Magnelli Injection hard start

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Oct 19, 2009 | 03:05 PM

#11

2000FiveOh

Tourer

Joined: May 2009

Posts: 315

Likes: 1

Quote:

Originally Posted by eddfive

Here is the proper procedure: http://www.harley-heaven.com/M1105_idle_speed_MM.pdf
What they do not tell you in the bulletin is you need a sniffer probe to make sure the Fuel values are correct at cold start and idle. They also do not mention about the TPS adjustment which may need to be done if the voltages are too high. The 1105 bulletin needs to be followed exactly to have success, no short cuts. This is basically setting up the closed throttle position or idle position of the TB/TPS and the entire fuel curve is based on this adjustment. If you randomnly move the hot idle up/down you have just reset the zero or idle TPS value so it shifts the entire curve. The bike may run okay and it may not. This is why to do this procedure correctly you really need a dyno, sniffer probe, and diagnostics capability to adjust voltages and fuel curves in the ECM. This is why when you do motor upgrades to an M&M the stock settings in the ECU for cranking fuel and timing may be off. Putting on an addon fuel device can not help cranking fuel or starting. I have also noticed that M&M TB parts are getting harder and harder to find. It is also getting harder and harder to find techs that can work on or adjust this throttle body.

Changing the hot idle speed screw isn't going to throw off the fuel curve in the ECM. The ECM doesn't know if you have your hand on the throttle holding a certain rpm or if it's sitting on the stop with no hand touching the throttle. How will the ECM know if I'm physically holding the rpm's at 1000 rpm's or the rpm's are being held there by the throttle stop? It won't. What throws the fuel curve off is a bad TPS setting. The TPS needs to be set with the screws backed all the way out so the blades are totally closed, not slightly open at idle. Once that inital TPS setting is good to go then the bulletin procedures can be followed. You don't need a sniffer to set up correct warm and cold idle "speeds".

It would be nice to have a sniffer to set up the idle "richness", but that can be done by ear and feel if someone really knows their bike. Having the "richness" screws set correctly makes a huge difference in how the engine idles, ie: smooth or trying to jump off the frame. The rpm's can be set up correctly but if the richness and sync between the front and rear cylinders (screws hidden under the silicone) are out of whack, the bike will idle at the correct rpm, but shake like a sob.

But, you're correct that the bulletin leaves out many important steps and situations if one wants to tune the old systems. There's more to it than adjusting the warm/cold rpm's. There really isn't much published to help someone learn how to set these up and that's probably a big factor in why it's difficult to find someone that can do it correctly or even willing to screw with them.

Oct 19, 2009 | 03:33 PM

#12

binkley2

Thread Starter

Intermediate

Joined: Oct 2009

Posts: 47

Likes: 0

From: Central Texas

I think I amfollowing all this. So basically my dealer did not really know what tod with it, and adjusted my dile screws to mask the underlying problem. I will try the multi cycling of the fuel pump as soon as I get back home. I had absolutrey no problems with the start up until the stage 1 "upgrade". I have another indie in my area that many of my friends have used to dyno tune their bikes, perhaps I will go see if he has experince with the Magnelli. Thanks everyone for your help. Dennis