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Ask Ted Ritter Your Own Question
Ted Ritter
Ted Ritter, Toyota Master Tech
Category: Toyota
Satisfied Customers: 4400
Experience:  Toyota Master Tech, ASE Certified
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Corolla: 2004 Corolla won't fire but has spark, fuel and c

Customer Question

2004 Corolla won't fire but has spark, fuel and compression.
Submitted: 2 years ago.
Category: Toyota
Expert:  Ted Ritter replied 2 years ago.
Thanks for posting
Was it running ok before replacing the headgasket?
Have you checked for injector pulse voltage yeat?
Any diagnostic codes in the computer?
Customer: replied 2 years ago.
It quit on the road with no fuel pressure. I started with replacing the pump and now there is pressure. A 17 year old was driving it when it quit so little info. I have checked injector pulse and it is present. No codes at all. I'm an experienced mechanic but I'm missing something somewhere.
Customer: replied 2 years ago.
When it didn't start after fuel pump replacement I started checking it out and found Timing was off about 8 degrees and compression was 30psi on two cylinders. That's why I did the head gasket and timing parts.
Customer: replied 2 years ago.
The driver said he started to pass a truck and it started running rough, pulled over and cut it off. Hasn't fired since. I picked it up with a dead battery and brought it home.
Expert:  Ted Ritter replied 2 years ago.
Thanks, ***** ***** compression was low due to burned valves on two cylinders and the compression is good on all cylinders now? Can you check intake vacuum while cranking the engine? I,m curious about what kind of vacuum the engine has.
Customer: replied 2 years ago.
Head gasket was leaking, all compression is good now. Vacuum is 16 in while cranking
Customer: replied 2 years ago.
I figure some of the compression loose was due to the stretched timing chain.
Expert:  Ted Ritter replied 2 years ago.
Everything seems to be ok, the problem may be the ECM, this may be why there are no codes stored, there is a recall in effect from Toyota for defective ECMs which can cause some weird problems, check the ECM part number, it's located below the glove box, let me know what the part number is ***** I'll check to see if it applies, the first numbers are something like 06991 followed by some letter and numbers.
Customer: replied 2 years ago.
Here is s picture of the label
Customer: replied 2 years ago.
I don't understand how I can have fuel, spark and compression and it not at least try to start. If the ECM is bad wouldn't there be no spark?
Expert:  Ted Ritter replied 2 years ago.
No, it's out of the affected number range. Not really sure what's going on with this engine, if there was an input sensor malfunction there should be some code information, a fuel delivery problem won't set any codes but you say it has fuel pressure and the injectors are working and there is spark, good compression and good vacuum and the timing is ok, this engine should run. Possibly contaminated fuel, water in the tank, someone put diesel fuel in, anything like that could be the case.
Customer: replied 2 years ago.
The fuel pressure is 45 psi while cranking, the pump doesn't run until you start cranking, is that right? Haynes book says it should come on with the key in run but I read somewhere else Toyota doesn't do that.
Customer: replied 2 years ago.
Fuel is clean, I checked all that when I put the pump in.
Customer: replied 2 years ago.
I've had the injectors laying on the valve cover and they all spray fuel.
Expert:  Ted Ritter replied 2 years ago.
The computer gets a crankshaft signal from the cranks sensor which causes the pump to run, after that the circuit opening relay keeps the pump running. It does not run with just the key on.I really don't have an answer for you and I have to go offline until tomorrow, you have the choice to opt me out and wait for another expert that may have an answer for you or re list the question, please do so without rating when they ask you to do so. If I can think of something else overnight I will reply to you tomorrow.
Customer: replied 2 years ago.
Coils are 4 wire, I have battery power to #1, 5 volts on #2 with key in run, #4 has zero resistance to ground.
Expert:  Ted Ritter replied 2 years ago.
The black wire to each coil should have 12 volts with the key on, the white/black wires are the ground wires and should show zero ohms or less to ground, the other wires are spark and timing confirmation signals to the ECM.
Customer: replied 2 years ago.
Ted, I actually figured it out this morning. The exhaust cam gear had sheared the alignment pin and it was off. Amazing it still had compression but was exhausting has it should be firing.
Expert:  Ted Ritter replied 2 years ago.
Probably was over revved when it quit running and I bet it bent some valves too which you already took care of, makes sense now.
Sometimes taking a break from a problem and re thinking everything helps. Good luck, we both learned something.
Customer: replied 2 years ago.
Pictures are worth a thousand words. I didn't find any bent ones or any signs of contact. It's running good. I'm sure it was rev'd high. Thanks for talking through it with me.
Expert:  Ted Ritter replied 2 years ago.
You're welcome, best of luck, please take a moment to rate my answers