Running Issue

[zacke22]

I have an 2002 Speed, mostly stock, except for boomer's intake, fmf pipe, updated crank, and locking bolts.

I was wondering if I could get some help from everyone on here. First of all, here's the main symptoms of my problem:

It starts and idles fine, but when the throttle is pushed, it spits and sputters (sounds like a cold polaris haha). Usually when it spits and sputters, it'll die unless i let off the throttle quickly, and every once in a while it will backfire through the intake.

Here's the list of possible causes I've already checked:

-Battery is fine
-I have spark
-Returning fuel flow into the tank is normal, and flowing at high pressure


If anyone could give me an idea on what I should check next, I would greatly appreciate it. I'm clueless to why this just now started happening, when all the bike has done is sit in the garage lately. It ran fine last time I got it out.

[wistech]

Sounds like a bad tps or one that has water penetration . Did you pressure wash it lately? It could be an injector that unplugged but generally they wont stay running by letting off the throttle. If it starts just like always that might also rule out a spun flywheel but its an easy check. Are your quick connects gutted and check the in tank fuel filter screen as well as replace the inline filter.

[zacke22]

QUOTE (Wistech @ Mar 31 2010, 11:26 AM) <{POST_SNAPBACK}>

Sounds like a bad tps or one that has water penetration . Did you pressure wash it lately? It could be an injector that unplugged but generally they wont stay running by letting off the throttle. If it starts just like always that might also rule out a spun flywheel but its an easy check. Are your quick connects gutted and check the in tank fuel filter screen as well as replace the inline filter.

Thanks Wistech,

Quick connects are gutted, I'll check the tank screen tonight, and replace the inline filter asap, along with checking the flywheel and injectors.

Also, I haven't powerwashed it lately, but the last time I rode it was several months ago, so maybe I messed something up last time i powerwashed it then and am just now finding out about it? What can be done to fix a bad tps or one that has water penetration?

[polyesterpig]

I had the same problem.

The fix,

I did not push the tps sensor connector all the way in. It was just resting on top.
It is located on the trottle body. Just push on the connector and make sure it snaps down.

Let us know what the fix is.

[zacke22]

Okay, well here's the update:

Things I've checked/done

Good Battery
Good Return Flow of Fuel
Replaced Inline Fuel Filter
Checked Tank Screen
Taken Throttle Body off, and primed system to check if both injectors were working, and they are.
Checked TPS connection/wires and everything is fine (don't know about actually TPS though)
Quick Connects are gutted (as previously mentioned)
Flywheel Key if fine

Thats everything I can think of...

None of these seemed to help anything. Like I said, it can sit there and idle all day...but shortly after i start giving it gas it starts cutting out, spits and sputters, sometimes dies, sometimes doesn't, and the occasionaly backfire. Sometimes it does okay for a second or two, up to the middle of the rpm range or so.

One thing I did notice though is that the inline filter starts to empty as I give it gas, and it seems as if the motor finally dies when you can't see anymore fuel in the filter. So, what should I do next? I guess I'm starting to assume my TPS needs recalibrated, and unfortuanely I don't have a dealer cal or D&M kit.

Any suggestions? Could I take the TPS apart and try to figure if there's a problem with it?

[Kuma]

See if you can hook up with someone with a D&M, that way you can eliminate the TPS and doing a throttle cal couldn't hurt either.

[cdale490]

QUOTE (Kuma @ Apr 2 2010, 06:20 AM) <{POST_SNAPBACK}>

See if you can hook up with someone with a D&M, that way you can eliminate the TPS and doing a throttle cal couldn't hurt either.

Unplug your stator and start your bike it will run off the battery then try reving the bike if this works you might have signal disruption and its an ez fix. I had this happen on 2 bikes I worked on, you just unplug the output from voltage reg going back into the main wire harness and wire direct to the battery this will give you a clean signal and your battery will still charge. I do this to all the bikes I work on if you need pics I can post some.

[claas900]

Also look at the relay under the air filter,sometimes they can do funny things. You can just remove it for testing purposes. See what it does then.

[cdaleman440]

Try running new fuel line from the rear tank connector to the pump. If you fuel line is soft the pump will suck it shut as it pulls fuel from the tank. I just went threw this with mine.

[peterock]

Put a meter on your tps. when you push the throttle it should gradually change, not jump around.