I am fairly new to this forum and you have probablyt heard this complaint before, but here it comes again! I have a 2000 Ultra Calssic FLHTCUI with the old style Magnelli Injection. I have done the Stage one download and air cleaner form HD, Have Samson trduals with baffled long fishtails. Top end rebuild last year with Keith Black 11:1, and new stock cams, 30 over bore. The bike has always been hard to start. I have to crank 4-5 times to get it to rattle. Even after long ride, if it sits for more than 15 minutes. I have added a Cobra injection tuner which fixed a lot of my rideability problems but did not fix hard start. I really do not wnat to go to a carb, which is what my indie has sggested. Bike rides and truns great, pleanty of power, but the comments about giving me a push to get it started are getting old. Does anyone have any suggestions? Please?

 

3 things your bike needs to start or run are: Fuel, Spark and Compression. Let's eliminate spark, since the bike runs good once cranked. That leaves the other 2. Unfortunately, the early MM EFI had some shortcomings that affected performance, not just on strock bikes but particularly on modified motors. Some of the probledms reported were hard starting, erratic idle and tuning difficulty. For performanced motors, the dual-plenum throttle body with independent runners feeding each cycliner, was too small to pass required air into the engine. Another major short coming was the flawed placement of the intake ari temp., sensor within the throttle body. All that being said, let's do a compression test. This is done dry ( without squirting oil in the cylinder) You need at least 80psi for combustion to occur. Less than 115 will caused starting problems. 120 to 150 is good for stock bikes.
150 to 165 for heavily modified bikes. 165 to 180 will also cause starting problems, spark knock and overheating. If compression check out, then let's go to fuel pressure. You will need a fuel pressure guage to connect into the supply fitting at the tank. Your dealer or Indy should have these. With the engine idling use a vacuum pump to apply 12-14 inches of vacuum to the atmospheric pressure port of the fuel pressure regulator. Fuel pressure should drop as Vacuum is applied. Does it ? No, faulty regulator or port plugged. Yes, then fuel pressure should remain steady at 40-47 psi with the vacuum removed and the engine reved up. If all this checks out, I would not go to a carb. Zippers performance has the answer for $1,849.00 (ouch) But, it will cure all of the problems associated with the MM system. It's called the ThunderMax EFI Conversion Kit. You might want to check this out.

Stroker

 

You need to find someone who can tune and program the M&M ECU. If everything mechanically is sound it boils down to the Throttle body being set up correctly and cranking fuel table in the software. If it does not idle up to 1300-1500rpm on start and idle faster when cold until warm, 224degreesF, and then settle in on an idle of 950-1050rpm then the TB needs to be set back up. On an M&M if you move the idle blades too much it throws the entire fuel curve off so the bike would need to be tuned correctly to the new throttle settings. Stage one download does absolutely nothing for True Dual exhaust so it should have been set up and tuned when you did all of your upgrades. No add on fuel device will help start up, requires the Cranking fuel table to be adjusted. Once you get this done it will start and run like it is supposed to.

 

Holy cow. I have hit the holy grail of information! I will look at all of your suggestions and let you know what I find out. I will say, the bike started fine until I put the exhaust and the Stage 1 (both done at the same time by the Dealer) at that time bike ran like crap and started hard. Took bike back and they adjusted cold and hot idle which helped but still hard start. Indie did rebuild about 5 months later and added Cobra controller. Much better performance but still hard start. Wife's Deluxe starts on first punch (bone *** stock) which is something of an embarrassment. I live in Texas for gods sake starting should be no problem! Thank you for the suggestions, I will not waste them.

 

I think Zippers makes a conversion kit for the MM EFI system. If you can't get it to run right you may want to investigate that. I would not go to a carb setup.

look here: http://www.thunder-max.com/Products/...arelliKit.aspx

 

If the dealer adjusted the cold/hot idle then I suspect your fuel curve and TB are not setup properly. Moving the hot idle adjustment throws the entire fuel curve out of whack. The cranking fuel table requires a tuning device that will reflash the M&M ECU and a re-tune the fuel table of the ECU. No add on device will work for cranking fuel.

 

Try cleaning the throttle body with brake or carb cleaner. Put the nozzle of the spray can into the two holes at the top of the body bores and clean them thoroughly. Those are the idle air bleed holes and if the get gummed up bike doesn't get enough air to start properly.

Does the idle air control stepper motor work?

 

You mention the throttle body being set up correctly. Can you provide a detailed and specific procedure for the set up. I'm assuming you know how to set up the throttle body if you mentioned it in your post. I'm curious what info you have concerning the set up.

 

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.

 

As previously mentioned by Stroker1948, you need to buy or borrow a HD fuel pressure adaptor w/guage, the most important tool in the tool box for trouble shooting fuel injection.

There are many things, as previously stated here, that can cause hard starting. Another cause that you may want to check is how long you have residual fuel pressure after you turn the engine off hot or cold, should retain pressure for 20 minutes or more both ways. It should hold your normal fuel pressure of approx 42 psi for several minutes and gradually decrease to zero over a long period of time, for some fuel systems this takes several hours. But within 20 minutes it should still stay close to the normal pressure. If it does not you have a defective check valve within your fuel pump or a defective fuel pressure regulator or a leaking injector or the high pressure hose or a hose connection is leaking within your tank. If you find that you have a problem retaining pressure there are further diagnostic routines such as clamping shut one of the two external fuel hoses at a time, which we wont get into at this time.

Residual pressure is very important on EFI engines for this reason, when you turn your hot engine off the fuel is also hot in due to the hot intake manifold that contains fuel for the regulator and injectors. If this fuel were to lose pressure too quick it will boil and create air pockets that later would cause long cranking conditions until this air is purged back out (your injectors are blowing bubbles). If the loss of residual pressure was caused by a leaky injector, you would initially have a starting problem due to an engine flooded condition.

One way to test as to if this is the problem, before you try to start your engine, turn on your ignition and let your fuel pump run for its approx 4 sec prime cycle, turn ignition back off and wait for 15-20 sec, then repeat this sequence a few times. This preceedure helps to purge this trapped air out of the intake manifold and back into the tank thru the return line, if the bike starts easier now then you probably a residual fuel pressure problem. This test is not 100% effective but if it does change your starting condition, it is trying to tell you something.

Good luck