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My 3SGTE has a dead third cylinder. Firstly we checked compression and it was good, even across the board. Secondly we checked ignition components, by swapping wire, plug with friends car. Even hooked up a timing light to the ignition wire to make sure it was pulsing. Ignition components are fine. We decided it was a fuel problem and I had a set of injectors balanced and cleaned and threw them in, no change. We hooked up to the fuel injector power/ground wire and it is recieving power. Pulled out the EGR valve, and it seems fine, no apparent problems. HELP!!! We are thinking some sort of vacuum leak perhaps around the 3rd injector, or under the rail that the injectors sit on. We sprayed intake cleaner over the area as the car was running and the idle would increase abit when we hit certain spots. What could it be? The other cylinders are fine, the car passes emmissions on the driving test, but fails the idle test due to too many hydrocarbons. Thanks for any help.


Update: Have changed all seals around Fuel injectors and rail, have taken off valve cover and cams apear fine.

Still no solution, could it be the intake manifold gasket? It seems I have a vacuum leak somewhere as the car is more frequently struggling to raise the idle while the Vac gauge shows 16-18hg when this happens. Also when we spray intake cleaner in the area, the revs seem to raise for a sec and then drop again. Any other opinions would be greatly appreciated.
 

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i think i remember this from a previus thread.. remember that you have a tvis system-- this means that you have more places that can be leaking..there are 2 intake gaskets plus the spacer with the tvis system in it.. make sure the nuts are tight-in spec.. they are maor accesable from the bottom..
the gaskets are high quality toyota parts--metal covered with some type of non stick coating.. it is unlikely that they blew out, but they can leak if the intake is loose..
the cams looked fine, did any of the lobes look rounded?
you mentioned to many hydrocarbons-- isnt that to much raw fuel in the exhaust?. is it possible that the plug isnt firring all the time? ive had plugs ffoul and the spark would jump way down the porcelein across to the metal..
you had orriginaly done a cyl balance test, right.. remove one wire at a time and note the change..when you do this test again, do you get the exact same result?
 

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Demon,

I now am beginning to remember this one. I believe, as chrisman suggested repeating, he was pulling plug wires and noticed no difference for #3. I think it was just an idling situation.
 

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you need a leakdown test then. there may be a pit in the cylinder wall toward the bottom of the piston's stroke, so it still has enough stroke to still build up compression. however if that were the case, it would be smoking like a mofo. but still.. leakdown test :)
 

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[why exactly do you think you have a dead 3rd cyl?] -Demon

I'm thinking the same thing. It sounds like you have compression, spark and fuel on all cylinders.
If your idle is irratic it definitely could be a vaccum leak, but in that case you've got to check the whole system starting at the AFM and going to where the intake manifold reaches the head. Start with anything you may have touched or changed about the time the idle began getting funky. There are a number of hoses around the intake manifold area that are more easily seen from underneath the car, the turbo VSV, and TVIS actuator and vaccum tank. Others I can think of are, fuel pressure regulator,Idle bypass, PCV, turbo actuator, EGR, charcoal canister, turbo pressure sensor. There is also at least one cap on an unused intake manifold port. Make sure all these are attached and the hoses are not cracked or leaking. That fact that the car idles and doesn't die suggests that it is a small leak. A big leak would prevent the engine from idling. Turbo engines are always trickier because vaccum lines have to be able to stay in place under boost as well as vaccum. you might start adding or replacing clamps on some hoses as you go so that you know they are not causing problems.
One other long shot... there are small round seals around the TVIS shaft. If one or both of those were damaged they may be letting in a bit of air and intake cleaner when you spray. Doubtful but I guess anything is possible. Try to tighten your manifold bolts a little to make sure they are not loose. Spraying intake cleaner down there shouldn't have an effect on the idle if the system were sealed like it should be so you're probably close. Hopefully you've tackled it already.
Good luck, vaccum leaks are a pain to locate as I'm sure you already know.

Later,
Chuck
 

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A compression test wont tell you if your hg is blown.

A quick test is to start the car and pull one spark plug wire at a time and see how much of a difference it changes the idle. If it is a large cahnge then that cylinder is strong. If there is no change that cylinder has leaking problems. I believe that is what he was talking about.
 
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Thanks for the responses guys.

The reason my 3rd cylinder is dead is because when I pull wires from each cylinder while the car is running, the 3rd wire does not do anything to the engine while pulling any other wire bogs the car right down.

I am pretty sure it is a vac leak myself, however I was wondering what kind of leak and where/which seal would affect only the 3rd cylinder to the point it does not combust at idle (hence the hydrocarbons) speed, yet the other three cylinders run.
I am going to try and tighten the bolts around the intake manifold and see what happens. Could a leaking T-Vis system be affecting the 3rd cylinder alone?
Also want to add that the car does not smoke at all, cam lobes were not rounded.
Appreciate the suggestions!
 
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1950844_ I thought a compression test would show a leaking HG? Also the car does not smoke.. It does drink about 2 quarts of oil between oil changes though.
 

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I think you have two choices. You can identify the leak by removing the intake cam and pressurizing the intake. Or, you can take it apart to look for the leak. I always want to identify what is wrong before I start pulling it apart looking.
 

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why remove the intake cams? why not just open the intake valves during a leakdown?
a vac. leak will affect all cylinders not just one. although fluctuating 16-18"hg is not at all good.
make sure youre using a tach. (digital if you have a dmm) when youre doing your cylinder balance test and compare how much rpm drop per cylinder disabled. whether your disabling fuel(disconnecting injector harness) or pulling a plug wire(you have to ground it unless you just dont like your module/igniter).
 

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These problems don't point to a vac leak. I suspect that your either have a 1) bad inj3 driver in your ECU, 2) bad #3 injector, 3) problem in your engine harness with the wires going to the #3 injector or 4) a fuel injector resistor pack with a blown #3 resistor. Use an ohmmeter to test the packas per the BGB. If that ohms out, ohm out the wires from the pack to the #3 injector connector. If that's good, borrow another ECU and try it, if that is good, then borrow another injector and try it.
 

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Thanks for the input guys......

Test specs...
Compression was even across all cylinders
Pull ignition wire from #3 and there is no change to engine RPM
Swapped spark plug into #3 hole no change
Swapped wire on #3 no change
There is good spark coming out of #3 wire, timing light confirms this
Swapped in a set of tested and balanced injectors, not change to #3
Pulled hole injector rail and replaced gaskets that seal into head.
Put a noid light onto injector #3 and there is power and ground

My problem is that why is cylinder #3 dead. Normally you won't have one dead hole from a vacuum leak. Unless the leak is between the injector and the cylinder causing the A/F to go lean.
Because if the leak is before the injector it isn't going to cause a leak condition on that hole.

The car's rpm does pick up and engine smooths out when you spray Air Intake cleaner down towards the intake manifold gasket. This is why I think its a vacuum leak....
But a bad injector driver in the ecu does seem possible as well

thanks
Cam
 

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RickyB's systematic procedure would indeed be the easiest approach. I would not want to go to the trouble I outlined before I used his plan.
 

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posted by RickyB
These problems don't point to a vac leak. I suspect that your either have a 1) bad inj3 driver in your ECU, 2) bad #3 injector, 3) problem in your engine harness with the wires going to the #3 injector or 4) a fuel injector resistor pack with a blown #3 resistor. Use an ohmmeter to test the packas per the BGB. If that ohms out, ohm out the wires from the pack to the #3 injector connector. If that's good, borrow another ECU and try it, if that is good, then borrow another injector and try it.
Why spraying air intake cleaner around the intake manifold does cylinder #3 come back to life ?
 

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My 3SGTE has a dead third cylinder. Firstly we checked compression and it was good, even across the board. Secondly we checked ignition components, by swapping wire, plug with friends car. Even hooked up a timing light to the ignition wire to make sure it was pulsing. Ignition components are fine. We decided it was a fuel problem and I had a set of injectors balanced and cleaned and threw them in, no change. We hooked up to the fuel injector power/ground wire and it is recieving power. Pulled out the EGR valve, and it seems fine, no apparent problems. HELP!!! We are thinking some sort of vacuum leak perhaps around the 3rd injector, or under the rail that the injectors sit on. We sprayed intake cleaner over the area as the car was running and the idle would increase abit when we hit certain spots. What could it be? The other cylinders are fine, the car passes emmissions on the driving test, but fails the idle test due to too many hydrocarbons. Thanks for any help.


Update: Have changed all seals around Fuel injectors and rail, have taken off valve cover and cams apear fine.

Still no solution, could it be the intake manifold gasket? It seems I have a vacuum leak somewhere as the car is more frequently struggling to raise the idle while the Vac gauge shows 16-18hg when this happens. Also when we spray intake cleaner in the area, the revs seem to raise for a sec and then drop again. Any other opinions would be greatly appreciated.
Did you ever figure out the problem?
 
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