strange problem, 2012 M8 turbo.

bgraff1 · Nov 12, 2012

hey guys i have a strange problem here. i have a 2012 m800 with a CPC stage 2 turbo. about a month ago i pulled the top end to check and i replaced my reeds and then re assembled. soon after the whole sled was torn down for a tunnel replacement and powder coating. well i finally got it together tonight and it fired up after a few pulls and seemed to run fine. then it died. i did as much searching as i could and cant find anything wrong with the wiring. when i have the kill switch in the running position i get full spark but it wont build fuel pressure. if i move the kill switch to the off position i get no spark but it will build my normal fuel pressure. so obviously the sled wont run and i have no idea why. anybody have anything i should check here? thanks

Whimp · Nov 13, 2012

Did you hook your ground back up on the steering loop support under the water bottle?

bgraff1 · Nov 13, 2012

all ground wires are securely attached.

RACINSTATION · Nov 13, 2012

Where the chassis was just powder coated, I would still check all the grounds to make sure that you sanded or ground off the powder coating. If you did not, it will not make a good connection.

bgraff1 · Nov 13, 2012

i will double check but nothing under the hood was coated just bumpers, skid etc. the new tunnel was a take off from a LTD so it would be good already. thanks for the help guys.

bgraff1 · Nov 13, 2012

well i checked grounds and the only grounds are 2 wires on the frame above the chain case. removed the tether and put to stock to try, installed the hood and gauges but nothing helped.

RACINSTATION · Nov 13, 2012

Unplug your engine stop switch and try that.

Whimp · Nov 13, 2012

I'd check to make sure you didnt put a rivot or screw or dill bit through your rear brake wires. If you teaked one and it is grounding out it would act like this.....man these issues can be frustrating....

quick way to check this is to unplug the rear brake harness right above the brake disc....see if it changes anything.....

Whimp · Nov 13, 2012

Is one of the grounds you are refering to underneath the water bottle? It is tucked back in there and can be way hard to see unless you know where it is.... It is on the back of one of the bolts that hold the steering support brace.... If you replaced a tunnel you probably removed this ground...

bgraff1 · Nov 13, 2012

Checked everything over. Tried disconnecting tail light with no luck. Also disconnected secondary injectors and hooked everything up stock and still won't fire. I'm pretty sure it's getting fuel as after a bunch of pulls I can see fuel in the charge box. I get around 17 psi fuel pressure when I pull over with the kill switch "on" and 32 psi pressure with the kill switch "off"

m8magicandmystery · Nov 13, 2012

for some reason something is interacting between your kill switch and fuel pump wiring i would venture to say..check your fuel pump wiring..

bgraff1 · Nov 14, 2012

Whimp said:
Is one of the grounds you are refering to underneath the water bottle? It is tucked back in there and can be way hard to see unless you know where it is.... It is on the back of one of the bolts that hold the steering support brace.... If you replaced a tunnel you probably removed this ground...

interested in this ground your talking about, can you explain where this is because i cant recall one being there, but i also cant exactly picture where you are talking. thanks.

Rixster · Nov 14, 2012

"installed the hood and gauges but nothing helped. "

So did you run it with the hood off at first? no headlights or gauges? You may have fried your ecu. It doesn't take long.

msutton4181 · Nov 14, 2012

check all the fuses i had a problem with mine. cpc said its rare but you might check anyway. it will have to do with the voltage regulator circuit i believe

bgraff1 · Nov 14, 2012

ive ran it multiple times since ive bought it with no hood on and never have had a problem, done it on other sleds too without a problem. all fuses are good, i checked that.

Daltech · Nov 14, 2012

No problem running without hood. Done it several times.
I had start up on mine today after full powdercoating. No problems.
To make sure i had a good ground connection, I did grind away some paint under the bolts that hold the chaincase to the tunnel. Since ground wire are attached to the chaincase, you have to be sure that chaincase also has a good ground connection to the frame.

bgraff1 · Nov 14, 2012

there is a ground wire attached to the chain case? i have grounds attached to the brace that goes from the chain case to the steering post but nothing attached to the case its self. the tunnel i installed was a factory take off so im sure if it worked on the old sled it should work on mine?

Daltech · Nov 14, 2012

bgraff1 said:
there is a ground wire attached to the chain case? i have grounds attached to the brace that goes from the chain case to the steering post but nothing attached to the case its self. the tunnel i installed was a factory take off so im sure if it worked on the old sled it should work on mine?

Yeah, it connects to the brace, where the brace are attached to the chaincase. I have paintet my braces, and had do grind away powdercoat there also.

Sent from my GT-P7510 using Tapatalk 2

Whimp · Nov 14, 2012

true true

sidehill · Nov 14, 2012

Dont know what all Dale sent you for a jumper wire for the fuel pump. If it is the same as mine you will have a jumper to power the fuel pump. Disconnect the plug at the jumper and charge the fuel pump up with a 9 volt battery then start the sled and test to see if you have power to the fuel pump pigtail while the sled is running. It will only run for 15 seconds or so then you will have to charge the fuel pump again with the 9 volt battery.

This will tell you if your fuel pump is ok and also that you have power to the pump when the sled is running. I am sure you have checked the power wire for the pigtail that runs the fuel pump.

strange problem, 2012 M8 turbo.

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