[supersaver18]

Hey Ya'll,

I've got a 1995 ZR 580 EFI that I got for 500 from a friend. It runs but it's a ditch banger and it has its issues. The main problem with it is that the engine is limiting itself to 5000 RPM sometimes. It can be immediately upon starting or happen after anywhere from 5-10 min of riding. My buddy swears it has to be the ECU because we checked the stater (no idea how to spell that so you can laugh), CDI, and battery and it has no issues there. The compression tests checked out, it wasn't a hot day so overheating shouldnt be an issue, and all fluids are normal.

I have been searching the web on different forums and notice people referring to the color coded dot on the side of the ECU and that being important. One guy was saying he has yellow fuel injectors so he needs the yellow dot ECU not the blue or red dot ECU. I looked at mine and I have yellow fuel injectors and a blue dot ECU so perhaps that is the problem.

My questions are: Anybody ever dealt with the RPM limiting issue like this and have advice on potential probs and solutions? Can someone tell me what ECU I should have and if it should match the fuel injector plugs? Or point me to a source I can look up to find the info? Thanks.

 

[Remnar]

your ecu and injectors should match. I had a 95 efi that would rev up to bout 4500 then bog and it turned out to be the dropping resistor on the back of the ecu mounting plate. but I would start with replacing your ecu or injectors with the matching color code.

 

[Blaine]

most of the time the ECU won't cause a bog condition....more than likely your issue lies elsewhere. What were the stator ohms? Could be mechanical..cluthcing issue, check compression, check fuel pressure ect..

 

[GregB]

ECU wont matter. its something else.

 

[supersaver18]

ECU/Fuel Injector Pair

Need help starting sled again. I am wondering if maybe I should replace the fuel injectors (for Remnar: which hopefully might fix the rev limiting issue once i get it started?). During troubleshooting one looked good (could see the screen element inside but the other was gunned up and took some scraping to clear some sludge off the screen) which is why I think maybe they are bad? Since Remnar said the injectors and ECU need to match I am thinking of trying to buy some blue fuel injectors (to match the blue dot ECU). Is there a way to tell which color pair of fuel injectors/ECU I should have?

As far as starting troubleshooting: I have a brand new battery, fuel gets pumped all the way to the fuel manifold (might be wrong term but the metal thing that provides the relief valve and also hooks into the fuel injectors). Spark plugs look good (one silver, one somewhat dark but not too corroded) and both get blue spark when I observe after grounding it to the case. Fuel in the tank is about a year old but smells like Gas and lights on fire (tested lol) plus I added Stabil to it and the sled just started a week ago with the current fuel in it, so pretty sure it isn't that.

So I was out of the country for almost a year and could not troubleshoot the sled and now want to just get my money back out but it wouldn't start. (turned out it was a combo of bad battery and subsequent not plugging a connector back in after replacing said battery). I offered $100 to someone who could get it running since a running sled is way more valuable than a parts sled. Someone came and figured out the problems and started it. I went out the next day to use it and it fired up. I left it idling and came back 10 min later to it being shut off. I started it again and figured maybe it just needed some power to the engine to get everything working again so I attempted to give it some gas to see if it would move and it got up around 3500 and just sputtered out and died. Subsequent attempts to start were futile. Thought maybe I flooded it so I tried to start it a few times with the fuel hose pumping into a milk jug (good pressure it seemed) and pull started a few times. Waited a day (with battery tender on overnight in case temps dropped) and again no luck. The guy I paid to start it just so happened to leave AK so he isn't around unfortunately.

At this point I would be very happy to get $300 for it and take the loss of 350 (Bought for 500, paid 50 for battery and 100 for troubleshooting help) and just want to limit the amount of money I continue to throw at a dead end. Thanks so much guys! Sorry for the long-windedness.

 

[supersaver18]

Also, I still need to check compression, fuel pressure, and stator ohms but don't have those tools myself and need to find someone to borrow them from. Lastly, the sled was sitting there and did have quite a bit of snow/ice around and in it. I did check the belt to make sure i didn't burn it trying to get the sled out of its spot (since it was stuck in about a half inch of ice from freezing rain) but the belt is fine and I have moved the sled so that it is not stuck on the ice buildup anymore.