[LPG2CV]

That is certainly not going to help to get the idle down.

Without knowing the mechanism, it obviously suggests an issue with bank to bank adjustment. (unless a cam is out a tooth!)

It would be intersting to know how the manual says to approach balancing.

[Rednaxs60]

Cylinder Balancing:

Cylinder Balancing.jpeg (186.66 KiB) Viewed 1885 times

[LPG2CV]

You want to run through efforts you have made to fix this issue?

Perhaps the hive can come up with ideas

[Rednaxs60]

Been through all troubleshooting and setting ideas from Honda. Have also read in the Supplement manual regarding timing in that you time for #1/2 (wasted spark - viewing hole s on the left cylinder bank side - #2/4) and the flywheel mark is what is used - knew this. Read further because never time with any cylinder but #1/2. Since timing is confirmed using #1/2, further confirmation can be done using #3/4 cylinders. there is a second mark on the flywheel for this confirmation. Lastly, was reading the Squirt manual for information sake and found a section that referred to the dual cam sensor arrangement on these early FI systems. Mentions that this is to enable wasted spark on these engines. Brings to mind that the cam sensors are for wasted spark and the crank trigger wheel is for cylinder orientation. Which ever way this is more information than I had before. The other bit of info gleaned from my reading/browsing is that Hall Effect sensors work well with single tooth and half moon single tooth trigger wheels.

Cylinder Timing.jpeg (130.01 KiB) Viewed 1858 times

[LPG2CV]

I think your way forward, is the 36-1 wheel. you need to forget OEM, and think Speedy

The cylinder bank balance is what concerns me, as I think that may be the issue restricting you getting the rpm down at idle.

[Rednaxs60]

I am thinking Speedy, but there are some issues that are interconnected. Setup of vacuum hose(s), igniters and the OEM coils - it was mentioned that electronic components such as spark igniters can have a best before date. Will continue with the 36-1 wheel for the present.

The cylinder bank balance with the cylinder bank balance screw has been mistaken for the idle adjustment screw. Many make the mistake and confuse the idle screw with the cylinder bank balance screw. The cylinder bank balance screw adjusts the throttle plate opening. Will check as I mentioned.

[JHolland]

If it pulls cleanly under load then the spark will be more than enough at idle so I don't think that is an issue.

[Rednaxs60]

Progressing the project from a read standpoint. Lots of good info that I am reading that clarifies what you good people have been saying. Always makes more sense after a few times.

Checked the throttle plates yesterday. Took off numbers 3/4 injector holders and checked the throttle plates for movement. Idle adjusting screw unscrewed to full in is about a mm of movement. Not a huge difference in throttle plate opening. The IAC system opening provide the majority of air for idle and coasting while riding. Having seen this, it makes sense why the engine is operating a bit rich on start with the OEM system (no adjustment for fuel/air mixture). Don't require a great amount of fuel for idle or coasting:

IAC Opening .JPG (105.75 KiB) Viewed 1719 times

The new VE table I'll be working with has better numbers in the 40 percent range. Adjusting the idle for too high a percentage will not achieve the aim. New VE table values:

VE Table - New.jpg (79.43 KiB) Viewed 1719 times

Setting up the coils today. Good riding weather today, ride on the Spyder is in order.

Have mentioned the vacuum system and what can be done. Thinking I'll start by using #1 cylinder vacuum for the MAP sensor, plug all the other vacuum ports related to the MAP system - can change to a different cylinder if necessary to find which one is optimal for the tuning. Thinking that the use of the four cylinders for MAP vacuum was keeping the MAP reading higher than it should be - has been reading in the 60/80 percent range instead of in the 30/40 percent range. Difference in tuning I'd suspect.

For my acronym list - VAG coils. Does VAG mean Volkswagen-Audi-Golf ? Just wondering.

[LPG2CV]

Yes, correct regarding VAG

Just taking the MAP from one TB, is not so good as from Four. Four, with a smothing chamber in the middle, is better still.

Using 1 TB means you will get wild differences in MAP pressure as the engine goes from stroke to stroke. With the shared system, there is always one cylinder on the inlet stroke.

Regarding the 1mm of throttle plate opening. that is a vast amount of air difference. The first part of the throttle plate opening, is larger than any other. As the plate opens further and further, the difference per mm gets smaller and smaller per volume of air. It's because of the arc of the plate.

No one TB MAP should be any different from another. If it is, you need to resolve that.

Your first goal should be all cylinders having the same MAP reading at idle. when that is achieved, tuning will be easier.

[Rednaxs60]

Acronyms abound no matter what the forum, organization. Lots from my navy days.

Gpineau tried this with his Kawasaki EFI conversion, he had better results from using one vacuum port. Have a mixing/smoothing chamber, just need a spot to install it.

The 1 mm movement didn't appear to open the throttle plate significantly. No information available regarding the throttle plate setting in any of my service manuals.

Looking for a second air chamber so that I can compare differences, and use as a possible test piece for issues such as this. These are not inexpensive.