LT Texan

Man, this thing is STILL not up and running!!!!???!

Thankfully, I have an old bugger. Not much to go wrong.

chewy8000

No real updates except I swapped out and tested the ECU and the L-jet with some spares Hacker was kind enough to send. Changed nothing still have the problem.

Here is the updated list:
New igntion switch
New fuel pump
New fuel filter
New ignition relay
New fuel pump relay
New temp II sensor
New thermo time switch
New cold start injector
Cleaned ground (block to frame)
Cleaned ground (battery to frame)
cleaned ground (behind CE panel)
New starter
New battery
cleaned replaced all fuses
Cleaned AFM (springs fine working normal) resistance test was fine
Used Auxiliary air valve resistance test was fine
swapped out and tested ECU with spare
swapped out and tested L-jet with spare

anything else left to test?

Landseer

There are more grounds to clean then are listed that are crucial. Did you get them all?

chewy8000

Pulled the CE back and replaced all of the fuses and removed and cleaned all the grounds back there against the firewall with emery cloth. Any others?

dr bob

Put the voltmeter on coil terminal 15 and see if there's power there with the key in the run position.

Landseer

These are crucial:

The ground under the car, passenger side, a cable connecting block and frame.

Another (might be split into 2) under the passenger side cam cover that grounds ignition harness components and I think that includes brain, to the block. It stems from the injector harness near the passenger side firewall.

Then there are four more. Not sure if they can contribute to a no start.
Under pod, seen looking up while laying on your back with head on the brake pedal. Front left of radiator. Front right of radiator. Behind passenger quarter panel near taillight.


The grounds can even show continuity across them, but not be clean enough to allow passage of enough current. If loose or corroded, they can contribute to intermittant behaviors as you hit bumps or draw more or less current through the subsystems.

dr bob

Continuing, a few folks have experienced failure of one of the two resistors used in the igniton circuit. There's one between the ignition 15 bus and a supply contact on the starter solenoid, another between that starter solenoid contact and the coil terminal 15 itself. In "run" position, power for the coil is supplied through both resistors. In the 'start' position, the first resistor is bypassed, and ignition coil power is supplied through just the second resistor from the auxiliary contact in the solenoid. Symptom is that the car will crank, and will fire while cranking, but no more ignition after the key is released from 'start' position.

Cause of that primary resitor failing can be careless/accidental connection of the battery lead and the aux contact wire on the starter solenoid, or dying ignition switch when 15 contact no longer works. Or just old age. The problem persists after ignition switch replacement.

chewy8000

Thanks Dr. bob,

Does anyone have a picture of these resistors so I know what to look for?

Thanks

Dean_Fuller

Just a thought...I replaced an old ignition switch with a new one that was bad. I kept discounting it as an issue because it was new. Swapped in another new one and all was well. Your windows not working 50% of the time could be a sign.

Landseer

More great points. All of which have taken these cars down at times.

I'll go snap a picture of the resistors for you.

hacker-pschorr

Two round / tube shaped things bolted to the inner fender on the drivers side, kind of below the coil.

Same location as the ignition brains, just the opposite side.

During some troubleshooting a few years ago I simply attached a jumper over each resistor. Drove around this way for a few days.

Maybe I missed this, but have you tried a different coil?

Landseer

Resistors, left fender well near front.
They have resistance marked on them, IIRC.

Landseer

Be sure to clean that ground located on the passenger side cam cover.

IcemanG17

Chewy
http://members.rennlist.com/sharkski...leShooting.htm

Dave's write up is great...I would follow it step by step...

On the recently dead 84 Lemons racer....the no start is the resistors.....I checked the resistance and one is about 4x as high as it should be..... that and the coil is reading a bit odd too.... Resistors are $56 for both and a new coil is only $68...I would change them all at once

chewy8000

Update!!!!!!! Grounds grounds grounds!!!!! Landseer I owe you a beer if we ever meet. I didn't realize the aluminum fuel rails I had bought from Tony came with injector hold down brackets that were painted. Cleaned up the two injector grounds mounted them to the old smog pump bracket mounts in the cam box and she fired right up! I can't thank everyone enough for the support and troubleshooting. Just in time for spring. Ground must have been enough to run for a month or so then crapped out.