MPI 190 Viper won’t start

[jaydaniels]

Brother in law has a mpi 190 viper that won’t start when come. Battery checks out, sled cranks over, fuel pump comes on but just won’t start. Tried adjusting the fuel ratio for idle and after leaning it out some all of a sudden it just fired right up. Thought problem was fixed. Now today -18c and it won’t start. Tried richer and nothing. Tried lean and a slight kick but won’t start. Once sled is warm it seems fine. Any ideas? Maybe Contact MPI?

 

[murdered141]

Try giving it some throttle while cranking, it works for me especially if its real cold.

 

[jaydaniels]

Try giving it some throttle while cranking, it works for me especially if its real cold.

Thanks, tried that. Still no luck. After some reading seems a lot of people have some issues with Vipers starting.

 

[grizztracks]

in -18C conditions there is a possibility of relay freeze up. Most are thinking because the fuel pump runs they are OK but unlike the Yamaha electronics the Arctic Cat electronics requires two relays to be working in order for it to start. Have you checked spark when it doesn't start? Along with the fuel pump relay they also need the ISC relay (main relay) working to power the ignition and injectors. I changed all my relays out with what is suppose to be a better sealed mechanical relay and with them installed my Viper hasn't had an issues in colder temperatures.

 

[yamahaguy]

If you're thinking its a mpi issue just reconnect the wire harness back to OEM bypassing the gems and use this as a starting test only don't driive it. This will tell you if you're starting issue is with gems or something else on the sled. My guess is something else.

 

[jaydaniels]

in -18C conditions there is a possibility of relay freeze up. Most are thinking because the fuel pump runs they are OK but unlike the Yamaha electronics the Arctic Cat electronics requires two relays to be working in order for it to start. Have you checked spark when it doesn't start? Along with the fuel pump relay they also need the ISC relay (main relay) working to power the ignition and injectors. I changed all my relays out with what is suppose to be a better sealed mechanical relay and with them installed my Viper hasn't had an issues in colder temperatures.


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This sounds like it could be y we’ll be the issue. Next time it won’t start we’ll check for no fire. Thanks.

 

[jaydaniels]

If you're thinking its a mpi issue just reconnect the wire harness back to OEM bypassing the gems and use this as a starting test only don't driive it. This will tell you if you're starting issue is with gems or something else on the sled. My guess is something else.

Great idea. Will give this a try also.

 

[Billy Boy]

Mine did the same thing. Crank no start
Took out the isc relay and warmed it up. Started right up. Had this issue with the starter relay last year so I wired in a solid state relay. Problem gone. Guess I'll put a solid state relay on the isc.

 

[jaydaniels]

Been doing some reading and seems vipers have starting issues with minor voltage issues. The battery on this viper will only hold 12.1 volts. My new sidewinder battery holds almost 12.7. We switched batteries and sled started. When load testing battery it shows fine but after charging drops to 12.1 volts. Could this be a battery use causing the no start?

 

[Alsim]

in -18C conditions there is a possibility of relay freeze up. Most are thinking because the fuel pump runs they are OK but unlike the Yamaha electronics the Arctic Cat electronics requires two relays to be working in order for it to start. Have you checked spark when it doesn't start? Along with the fuel pump relay they also need the ISC relay (main relay) working to power the ignition and injectors. I changed all my relays out with what is suppose to be a better sealed mechanical relay and with them installed my Viper hasn't had an issues in colder temperatures.


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Is it good as the solid state ?How many relays did you change ? Is it the same parts number like for all that you changed ?

Thanks !
303-1AH-S-R1-12vdc

 

[grizztracks]

I wouldn't say it's better or equal to a solid state relay but according to the specs it sealed better than the OEM relay. The "C" in the OEM part number indicates a Flux tight seal and the "S" in the update that I'm trying indicates it's Sealed and Washable. There are five relays in the Viper that this will replace. The only two that aren't replaced are for the reverse and forward shift. I'm not sure if this "C" relay is the answer to the freeze up problem but for the price it's worth a try and the old ones can be kept for spares if needed. As far as I know I'm the only one testing this relay so it would be interesting to see how others that have had issues would make out with it.

 

[grizztracks]

Been doing some reading and seems vipers have starting issues with minor voltage issues. The battery on this viper will only hold 12.1 volts. My new sidewinder battery holds almost 12.7. We switched batteries and sled started. When load testing battery it shows fine but after charging drops to 12.1 volts. Could this be a battery use causing the no start?

The resting battery voltage is important but what's more important is the voltage that the battery maintains under load. Measure the battery voltage while cranking to see how low it drops. Typically you don't want anything below approximately 9.5 volts. I believe with Yamaha's most recent flash update that load voltage is monitored and if it's to low the ECU will shut down the ignition and FI system to prevent a kickback.

 

[Alsim]

The resting battery voltage is important but what's more important is the voltage that the battery can maintains under load. Measure the battery voltage while cranking to see how low it drops. Typically you don't want anything below approximately 9.5 volts. I believe with Yamaha's most recent flash update that load voltage is monitored and if it's to low the ECU will shut down the ignition and FI system to prevent a kickback.

Very good info ! Thanks a lot Grizz. If I understand I will start with the most important for me. The ISC and the fuel pump for the replacement by 303-1AH-S-R1-12vdcb relays .

 

[Yamatuner]

I installed agm deka deep cell battery from remy. It was about $110 but turns over very quick. 15 viper turbo starts easily even well below 0

 

[tcr]

Had a similar problem with my Viper, over a couple years. Started ok above -15 c. -15 to -18 was a hard start and below approx. -18 c no start. Got into the dealer on a cold day while it wasn't starting and was able to check spark: ok, fuel pressure ok, injector pulse ok, compression ok. While trying to diagnose further, sled warmed up enough to start. Replaced battery, reflashed, new synthetic oil, plugs and monitored / attempted to diagnose when cold enough. On the next cold weather trip found richening up before / during cranking, started right up. I used a small propane torch (off) to deliver some propane into the air intake for a few seconds before cranking and when cranking. Fired up immediately just as when warm. Never did find the root cause, always had small propane bottle in the truck for the few days cold enough to cause a problem, worked well.