Intermittent start need some help

[noid]

I am having an intermittent start that I am trying to diagnose.

Symptoms:

1. Will Crank but in no way stutter or attempt to start
2. Out of no where it will start perfectly
3. If I turn the ignition to "ON" and I do not hear the ICV buzz then I know almost certainly that the car wont start. When I turn the key and hear the ICV buzzing almost always the car WILL start.
4. Once running it will stay running without fault.

Because of number 3, I doubt it is the CPS. It seems to be an initialization problem, where if I turn the key and the conditions are "right" it will start, if I turn the ignition and the conditions are "wrong" it will not start.

[noid]

More symptoms:

When in acc mode on the ignition, if the icv is buzzing, the check engine light is lit ( as it should be in acc mode with every other light). However when the icv does not buzz the check engine light also goes out in acc mode.

So it must be something feeding the dme and icv
. I am thinking of checking the ignition and DME.

Intermitently jiggling the steering wheel makes it go from good to bad. Thinking it may be a ground.

[noid]

Main relay harness pins 30 and ground alwayd show battery voltage.

86 and ground show battery voltage when working and 2.7 volts when not working.

[tsouth]

Definitely start with the simpler things first. Perhaps use some electronics cleaner and give the inside of the icv a few sprays? It's good to see you testing and not throwing parts at it. You're on the right track and will surely get there soon enough. I'm sorry I don't have more insight to the issue, but atleast let this comment serve as words of encouragement! All the best

[101]

"Intermitently jiggling the steering wheel makes it go from good to bad".

This makes me think you may have a bad electrical portion of the ignition switch.

One wire off that switch feeds 12V+ to both the coil and the DME. If that circuit opens, neither the coil or the DME are getting what they need and the car will not fire up.

The DME feeds the ICV. No power to the DME no power to the ICV.

First thing I'd do is see if you have spark when the engine won't fire up.

Then break out your voltmeter and test the voltage between the 12V+ terminal on the coil and ground as well as pin #27 on the DME harness and ground. If both are acting the same way - (i.e., no voltage present when the car will not fire up) - you've significantly narrowed down the cause.

Good luck!

[noid]

"Intermitently jiggling the steering wheel makes it go from good to bad".

This makes me think you may have a bad electrical portion of the ignition switch.

One wire off that switch feeds 12V+ to both the coil and the DME. If that circuit opens, neither the coil or the DME are getting what they need and the car will not fire up.

The DME feeds the ICV. No power to the DME no power to the ICV.

First thing I'd do is see if you have spark when the engine won't fire up.

Then break out your voltmeter and test the voltage between the 12V+ terminal on the coil and ground as well as pin #27 on the DME harness and ground. If both are acting the same way - (i.e., no voltage present when the car will not fire up) - you've significantly narrowed down the cause.

Good luck!

The jiggling theory may not be accurate, in the last hour I have not been able to recreate the effect.

What I have observed is the main relay connectors pin 86 volt dropping to 2.7 volts from battery voltage when ignition is on. Which it shouldnt it should stay at battery voltage.

I now have to trace the problem from pin 86 to whereever it goes.

[noid]

Confirmed dme is not getting power also.

Problem must be between dme and ignition switch.

I will be removing the ignition switch to have a look.

[shoshottz]

@noid can u plz tell me if u fixed this problem or not and how?

thanks.


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[noid]

I did fix the issue. It ended up being the DME Main relay.

It was on the edge of working and not working. That is why it was so intermittent.

The easiest way to tell is by looking at your check engine light. If it lights up while in accessory mode, that means your DME relay is allowing your DME to power up and therefore engage the light. If it doesn't light up you know your DME isnt powering up.

[shoshottz]

Intermittent start need some help

ok thanks bro, ive replaced mine already actually 🤦🏿waffles♂️ , so on to the fuel pump relay and 02heater relay...let ya know if its fixed after i replace.


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[shoshottz]

car started and ran champion like for a week till this morning.

changed the
fuel pump relay
02 sensor relay
dme relay
02 sensor
cps

whats next [emoji52]


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