Something is making it run rich. It was smoking from being rich and it backfired from being rich. The "backfire" is from unburned fuel in the exhaust pipe that gets ignited from the hot gases entering the pipe. You may be having trouble staring it now because the plugs are fouled and the crankcase may be flooded. Remove the plugs and pull it over to help pump the crankcase dry and get some new plugs, probably a bunch because you may fouling them out until you find out what is wrong. One of the first things to try with the old EFI's is a new battery. They are very sensitive to battery condition.
94 Ext Efi Bang! Wont Start
Just got a 94 ext efi that had not been running for a while. I got it started last week and drove it down my street. It ran good but was very smokey due to the old fuel I think. Came home from work and started it today. Started in two pulls. I shut it off and turned it around to drive it outside and buyrn off some of the old fuel. When I pull the rope to restart it let out a HUGE backfire. Pulled it a couple more times and it would grumble a little but would not relly start. Then the handle came off of the rope so I had to open up the recoil and get it out. The darn thing still will not start,not even a grumble now. It has great spark, and is getting fuel, as it will shoot a blue flame if I lay the plugs on top of the holes. Seems to have as good of compression as it did prior to the big BANG but I don't have a compression tester. Also I filled it up with fresh fuel and some injector cleaner (sea foam) after it would not restart and it ran fine on crap fuel before. Any help would be greatly appreciated. Thanks, Garrett
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Originally posted by 94ZR580@Feb 2 2005, 11:38 AM
Something is making it run rich. It was smoking from being rich and it backfired from being rich. The "backfire" is from unburned fuel in the exhaust pipe that gets ignited from the hot gases entering the pipe. You may be having trouble staring it now because the plugs are fouled and the crankcase may be flooded. Remove the plugs and pull it over to help pump the crankcase dry and get some new plugs, probably a bunch because you may fouling them out until you find out what is wrong. One of the first things to try with the old EFI's is a new battery. They are very sensitive to battery condition.
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I think it's batteryless efi. Note part about handle coming off and recoil.
I agree with the rest of the above.
The 94 wasn't batteryless.
Sounds like you probably have a full crankcase, when I was having problems with mine this year I was having similar problems. What I did was completely tore down the fuel system (really not hard at all) and completely cleaned out the tank. Of course, I had a foamy soup in it but in any case having completely brand new gas seemed to help it overcome being so flooded.
Also listen to 94ZR580 about pulling it over without the plugs to help dry out the crankcase. Do this with the ignition OFF btw
A tip for cleaning injectors. Pull them out, fill them up with carb cleaner and apply short little bursts of 12v to the injector leads (no polarity) make sure they click with authority, spray, repeat, etc.
If it still won't run right, I'd check the IAT sensor in the airbox. If the thermistor is bad/dirty, it could mess up the mixture too.
I think that should get you going.
Sounds like you probably have a full crankcase, when I was having problems with mine this year I was having similar problems. What I did was completely tore down the fuel system (really not hard at all) and completely cleaned out the tank. Of course, I had a foamy soup in it but in any case having completely brand new gas seemed to help it overcome being so flooded.
Also listen to 94ZR580 about pulling it over without the plugs to help dry out the crankcase. Do this with the ignition OFF btw
A tip for cleaning injectors. Pull them out, fill them up with carb cleaner and apply short little bursts of 12v to the injector leads (no polarity) make sure they click with authority, spray, repeat, etc.
If it still won't run right, I'd check the IAT sensor in the airbox. If the thermistor is bad/dirty, it could mess up the mixture too.
I think that should get you going.
It does use a battery for the efi but it doent have electric start. I put a fresh battery in last week when I got the sled home. When I pull the plugs the spark is really good and will fire the fuel when laying on top of the head. I'll have to try some new ones anyway.The previous owner also said it has a chip in it. Where is it located and can I put it back to stock? Thanks, Croc
Sorry. Thought all Cat's were batteryless unless electric start.
My Bad.
My Bad.
Batteryless came about in 96 or 97.
1997Originally posted by GlockMan@Feb 3 2005, 08:09 AM
Batteryless came about in 96 or 97.
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chicksdigwagons, Could you give me ashort explanation on where the IAT sensor and thermistor are located? I took the injectors out and cleaned them like you said. I haven't tried to start it since because I'd like to check the other two things before I put it back together. Is there a way to test the sensor and thermsitor, or do I just have to trouble shoot by replacing with new? The sled has 3,600 miles on it. Also where would the "chip" be that the previous owner had installed and can I take it out and return to stock? I heard not all of the chips are ethanol friendly and can make the sled run like crap if the wrong fuel is used. Garrett
The IAT and thermistor are one in the same. IAT = Intake Air Temperature. Its a little sensor in the top of the airbox, two black wires coming out shaped something like <O> that I guess. :slick:Originally posted by croc@Feb 3 2005, 06:07 PM
chicksdigwagons, Could you give me ashort explanation on where the IAT sensor and thermistor are located? I took the injectors out and cleaned them like you said. I haven't tried to start it since because I'd like to check the other two things before I put it back together. Is there a way to test the sensor and thermsitor, or do I just have to trouble shoot by replacing with new? The sled has 3,600 miles on it. Also where would the "chip" be that the previous owner had installed and can I take it out and return to stock? I heard not all of the chips are ethanol friendly and can make the sled run like crap if the wrong fuel is used. Garrett
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It's held in by little clippy things, all you need to do is yank on it and it will come out. It should be clean, not black and sooty or dirty. To test it you need to compare the resistance between the two leads relative to temp. In the service manual, there is a chart of temps. For example, at 72 degrees F, the resistance should be ~2359 Ohms.
Looking further into my literature, there are several sensors that could be fudged up...the one PITA about EFI. As for the chip, its under the gold cover on the ECU above the battery. Yes there are different chips for different fuels, etc. Plus aftermarket, easy to swap if you can find the right chip.
Not really being completely coherent, but I hope it made sense.
-Brad
I thought that was probably the sensor but wanted to make sure. I opened up the air box today also and there was some gray sponge pieces in it so I cleaned it all out. Is there supposed to be some kind of filter? If there is I think the mice got to it. :cussing: Where can I buy that service manual you are talking about? If I get that then I can go through all of the different sensors and maybe figure this thing out. I must say I'm having fun wrenching on this thing and learning a bit about this EFI system. Its really not that complicated, it just has alot of sensors and such. Thanks for all the help so far, Garrett SWRules
Hi all I have a 1994 arctic cat ext 580 efi I have problems with it running for a while then all of the sudden it will jump up to almost 5000 rpms then it will stay there for a bit then it just dues and I can't get it to restart. I've replaced the voltage regulator, tps sensor, fuel pump as the the original was seized, I've also replaced both relays and the injectors are getting fuel through them. Any thoughts I'm getting real tired of thus sled and du.ping money into it nit sure what is causing my issues?
stator is known to fail on these.
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