Immediately Stalls if it even starts at all

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Cwhite7089

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I'm at my wits end with the truck.


1995 K1500 Z71 5.7 TBI
164k miles


Ran, albeit like crap, then I parked it to fix the intake manifold leak, ended up having to replace the distributor and set timing and it ran for 5 minutes but died under any amount of load at all, whether it was turning the steering wheel accidentally or later putting it into gear.
The starter then failed, that was in March.


Tuesday night I replaced the starter and got 2 starts out of it, but it would immediately stall and die. No fuss, just die.
Then it grinded with short abrupt stops in its attempt to start 3 times, then nothing at all, wouldn't even turn the starter over. Wednesday I go to finally replace the bad plugged up Idle Air Control valve and have a mobile mechanic come look at it and the only thing i found out is that one of the wires to the starter is melted, both the new and old starter both work great though, and can't even diagnose the stalling issue. Won't run long enough, and not at all during the time the mechanic was over there.
Possibility of a fried engine computer?, maybe even ignition switch though that doesn't explain the fact I still get plenty of fuel and the dying under load specifically


So many possibilities still despite ruling out timing, Spark, fuel, vacuum, and most sensors and emissions related valves. So much has been replaced, most of it needed it but still not one single bit of progress, only worse and worse.



So I'm running out of ideas, patience and spare money and hoping for any sort of ideas or leads

It's getting desperate


And no, in my local market, getting another car doesn't make sense. For one I still owe money regardless and secondly any vehicle I could ensure has less issues, less not none, is $4k+


I'm about to pull the ecm and make sure it isn't fried or faulty, I'm gonna have to borrow a multimeter at that, I'm vastly underequiped but have to make things happen. If it's not the ecm, I'm ready to pull out my hair and scream till I tear vocal chords
 

someotherguy

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Very, very low chance of it being the PCM's fault. Bottom of the list of suspects right next to low air pressure in your spare tire being the cause.

Has fuel pressure been checked, with a gauge? What's the pressure? What activity are you calling "getting plenty of fuel" ?

If someone calling themselves a mobile mechanic couldn't make progress past identifying a melted starter wire, they sound more like someone that goes around doing oil changes and brake jobs. Nothing wrong with that except maybe they should have been more upfront about their skill level.

Where.. in Texas are ya?

Richard
 

Cwhite7089

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Before seeing this I did investigate the pcm, pulled it out and opened it up, 2 blown capacitors. Still researching other things while another is on the way, as my next step.

As for the fuel, it sprays perfectly fine as if running normally, the pump does build pressure every time you start it but the pressure has been checked and while I don't have the number off the top of my head anymore, it was what it should be

And I'm in Wichita Falls, near the border with Oklahoma. This place sucks haha
 

someotherguy

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Wow! Blown caps in the PCM. Unusual. Were they electrolytic caps? Maybe just finally got old enough and failed, and something we may see more of in the future. Another thought is if those are in part of the injector driver circuitry, maybe you have a short/intermittent short in the injector harness. The wires at the TBI going to the injectors are known for getting brittle and the insulation breaks off. Also on the earlier trucks with the metal spacer ring (before they switched to phenolic/plastic/whatever around 1994) you would sometimes see the wires chafe on the ring and short out on it. Maybe a previous owner over-fused one of the ECM circuits.........?

I've been through Wichita Falls. I feel ya..

Richard
 

Cwhite7089

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Wow! Blown caps in the PCM. Unusual. Were they electrolytic caps? Maybe just finally got old enough and failed, and something we may see more of in the future. Another thought is if those are in part of the injector driver circuitry, maybe you have a short/intermittent short in the injector harness. The wires at the TBI going to the injectors are known for getting brittle and the insulation breaks off. Also on the earlier trucks with the metal spacer ring (before they switched to phenolic/plastic/whatever around 1994) you would sometimes see the wires chafe on the ring and short out on it. Maybe a previous owner over-fused one of the ECM circuits.........?

I've been through Wichita Falls. I feel ya..

Richard
Yes the orange ones. I'm not sure what system they were part of but definitely wasn't doing me any favors. I will continue to check what I can but its coming down to fuel pressure and wires behind the motor that I can't see or reach
 

Cwhite7089

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So apparently my fuel pressure is fine too and it's looking more like I had an overload somewhere in the harness especially the ignition part. Probably some backfeeding. Gonna take a look at my ignition switch first since I know it was a cheapo amazon one before I bought the truck
 
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