. However I think getting the ECU repaired helped confirm it. If I didn't get CEL 13 I would have kept looking elsewhere, injectors, etc...
Hate to bump my thread again, but isn't it weird it's firing on 7 cylinders, but wont with 8? I'm not exactly sure how the timing belt slipping affects other parts of the car. Since I had it running on 7 cylinders is it possible I actually caused other damage to it, valves, etc...? I only had it run about 5 minutes since owning it.
The injectors are the same from 92 to 96 SC4 and 90-96 LS4.
The speed sensor is on the trans, on or near the output shaft.
Check the harness on the cam sensors too. Just because they ohm out doesnt rule out a harness side problem.
Yeah if the timing is that far off, thats more than likely the main issue. Its a non interference motor so it wont crunch the valves being off. I would still grab a few spare injectors just in case.
I had a code 13, my passenger side cam sensor was bad. Car ran pretty good. When I fixed the cam sensor it woke that mfer up.
it can be causing it to miss spark and collect fuel in that cylinder maybe, its hard to say they do wierd things when the belt is off like that. definately confirm that is your issue, and it seems like it would be.
code 13 is a cam or crank sensor code normally, I would think if your right cam is off then that cam sensor is giving a wrong indication of top dead center to the ecu, which throws off all 8 cylinders because the cam trigger is actually the start of the cycle. so its either giving you that code cause the belt is off, or there is a seperate problem with the cam sensor or wiring. sometimes the accessory belt can eat into the cam wires if they are left dangling, check that the cam wires are not shorting to the ground sheathing they are normally in (being shielded wires they are in factory shielding). thats about it for the common stuff.
my 2uz chewed through my crank sensor wire the other day after I did the timing belt on it, forgot the crank wire goes partly behind the fan bracket and if you route it in front it has just enough slack to be ripped apart by the accessory belt. lucky I am good at wiring and repaired and routed it correctly, but it was a pain.
No signs of wear to the wires for cam sensors. Even though they are very close to becoming chewed up.
Just spun the crank around a few more times to confirm, I counted 5 teeth before the right hand cam came into alignment. Belt does look to be fraying as well so I'm not surprised. I know I have a coolant leak from the thermostat housing, I'm wondering if that caused the slippage, or something else. What else would leak into the belt area? Oil if the valve gaskets bad?
would be hard to say if its fraying could be from them not knowing how to install a new one, but more likely its an old belt. I guess someone could line it up thinking its right but have left the slack on the wrong side, so when isntalling the tensinoer it would move it around or something like that.. hard to say what some people can find creative new ways to mess up a simple job.
maybe some leak on it caused it to move around, could be in conjunction with a weak/old tensioner. I do find it odd that one cam is lined up and one isn't, cause if the belt slipped I would think both would be out but I am no expert on slipping timing belts, usually mine stay where I leave them.
how many miles does your car have on it again? and how many since the last known service or you don't know?
I have once seen a case where the actual cam separated from the cam gear so the gear would spin but rest of the cam inside the valvecover would not. I dont think that happened to you though because you are still getting some compression readings.
oil from the valvecover gaskets tend to go down the side and back of the motor cause of the V- shape, but it could happen. I would probably suspect the coolant more though, do you see any patterns on the belt that look oily or wet?
I would say you need to look into a full timing belt / water pump job with a new hydraulic tensioner and bearings and check all the other little things while in there. get the motor timed up first and then go from there.
one would be tempted to just turn back the original belt but if its slipped once then I would get it out of there its probably taken damage you can't fully see yet and if they didnt do that they didn't do the waterpump and when that goes (usually locks up) it will throw the timing belt off regardless if the belt is old or new.
also to note that while most say the 1uz is non interference, they are referring to the early 1uz. around 1996 they became inteference motors and I had to look in your profile to see what year yours is, since its a 1996 you could have valve damage but your timing isn't that far out so maybe its possible you are ok but I would get it timed up right and do another compression check. at least one was in time so that bank wont have issues but its possible you bent a valve on the side with the lower numbers, or its just reading low cause the valves are not open and closed at the right times (out of timing on that cam). once you do the belt and check it you will know if the numbers go back up, if they don't I would start checking valves.
07-11-15, 02:52 PM
