You have fuel pressure to the rail. That doesn't prove the injectors are actually firing.

But if you're not getting spark, you certainly have to fix that. May as well concentrate there.

A bad ignition switch will cause BOTH fuel and spark to stop when the circuit is interrupted.

 

Jim, I plan on checking for the voltage with the key cranking on Sunday. I just changed the coil, to no avail. I have now changed:
- ICM
- Coil
- Wireset
- Cap and gasket
- Main relay

I plan to check the plugs themselves, as I found oil in the cylinder that the wire set plugs into on 2 of them, 1 worse than the other, and I think these theoretically should be dry, correct.

Any other ideas? I'm totally stumped :/

Thanks!

 

Yes they should be dry. Sounds like the tube seals are leaking.

While looking at it, check the ground (G101) on the end of the TB/plenum just to be sure it is clean and tight.

 

Hey guys, back again. I'm still completely clueless as to what's wrong with the car, and I took it to a dealer that wanted to charge me over $1k for general maintenance before they even got to figuring out what the problem was. So... I'm back to doing this myself, can't deal with dealer bull*#@t.

In any case, has anybody ever heard of a problem like this? Everybody seems to know of this problem existing in heat, but not in cold weather. I'm getting kind of desperate to fix this... Is it worth replacing the distributor itself? Just to reiterate, I am not getting any spark out the coil in cold weather. To the best I can see, it is getting air and fuel, just no spark.

Also, a friend of mine has this portable coil that he can plug into the battery and plug in to my distributor, and it fires just fine. So I'm 99.9999999% sure it's spark, and NOT a lack of fuel or air. Is there anything that can fail that controls the coil? I already replaced the ICM. Is there anything else?

Again, thanks for all your help; really hoping to fix this one soon...

 

A timing light w/ inductive pickup can be used to verify spark is getting to plug. No flash on wire/s means no spark.

Why no spark? shorting to ground is possible through a cracked rotor, about only thing not replaced.

Another good test is to attempt starting car w/ a good dose of throttle body cleaner or starter fluid. If no-start persists, then spark missing is confirmed. If it starts briefly and runs, then somehow fuel is not being delivered.

good luck

 

Alright guys, I have a real conundrum here. I still have no spark, and still only in cold weather. In the late morning, afternoon, it fires right up just like it should.

I have officially replaced:
Distributor
Cap
Rotor
ICM
Coil
Wireset
Main Relay

Is there anything even left? I'm so baffled. A friend recommended looking into something he thought was called a closed loop O2 sensor, or something of the sort. I know O2 sensors exist, but what's the closed loop mean? And can sensors cause a problem like this? I was under the impression that these sensors controlled how much air and fuel were getting into the carburetor, so I don't understand how they could cause spark issues.

Any info or suggestions are greatly appreciated; I really don't know what to do next and I'm getting pretty desperate. Thanks!

 

They can't cause spark issues. Closed-loop is the manner of controlled operation of your engine's fuel-injection controller. It's not a "type" of sensor.

Your car has 2 O2 sensors, the one up front feeds back to the controller and the controller responds by adjusting the fuel rate. That's called "closed loop". In the first minute or so before that sensor heats up, it can't measure and your controller uses "open-loop" control. That simply means it ignores the O2 sensor for the time being. And that only has to do with fuel rate, not spark.

------

So, there's kinda nothing left (that hasn't already been replaced). Down to looking for intermittent breaks in some wiring between engine & controller. At the distributor, look at the wiring harness connection. Any loose/dirty/corroded pins? I don't know 1997 real well, but others might identify plugs elsewhere in the wiring harness that connect those same circuits.

 

Thanks Jim. So the problem is still no spark, but the weird part is that there is a single, good spark as soon as you turn the key, and then nothing. I was looking at some wiring diagrams and found that the ICM takes two leads, one from the ignition switch, and one from the ECM. From the ECM, the lead was called "Ignition Input Signal." I started thinking about the way the whole system works, and this is the best I could come up with that fits my problem:

Does turning the key give the ICM instruction to fire the coil once, and then the ICM listens to the ECM on instruction to keep giving spark, based on whether or not the engine is turning (regardless of whether or not by starter or engine running)? Is that even a remotely correct concept of the ignition system? This would point fingers at the ECM being the problem, which is what one of my friends suggested, and I usually trust this guy unconditionally on car stuff.

I'm just trying to wrap my head around why the ECM could be involved. Any other thoughts?

Thanks!

 

I don't think it should fire the spark just on turning the key.

The ICM is kinda like an isolation amplifier. It protects the ECM from voltage spikes feeding backwards from the coil.

The ECM uses the "ignition input signal" to command the ICM to fire the coil. The timing of that command depends on the ECM getting timing signals from the timing sensors in the distributor & at the crankshaft. Maybe THOSE timing signals are messed up?

When you replaced the distributor, was it direct/identical? The arrangement of those sensors has changed a couple times over the years. So a distributor from the wrong year might physically fit, but generate the wrong signals. BUT... if that were the case, it should throw some error codes.