PCM ZR6 Engine issues

I have A 2003 AIR NAUTIQUE with ZR6 PCM ENGINE. When I first got it it would run for 30 minutes then stall. I would have to let it sit for 10 min then would run for 5-10 minutes and that would continue until I got it back on trailer.
Replaced fuel lines, 3 relays on top of engine, PCV valve, jumped kill switch, anti siphon valve, checked vents.
Fuel pumps got changed when I initially got it.

The barely starts now and idles rough for 10-20sec. I get a check engine light.

I bought the diacom software and scanned it. No error codes. It does give a malfunction alarm light on. I also recorded run while briefly starting. Voltage looks to be dropping for some reason.

Is there anyone I can send recording to to help me figure out what is wrong?

voltage dropping by how much...??? if it gets low enough, computer stops = engine stops!!

if you have the check engine light= ON, the computer has detected something 'out of bounds' and almost always sets a DTC (aka a code).

The diacom software is the 'industry standard' and has a proven track record....you do need the correct cable connections.....assuming that's ok - does the balance of the displayed parameters make sense?

Finally, the computer doesn't control/monitor everything the engine needs to runs.....so, the issue could be outside of the computer's "field of view"....maybe check the basics as well as the electronics...??

Voltage drops to 9v. I had batter and altenator checked today and are good.
What could cause voltage to drop

9vdc on the computer? that won't work well...I'd suspect the main harness connector may be corroded...could also be a relay socket connection..

if that's not it, time to get the volt meter and check for voltage drops.

Harness meaning main Hermes that goes to computer or wire to battery

main harness though it wouldn't hurt to check the ECU harness connectors as well..

Still cant get it
Alternator checked good
Replaced battery
and main wire from battery to starter because terminal connector broke.
Went though all electrical connections and are good
Found exhaust fan had ripped wires apart I repaired and put back together.
I still get low voltage when trying to start. Voltage is good and then I try and start and it drops to 9-10V
I could find voltage issue if I new where to start but I don't have a wiring schematic
Any thoughts out there?

bummer on the fan's handywork......

ground wire - both battery end and engine end (common culprit).

Guess the first question is where/how are you measuring the voltage??

A DC device needs a complete, low resistance path to work correctly - this means the "ground'' side as well as the 'hot' side....and back connection in either side will cause a voltage drop....

I am guessing best way to test this would be using ohm meter from negative on battery to engine block surface?

NO!!

Use a DMM but on the low DC VOLTS scale....the OHM setting doesn't really check for a crudy connection (very low current). and see what happens during the startup...a 'healthy' installation will have ~ 1/4 VDC drop between battery and block during cranking - all else being 'normal'

makomark said:

NO!!

Use a DMM but on the low DC VOLTS scale....the OHM setting doesn't really check for a cruddy connection (very low current). and see what happens during the startup...a 'healthy' installation will have ~ 1/4 VDC drop between battery and block during cranking - all else being 'normal'

Click to expand...

Was the battery "load-tested" properly? I had a similar issue and it turned out I needed a new battery. Double check wiring harness for a stress crack - maybe a place where the wiring goes around a turn or is bent. This sounds like bad ground or wire somewhere and it may take meticulous study of wires to find it. Don't throw any more parts at it.

Ken

while cranking feel wires for heat,usually means corrosion inside of wires "cables"