Haynes Forums  

Go Back   Haynes Forums > Haynes Roadster Forums > Engine/transmission
FAQ Members List Calendar Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Display Modes
  #1  
Old 7th May 2015, 08:02 PM
onedayTM onedayTM is offline
Senior Member
 
Join Date: Jun 2007
Location: Tamworth, Staffordshire.
Posts: 207
Default megajolt and bike carbs?

I have 1.8 zetec with bikes which does not have TPS, what do I need to get it going. Is it just trigger wheel and flywheel sensor, or do i need TPS and just cranks sensor. My megajolt does not have vacuum point.
any help welcome.
cheers tony
Reply With Quote
  #2  
Old 7th May 2015, 08:17 PM
davedew's Avatar
davedew davedew is offline
Senior Member
 
Join Date: Jul 2010
Location: Taunton
Posts: 342
Default

You can get the engine to run using crankshaft position sensor and EDIS 4 on its own.
You will need EDIS as Megajolt cannot drive the coilpack directly.
If you want a full 3d ignition setup you will have to add a TPS to the carbs.
Triggerwheels sell TPS sensors.

HTH
__________________
http://s831.photobucket.com/user/dav...ter%20Pictures

OTR 01/05/14 - 1.6 CVH, Type 9, Bike Carbs, Megajolt
Reply With Quote
  #3  
Old 7th May 2015, 08:52 PM
onedayTM onedayTM is offline
Senior Member
 
Join Date: Jun 2007
Location: Tamworth, Staffordshire.
Posts: 207
Default

ok cheers david
Reply With Quote
  #4  
Old 7th May 2015, 09:23 PM
Tatey's Avatar
Tatey Tatey is offline
Senior Member
 
Join Date: May 2009
Location: Leicester
Posts: 827
Default

I'm running a 1.8 silvertop zetec with ZX6R carbs (no tps) and megajolt. As Dave says you just need a coil pack, use the crank position sensor and EDIS 4 unit. I am using a MAP sensor with my engine due to the lack of TPS on my carbs. I have just drilled and tapped my inlet manifold with an M3 tap and then fitted some welding tips drilled out to 2mm which are also loctited in place to make them air tight to the manifold. I've then teed the 4 vacuum feeds together and then they go into one of the plastic fuel filter housings which acts as a damping unit to smooth out the vacuum signal. This is then attached to Megajolt.

Using a MAP sensor has a few advantages over TPS in that it more accurately shows how the engine is breathing as TPS doesn't show load, only throttle opening. However MAP can be more of a faff to get a smooth signal from.
__________________
1.8 Silvertop Zetec (ZX6R Carbs + Megajolt) + Type 9

My Build Blog: http://www.haynes.co.uk/forums/showthread.php?t=2736 - Last Update: 31st October 2020

Total Spent so far: Stopped counting
Reply With Quote
  #5  
Old 7th May 2015, 09:32 PM
onedayTM onedayTM is offline
Senior Member
 
Join Date: Jun 2007
Location: Tamworth, Staffordshire.
Posts: 207
Default

Yes i was hoping to do that but there is no connection on the back of my megajolt, it's one I bought of someone who was selling up and I see on the box it is from 2008. Looks like I will be fitting TPS.
cheers tony
Reply With Quote
  #6  
Old 7th May 2015, 10:34 PM
wylliezx9r wylliezx9r is offline
Senior Member
 
Join Date: May 2010
Location: South Wales
Posts: 321
Default

You'll also find that you get better throttle response using TPS rather than MAP. MAP is only really neccesary for charged cars and emmission control.
Reply With Quote
  #7  
Old 26th June 2015, 10:38 PM
baz-r baz-r is offline
Senior Member
 
Join Date: Nov 2009
Posts: 1,464
Default

Quote:
Originally Posted by wylliezx9r View Post
You'll also find that you get better throttle response using TPS rather than MAP. MAP is only really neccesary for charged cars and emmission control.
i dont realy agree as its really more of an engine dependent factor rather than rule of thumb

both tps (alpha-numeric) and map (%baro) have there limitations for mesureing engine load

tps is poor at mesuring load as its has no way of knowing what load is on the engine (eg cruse and overun) and poor scaling for small tps movements away from idle so its useless for road driving

map works well unless you either have poor vacum at idle eg 65kpa or higher (wild cams with lots of valve overlap in 8v engines) and is not too acurate past 90% atmosperic pressure

for ignition only setups like megajolt you only need to work out engine load for added part load ign advance! so all we need to know is how full a cyl is and inlet pressure is the best way to do this and easy to set up as past 80-100% baro you need no extra advance.

people rattle on about tps to be used for bike carbs but its rubbish and most carbs off bikes are cv type so tps is not a true mesurment as carb slides control actual inlet aperture size! for what ists worth you may as well be 2d and have fixed advance for revs.

its not like we have to calcualte anything for fueling unless we have a turbo then we would have to take out advance under boost
Reply With Quote
  #8  
Old 28th June 2015, 08:07 AM
snapper snapper is offline
Senior Member
 
Join Date: May 2007
Location: Chelmsford, Essex
Posts: 360
Default

The above reply is good
If you have carbs without TPS and Megajolt without MAP your options are .. buy a set of carbs with TPS or rig a bracket to take TPS if you have enough throttle shaft to work with.
You can't bodge a TPS jolt to run without an input, you could rig the TPS to throttle cable or pedal, bit of a faff.
Earlier a reply said you can run the car without Megajolt just using EDIS, you can but will have a fix 10 degrees throughout the Rev range
Reply With Quote
  #9  
Old 28th June 2015, 02:15 PM
norton norton is offline
Senior Member
 
Join Date: May 2015
Posts: 434
Default

If you run them from one air box and a cone filter you could use a large dia' hotwire sensor?
Reply With Quote
Reply


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT +1. The time now is 12:54 PM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.