No spark but only when hot?


#1

My 92 Toyota Celica 2.2liter is having and issue of no spark, but only when hot. When the car is cold it starts up everytime but once it is at normal operating temp it will start up a couple more times and then it isn’t getting spark. The wierd thing is when I try to start it and let off the key quickly and try to start it again it will usually start up. Once the car is running it runs fine and stays running. So far I have checked the wiring between ECU and the distributor and igniter with and OHM meter and it seems fine. I have replaced the distributor, coil, cap, rotor, plugs and wires, and igniter with new Toyota OEM ones. I tried another ECU from the junkyard, but I can’t honestly say if that one is working properly. I’m out of ideas on this when the car is running it runs great, it’s just getting it running. The cars operating temp stays right about 175 to 190, so it it not abnormally hot. Any ideas are appreciated.


#2

My guess is there is a problem with one of the engine sensors. Have you checked the ECU for any error codes when the trouble happens? A sensor could be intermittent or the connection to it may have a problem.


#3

I forgot to mention that I ran the codes and there are none. The computer reports everything is fine. Someone already said it sounds like a crank or cam sensor, but I’ve found out these are integral to the distributor, which I’ve just replaced. Thanks.


#4

When it is hot, and not starting, does the coil get 12V power? And the ignitor? Sometimes the problem is simple.


#5

Some clarification first. When referrring to spark, do you mean the starter motor will not crank the engine over or that it cranks over but does not start due to lack of spark at the spark plugs?


#6

I wonder if there is a problem with the ignition switch. When you turn the key to the start position, the only system that feeds through the ignition switch that receives power is the ignition and fuel injection. It sounds to me as if in the crank position, the ignition is not receiving power–just the starter motor. If your car is a manual transmission and this problem occurs, turn the key to the run (ignition on) and try push starting the car. If it starts, I think that the problem is most definitely the ignition switch.


#7

What I mean is the starter cranks, but there is no ignition spark. I do know when it won’t start, but the key is in the on position the coil and igniter both are getting power. I’ll check out the ignition switch tomorrow, if that is the issue can a locksmith rekey the new one to match my old key? Thanks.


#8

You don’t have to worry about getting a new key. The ignition LOCK (the key part) and the ignition SWITCH (the switch part) are two, physically, separate parts. The ignition SWITCH is held on by one, or two, little screws. Yours has a 6 inch long bundle of wires and a single wire, with connectors (“plugs”) on them. Look for the two inch white plastic cap on the ignition SWITCH. Disconnect a battery cable, first. The plastic panels under the dash, and on the steering column are ALL you have to remove. Ignition SWITCH price: $40 to $70.


#9

You don’t have to worry about getting a new key. The ignition LOCK (the key part) and the ignition SWITCH (the switch part) are two, physically, separate parts. The ignition SWITCH is held on by one, or two, little screws. Yours has a 6 inch long bundle of wires and a single wire, with connectors (“plugs”) on them. Look for the two inch white plastic cap on the ignition SWITCH. Disconnect a battery cable, first. The plastic panels under the dash, and on the steering column are ALL you have to remove. Ignition SWITCH price: $40 to $70.


#10

Thanks, after I posted the last time I read in my service manual it is separate. Once the dash covers are off I just put the key in the acc. position and use a small screwdriver to push the retaining pin on top and the lock cylinder pops off. My local parts store has the switch for 34.99, so hopefully this will resolve the issue. I don’t get how the switch could be messing up for over a year without any other issues with it, but you never know with cars. Thanks.


#11

I didnt mean to post the same thing twice. I must have accidentally brushed my touch pad, before or after. Anyway, it seems like you are trying to change the wrong part. Don’t change the lock cylinder… change the SWITCH. Two little screws and disconnect two electrical connectors is all there is to it. All together, now, say, “SWITCH”!


#12

Replace the ignition coil, when it gets hot it opens either the primary or secondary windings, thus you have not spark to the plugs.