Haybusa Parts and Service Member Support
« previous next »
Pages: [1]   Go Down

Author Topic: WTF!!! Engine backfiring through throttlebodies!!!  (Read 4711 times)

Offline J.R.

  • Post Whore
  • ****
  • Posts: 800
  • Gender: Male
WTF!!! Engine backfiring through throttlebodies!!!
« on: February 28, 2010, 07:52:58 PM »
Rebuilt 1300 w/ JE pistons. Cams degreed at 107 Ex/In. Everything looks right mechanically. Updated ECU, rotor and harness to 05. I'm thinking I'm missing something in the sensors(vac. hose routed wrong) It acts like timing is 180 out. I'm going to sleep on it and leave it alone for a day. I'm sure it will come to me or one of you guys have run into this before. Engine spins but won't start. When you crack the throttle open it backfires through the throttlebody. It seems I ran into this before with someone else but can't remember what he found. Any help with this will be greatly appreciated. Thanks, Don.
Logged
The Wizard
Old dudes still can get it done!! Old age and treachery will overcome youth and enthusiasm every time!

Offline jblankenship

  • Rider
  • ***
  • Posts: 281
Re: WTF!!! Engine backfiring through throttlebodies!!!
« Reply #1 on: February 28, 2010, 09:16:37 PM »
stock cams? put the same ones back that were in there before?
Logged

Offline sportbikeryder

  • OFF TOPIC
  • Universal Post Whore
  • **********
  • Posts: 7352
  • Gender: Male
Re: WTF!!! Engine backfiring through throttlebodies!!!
« Reply #2 on: February 28, 2010, 09:19:22 PM »
What year was the bike? If an '01, upgrade is just drop in ecu and rotor. If 99-2000, you need to swap wires in the connector.
Logged
Any day on a motorcycle like this that ends just needing parts and labor is a good day.
4.82, 158.67mph 1/8th mile 7.350, 200.32mph 1/4 mile Riding

4.392, 176.79mph 1/8th mile  6.610, 228.15mph 1/4 mile Tuning

Offline J.R.

  • Post Whore
  • ****
  • Posts: 800
  • Gender: Male
Re: WTF!!! Engine backfiring through throttlebodies!!!
« Reply #3 on: March 01, 2010, 04:59:23 AM »
Quote from: jblankenship on February 28, 2010, 09:16:37 PM
stock cams? put the same ones back that were in there before?
Two intake mod.
Quote from: sportbikeryder on February 28, 2010, 09:19:22 PM
What year was the bike? If an '01, upgrade is just drop in ecu and rotor. If 99-2000, you need to swap wires in the connector.
All was working before teardown. Just swapped to newer harness. I just missed something ,Jon. Been house hunting with wife and too tired to think. :?
Logged
The Wizard
Old dudes still can get it done!! Old age and treachery will overcome youth and enthusiasm every time!

Offline sportbikeryder

  • OFF TOPIC
  • Universal Post Whore
  • **********
  • Posts: 7352
  • Gender: Male
Re: WTF!!! Engine backfiring through throttlebodies!!!
« Reply #4 on: March 01, 2010, 06:15:12 AM »
Maybe you swapped teh TPS and one of the pressure sensors. If I am not mistaken, I believe the connectors can inadvertantly be switched.
Logged
Any day on a motorcycle like this that ends just needing parts and labor is a good day.
4.82, 158.67mph 1/8th mile 7.350, 200.32mph 1/4 mile Riding

4.392, 176.79mph 1/8th mile  6.610, 228.15mph 1/4 mile Tuning

Offline Yngve

  • Post Master
  • *****
  • Posts: 1765
  • Gender: Male
Re: WTF!!! Engine backfiring through throttlebodies!!!
« Reply #5 on: March 01, 2010, 06:47:31 AM »
The vacuum-hose to the manifold pressure sensor is loose ( Intake Air Pressure Sensor ).
Reconnect it and it will be fine :)
Logged
I dont know what I am talking about but I do know that I am right :)

Offline J.R.

  • Post Whore
  • ****
  • Posts: 800
  • Gender: Male
Re: WTF!!! Engine backfiring through throttlebodies!!!
« Reply #6 on: March 01, 2010, 09:35:50 AM »
Quote from: Yngve on March 01, 2010, 06:47:31 AM
The vacuum-hose to the manifold pressure sensor is loose ( Intake Air Pressure Sensor ).
Reconnect it and it will be fine :)
Quote from: sportbikeryder on March 01, 2010, 06:15:12 AM
Maybe you swapped teh TPS and one of the pressure sensors. If I am not mistaken, I believe the connectors can inadvertantly be switched.
Will check on these later tonight. Thanks. :thumb:
Logged
The Wizard
Old dudes still can get it done!! Old age and treachery will overcome youth and enthusiasm every time!

Offline ira1031

  • Rider
  • ***
  • Posts: 95
Re: WTF!!! Engine backfiring through throttlebodies!!!
« Reply #7 on: March 18, 2010, 03:14:06 AM »
re check your cam timing , make sure spark plug wire's are in the right order , - an make sure there is no intake leak.
Logged

Offline J.R.

  • Post Whore
  • ****
  • Posts: 800
  • Gender: Male
Re: WTF!!! Engine backfiring through throttlebodies!!!
« Reply #8 on: March 18, 2010, 03:27:24 PM »
Quote from: ira1031 on March 18, 2010, 03:14:06 AM
re check your cam timing , make sure spark plug wire's are in the right order , - an make sure there is no intake leak.
Cam timing good, spark plug wires in the right place, no intake leak. What I've found is a jacked up harness. After further inspection I've found strange colored wires that do not correspond with wiring diagram. My guess is someone tried to re-pin several plugs and got lost with what they were doing. Stupid me ended up with the jacked-up harness. I located and bought another working harness and when i get time will install it and will report back.
Logged
The Wizard
Old dudes still can get it done!! Old age and treachery will overcome youth and enthusiasm every time!

Offline fungames43232

  • Rider
  • ***
  • Posts: 192
  • Gender: Male
Re: WTF!!! Engine backfiring through throttlebodies!!!
« Reply #9 on: May 02, 2010, 03:59:11 PM »
I have actually seen this.  The cams were 180 out on the one I saw.
Logged
If it's too fast you're old
Pages: [1]   Go Up
« previous next »