Cylinder won't fire

Tiny
MARK.PEDERSON
  • MEMBER
  • 1993 TOYOTA 4RUNNER
  • 180,000 MILES
#4, 5, and 6 cylinders are not working.
Compression - same as the workling cylinders.
Ignition - new plugs, ohm tested wires, cap, pu coils
spark is evident when I pulled the wire to find out which cylinders are not working
checked ignition timing
Fuel - raw fuel coming out tail pipe, spark plugs are wet.
tested injectors not leaking under pressure constant stream when open.
Cam timing - checked and rechecked.
Vacuum - hose routing checked (3 times)
ECU - voltage and resistance checks all with in limits
Wednesday, November 30th, 2011 AT 11:09 PM

13 Replies

Tiny
RASMATAZ
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If spark and fuel pressure is correct and injectors are pulsing-check the valve and ignition timing
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Wednesday, November 30th, 2011 AT 11:53 PM
Tiny
MARK.PEDERSON
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Checked cam and Ignition timing. How would you check for the injectors pulsing on an engine that won't idle.
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Thursday, December 1st, 2011 AT 12:05 AM
Tiny
RASMATAZ
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Disable the ignition system and crank engine over and have helper listen to injectors if its clicking-this is no a fire answer

Won't idle clean the idle air control and EGR valve and see what happens
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Thursday, December 1st, 2011 AT 12:15 AM
Tiny
MARK.PEDERSON
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EGR valve working fine. Injectors pulsing (maybe too much). Still not able to figure out why cylinders 4, 5 and 6 are not firing. Ignition timing is is showing about 40 degrees advanced. I'm getting the best results at this point.

Here's what I am seeing:
When first starting cold (about 30 degrees)the engine starts normal and runs for about 1.5 seconds. Then starts to miss and run rough. It get worse until it finally dies. When running I see white smoke from the tail pipe (raw fuel not water, there's no water in the engine). I also find fuel in the plenum and throttle body after it dies. Could it be it's flooded?

Disconnected the cold start injector, no change.
Disconnected the exhaust pipe (plugged cat?), No change.
Replaced the ECU from a known running engine, no change.

I'm running out of things to test (see the original question for the other things I've tested).

Anybody with a new idea?
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Sunday, December 4th, 2011 AT 1:12 AM
Tiny
RASMATAZ
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What testing method did you use to come about that these cylinders are not firing-Could be a compression and injector problems on them-
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Sunday, December 4th, 2011 AT 1:27 AM
Tiny
MARK.PEDERSON
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  • 7 POSTS
Pulled the plug wire with it 'running'. Used a compression tester and compared results with the working cylinders.
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Sunday, December 4th, 2011 AT 1:32 AM
Tiny
RASMATAZ
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Your ignition system is a distributor driven-not a DIS/COP configuration-How about the injectors-if okay-time to check the valve timing
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Sunday, December 4th, 2011 AT 3:37 AM
Tiny
MARK.PEDERSON
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  • 7 POSTS
I've checked the valve timing, the injectors are pulsing and as far as the ignition having a distributor, where do you think I was pulling the plug wire from? And what difference does it make? If you remove the spark from a spark plug and the engine doesn't run any different then that cylinder is not working.
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Sunday, December 4th, 2011 AT 4:37 AM
Tiny
RASMATAZ
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DIS has a sparkplug wires-People that comes here for help they say they check this and check that and everything is fine and dandy and also trying to us teach something that we have already know for such a very long time-its a no good idea.I ask a lot of questions to be sure before I give my final answer. Hint: I'm the Toy Dog here

Now you trying to teach me how to do a cylinder balance test w/o a machine-You have 3 dead cylinders here what would caused it, is compression, fuel and spark problem-Good Luck and Merry Christmas
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Sunday, December 4th, 2011 AT 5:11 AM
Tiny
MARK.PEDERSON
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  • 7 POSTS
If your reference to the "Toy Dog" means that I kicked you, sorry that was not my intent. I guess some of my frustration was showing. I apologize for being terse, and sarcastic.

Back to the problem.

Compression - I used a compression gauge. The type with the hose you screw into the spark plug hole. Turn the engine over a few times, using the starter, and read the pressure off the gauge. I checked #4 and #2 (4 is not working 2 is working) the pressures where about the same (within 5 pounds).

Fuel - Bench checked the injectors using another fuel pump in a bucket of gas and a 12V source. They did not leak under pressure and had a steady stream when on. The fuel pressure is within limits (according to the pressure gauge I had connected to the fuel rail). The injectors I assume are pulsing because the test light I probed the connector with was flickering and I have fuel coming out the tail pipe and pooling in the plenum and throttle body. I assume you mean air as part of the fuel and not just the gasoline vapors. I looked in the plenum and probed the intake manifold on those three 'bad' cylinders. I did not find a restriction. I disconnected the exhaust pipe at the manifold to test for a restricted air flow. No change in the way the engine behaved.

Spark - I can see spark jumping from the distributor cap to the wire (and my hand) on the #6 cylinder. I checked the resistance on the wires using an ohm meter. I also checked the PU coils resistance and output (by using the AC setting on the multimeter) they are within limits and about the same.

Timing - Cam timing is not 'perfect'. The indicated tooth on the cam pulley does not exactly align with the timing mark but it is the closest tooth to the timing mark when the crank is at TDC. Ignition timing is way off. The engine 'runs' best when the ignition is about 40 degrees advanced. The inductive timing light connected to #1 cylinder plug wire flashes when the crank timing mark is just about straight up, not by the marking on the cover. Hmm This is the only thing I know of that is out of limits, but when I retard the timing closer to the correct setting the engine gets worse.

I think this might indicate a problem with the cam timing. The timing belt I have has no markings on it and I could not follow the Alldata procedures for setting the cam timing using the belt markings. Maybe... But then why only 3 of the cylinders and not all on the same bank.

Thanks for helping me by letting me use you as a sounding board.
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Sunday, December 4th, 2011 AT 10:05 PM
Tiny
RASMATAZ
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Getting your frustration involved in here -will not get you anywhere

Let me ask you this: Are you jumpering the check connector terminal Te-1 to E-1 while checking the ignition timing-If not you're doing it wrong-end of my reponse to this thread, await for someone to come and assist
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Sunday, December 4th, 2011 AT 10:43 PM
Tiny
MARK.PEDERSON
  • MEMBER
  • 7 POSTS
Found the problem!
The crankshaft pulley was not properly installed. I was using the marks on the pulley to set the cam timing. Once I pulled the lower cover I could see the notch in the lower belt 'gear'. Once I reset the cams using that mark the engine is now running.
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Sunday, December 4th, 2011 AT 10:57 PM
Tiny
RASMATAZ
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You should have caught that on my 1st response
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Sunday, December 4th, 2011 AT 11:12 PM

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