[TrailStar500]

Hi, my 2021 ZForce does not prime and does not start.
Last time when it ran, it back fired and seemed down power a bit. Cranks great..
Checked fuel pump fuse, looked good.
Swapped fuel pump and aux relays no change
Checked both main fuses under driver seat, both good.
Got fuel, even took 12v direct to pump and felt it spin.

Engine cranks but won’t start …. Any ideas?

[NMKawierider]

It could be lots of things including a valve timing jump but...one of the most common issues is with either the key switch or...the notorious kill switch, which controls the fuel and ignition systems..which is also like the rest of the rockers, not water proof. As such is susceptible for moisture getting in and corroding the contacts. Many have had to replace them but a few have been able to work the switch a few times and got to to work again...for a while. If the kill switch and the key switch tests-out OK then I might take a look ate the AUX relays and the CPS aka engine speed sensor. Pull it and see if there is any trash on the tip. All in the hopes it didn't jump time so after that I would check the valve timing.
     

[TrailStar500]

It could be lots of things including a valve timing jump but...one of the most common issues is with either the key switch or...the notorious kill switch, which controls the fuel and ignition systems..which is also like the rest of the rockers, not water proof. As such is susceptible for moisture getting in and corroding the contacts. Many have had to replace them but a few have been able to work the switch a few times and got to to work again...for a while. If the kill switch and the key switch tests-out OK then I might take a look ate the AUX relays and the CPS aka engine speed sensor. Pull it and see if there is any trash on the tip. All in the hopes it didn't jump time so after that I would check the valve timing.
     

I thought about valve timing but then I should hear the fuel pump prime right? And then it wouldn’t start.

I don’t think I have 12v going to the pump when I key on and turn on the kill switch. These units usually prime and it is not.

While cranking I think I get 12v to the pump.

I have checked fuses and moved relays around to test with out finding anything new and fuses seem good.

Wondering if the kill switch is bad, but usually those also block cranking, I am going  to try and bypass or test that next, any tips for getting the switch out of the dash panel? Will look at that next.

I did swap fuel pumps with no change in behavior ….

[NMKawierider]

The rocker switches are like all the rest- they all have their locks on outer edges on each ends so just slip a thin flat edge as wide as the switch under the lip and push in..then a slight twist to lift it out.

[Grandmaster Splash]

Hi TrailStar 500,

Sounds like a typical kill switch circuit issue to me.

If the pump is not priming then its not getting 12Volts, especially if you have checked the pump independently.

However, check the full start circuit electrically sometimes they have 2 or 3 relays fitted, some can be mini relays which are prone to issues.

Locate where the pump gets it feed from on the start circuit .......follow and check this element of the circuit.

GMSAHFR

[TrailStar500]

Well a new kill switch didn't do it .... more multi-meter work ahead for me ..... grrr. Any other suggestions would be welcome.

Time to trace the cables from the relay to the fuel pump.

[NMKawierider]

Run back through what happens when it has sat for several hours and you try to start it. First turn the key to the run position and the wait for the pump to run and stop. What do you hear? Then turning the key to the starter position. Does it turn the engine over without starting or does it do nothing. If nothing does it click?

In all this is it in neutral and is the neutral light ON? Have you tried holding the brake on while trying to start it? 

[TrailStar500]

Run back through what happens when it has sat for several hours and you try to start it. First turn the key to the run position and the wait for the pump to run and stop. What do you hear? Then turning the key to the starter position. Does it turn the engine over without starting or does it do nothing. If nothing does it click?

In all this is it in neutral and is the neutral light ON? Have you tried holding the brake on while trying to start it?

Ok - quick recap -
Was running great. Last night of a trip, ran great seems to maybe have backfired as I went to park it. All good.

Next morning - maybe heard a tiny amount of the normal prime, but did not prime. Cranked, plenty of battery but never started.
Troubleshooting - never hear prime of the pump with kill switch on and key turned right. No voltage at fuel pump unless I crank.
Changed battery, swapped fuel pump relays around ... do not have a new one (ordered now)
Replaced kill switch
Still no prime at key on.
I did switch fuel pumps and both with direct 12v work but they do not prime.
Engine cranks but no spark.
I think I need to understand why no prime ....feels electrical.

I thought kill switch was issue ...

[NMKawierider]

With no spark it will never start anyway..fuel or not. Wondering if they ever put a roll-over sensor on these. I'll check. I guess get the wiring diagram and start tracing. Probably just a bad connector somewhere. 

[NMKawierider]

Might take the return like off and see if it pumps. If do there is an issue with the pressure switch. I don't see any roll-over sensor in the diagrams so..Test the key switch. If it isn't sending power to the AUX relay(s), nothing is getting power.

[TrailStar500]

With no spark it will never start anyway..fuel or not. Wondering if they ever put a roll-over sensor on these. I'll check. I guess get the wiring diagram and start tracing. Probably just a bad connector somewhere.

Do you have a link to the wiring diagrams?

[NMKawierider]

With no spark it will never start anyway..fuel or not. Wondering if they ever put a roll-over sensor on these. I'll check. I guess get the wiring diagram and start tracing. Probably just a bad connector somewhere.

Do you have a link to the wiring diagrams?

Sorry, nope, not for a 2021. That would be a dealer item I believe. Might try Google though.