Hard to start, The first time

[Kinarfi]

My trooper has had problems starting for quite a while, like in the morning or first start of the day. Been doing some checks on O2 sensor, IAC, TPS, it just won't quite catch fire and run.

I thinking of trying a primer to richen things up a bit like I had on my plane, Search Results - 800-Airwolf Rotax Parts Online Store features Ultralight Parts and Accessories. . Anyone tried this yet? any thoughts?

Kinarfi

[Guest Lenny]

My trooper has had problems starting for quite a while, like in the morning or first start of the day. Been doing some checks on O2 sensor, IAC, TPS, it just won't quite catch fire and run.

I thinking of trying a primer to richen things up a bit like I had on my plane, Search Results - 800-Airwolf Rotax Parts Online Store features Ultralight Parts and Accessories. . Anyone tried this yet? any thoughts?

Kinarfi

Keep in mind that on a fuel injected engine you would have to spray extra fuel into the intake. Just closing off the intake would not do it like on a carburator. Take your air filter off and use a spray bottle to spray gas in when cranking to try it. When putting my engine back to gether I went back to my stock injectors just to find one was plugged. Makes me think, pull your injector rail off by removing the 2 bolts holding it and pull it out. Clips on the rail will hold the injectors to the rail. twist it so the injectors will squirt across and above the engine head and give it a quick crank. You should see the injectors each fire out a spray of fuel one at a time. Look for fairly the same spray from all of them. It's easy to tell if one is not working good. It's real safe if you don't have open sparks anywhere but have a fire extingusher handy just the same and put a plastic barrier under the injectors so fuel can't run down the engine side but retain it all above everything. Keep in mind that a cold engine doesn't evaporate the fuel as quickly so a poorly spraying injector could be a problem when things are cold but still be OK when things warm up.

Lenny

[Kinarfi]

Keep in mind that on a fuel injected engine you would have to spray extra fuel into the intake. Just closing off the intake would not do it like on a carburator. Take your air filter off and use a spray bottle to spray gas in when cranking to try it. When putting my engine back to gether I went back to my stock injectors just to find one was plugged. Makes me think, pull your injector rail off by removing the 2 bolts holding it and pull it out. Clips on the rail will hold the injectors to the rail. twist it so the injectors will squirt across and above the engine head and give it a quick crank. You should see the injectors each fire out a spray of fuel one at a time. Look for fairly the same spray from all of them. It's easy to tell if one is not working good. It's real safe if you don't have open sparks anywhere but have a fire extingusher handy just the same and put a plastic barrier under the injectors so fuel can't run down the engine side but retain it all above everything. Keep in mind that a cold engine doesn't evaporate the fuel as quickly so a poorly spraying injector could be a problem when things are cold but still be OK when things warm up.

Lenny

Your last sentence seems to be right on, so if I get an injector and put it where that black plug is on manifold body and hook it to a push button, I would have a dandy primer that sprays. The one mentioned earlier is just a small hand pump and I don't know if it sprays or just dumps raw fuel into the manifold.

[BeeZee62]

Your last sentence seems to be right on, so if I get an injector and put it where that black plug is on manifold body and hook it to a push button, I would have a dandy primer that sprays. The one mentioned earlier is just a small hand pump and I don't know if it sprays or just dumps raw fuel into the manifold.

I've been following all the discussions on hard starts and am very thankful that I've not had that problem. However, every other tank of gas I've been adding a bit of injector cleaner and I'm wondering if all the problems being experienced could just be dirty injectors? I'm not all that mechanically inclined and quite frankly most of the mechanical discussions on here are well above me - but most valuable as I'm learning a lot, and I'm not meaning to insult anyone's intelligence - but sometimes the obvious has to be asked.

Barry

[Kinarfi]

I've been following all the discussions on hard starts and am very thankful that I've not had that problem. However, every other tank of gas I've been adding a bit of injector cleaner and I'm wondering if all the problems being experienced could just be dirty injectors? I'm not all that mechanically inclined and quite frankly most of the mechanical discussions on here are well above me - but most valuable as I'm learning a lot, and I'm not meaning to insult anyone's intelligence - but sometimes the obvious has to be asked.

Barry

Not the least bit insulting and I thank you for your question and will do just exactly that and see if things clear up.

The only bad question in my book is the one that doesn't get asked.

Thanks Barry,

Kinarfi

PS, I messed with my pressure regulator the other day and because it is dead ended, I flushed the connection just in case, I think a small orficed return to tank port would be good so any thing that get in the line after the filter have a way out other than through an injector.

[Guest Lenny]

Your last sentence seems to be right on, so if I get an injector and put it where that black plug is on manifold body and hook it to a push button, I would have a dandy primer that sprays. The one mentioned earlier is just a small hand pump and I don't know if it sprays or just dumps raw fuel into the manifold.

Keep in mind that most injectors have a duty cycle, You might want to check on Google to see how long you can hold that button on without burning out the injector. Probably not a problem but check anyway.

Lenny

[rocmoc]

Even if you had a plugged injector, it should TRY to start and run. Will not be smooth but it will still run. IF you are getting fuel, I would be surprised if it is the injectors themselves. Sensors & circuitry more likely. Injectors are more reliable than a carb IMHO!

Joyner Dealers, any ideas?

rocmoc n AZ/Mexico

[Kinarfi]

Have a seat and I'll tell you an analytical story. I have had problems getting the trooper to start. Lenny said pull the injectors and see if they spray proper, I did, & they did. So then I tried dumping some gas down the air intake any attempts to fire up were gone, hmmmm, richer and less signs of life, next I increased the pressure of the regulator, and again, no indications of it coming to life, so I floored it and got a few signs that it wanted to run, but only for a moment, and then the moment was gone. hmmmmmm, too rich, about right, probably lean. Backed the pressure off to a little less than 30 psi and I got is started, kept it running and got it warm and worked on a few things and drove it some. Tomorrow, I'll try again and see if that helped. Got to think also about my messing with the IAC, when it operated, it would drive in, then drive out, So I'm thinking, at start up, the IAC drives in until it can't drive any further, backs off a preset amount and assumes that a certain amount of gas will get injected and thus have the correct mixture and run. Too much pressure, too much gas, so instead of adjusting the air, you adjust the fuel via the pressure. That is, the computer sets the air via the IAC, is preset to allow just so much gas in via injector timing, thus the need for proper pressure. Maybe altitude effects (edit) what the fuel pressure should be set at.

Kinarfi

[Guest Lenny]

Have a seat and I'll tell you an analytical story. I have had problems getting the trooper to start. Lenny said pull the injectors and see if they spray proper, I did, & they did. So then I tried dumping some gas down the air intake any attempts to fire up were gone, hmmmm, richer and less signs of life, next I increased the pressure of the regulator, and again, no indications of it coming to life, so I floored it and got a few signs that it wanted to run, but only for a moment, and then the moment was gone. hmmmmmm, too rich, about right, probably lean. Backed the pressure off to a little less than 30 psi and I got is started, kept it running and got it warm and worked on a few things and drove it some. Tomorrow, I'll try again and see if that helped. Got to think also about my messing with the IAC, when it operated, it would drive in, then drive out, So I'm thinking, at start up, the IAC drives in until it can't drive any further, backs off a preset amount and assumes that a certain amount of gas will get injected and thus have the correct mixture and run. Too much pressure, too much gas, so instead of adjusting the air, you adjust the fuel via the pressure. That is, the computer sets the air via the IAC, is preset to allow just so much gas in via injector timing, thus the need for proper pressure. (Original has an edit). Maybe altitude effects fuel pressure.

Kinarfi

Altitude will effect fuel pressure but not enough to be a consideration. The computer looks at the MAP (manifold absolute pressure) sensor, which is mounted on the side of the aluminum intake manifold, to determine how to adjust for elevation. Rocmoc is right that it will run with a bad injector. It will be rough and will start a little harder. If there are other issues, a bad injector could put it over the edge so it won't start at all. Remember injectors can just quit but it is more common for them to gradually become plugged and the quality of the spray gradually lessens. The poorer the spray, the poorer the preformance.

Lenny