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Why do you think the engine is not happy on throttle lifts? It sounds lean and that's good, the throttles are closed after all...

That's what race cars sound like. Street cars have things to keep the throttle open a bit while decelerating, but that's for pollution regs.

When you get more practice it will pop less because you'll spend less time slowing down and more time going faster

Well the engine isn't really very happy anywhere,just more noticable with all the popping going on.It's a bear to get running cold(like start and quit 20 times at least),it runs really rough while its warming up and less rough when up to temp,its not pulling on the top end like it should either.When I 1st got it running it started cold like it should and ran as smooth as silk,that slowly changed into the above problems.I can't find any reason for the changing with either the fuel or ignition systems,no fault codes are showing to give clues.
If you watch the 1st video I posted at the kart track you can clearly hear the difference and see that the car is pulling harder.

Sigh. Sounds like it's lean everywhere. If you aren't using stock airbox and exhaust that would likely lean it out. THe popping is ok, the other stuff can take a toll on the engine.

The weather is colder now. Does it start better with your hand or arm over the, oh wait that's injected isn't it? One less fun thing to do. I remember watching a guy trying to start an old F1 car that showed up one day for time trials. He was drapped all over the rear end of the car using a squirt oil can full of gas on the 8 intakes to keep it firing. He clearly thought the car was female . The sound the car made was so horrifying from 30 feet away that my girlfriend went slack jawed and was unable to move her feet, despite her very obvious desire to be absolutely anywhere else in the world... It was kinda hilarious, but I was enjoying it too much.

So try squirting gas in the intakes while it warms up. You'll look pro. Then try to think of something that might make it run lean or maybe a little restriction on the intake or exhaust, just for debugging? Maybe an extension on the inlet or an elbow on the exhaust - just a little change.

Sounds like you'll need to do as you say, get a programmable unit... Looks like your off to a good or fast start though!

The part that confuses me as that if you let it idle for a bit and give it a throttle stab it gives a dose of black smoke so its rich then but nowhere else.I've mucked with the cold start enrichment bar(you can manually slide it,normally controlled by an solenoid) and it makes little difference what you do with it,depending on how warm the engine is of course.
I have a set of R1 carbs from a previous project and was really tempted to install those,I'd have to rewire the thing all over plus the fi head boots are shorter so spacers need to be fabbed to get the carbs too fit.Might as well megasquirt it and take it from there,at least every aspect of the tune can be manipulated and once I add boost I'll have a system in place to tune with.

Have you done any plug reads? (take the car to full throttle - stab the clutch and hit the kill switch at the same time and coast to a stop with the clutch pressed in) It should give you a decent idea what the engine is doing under load.

For some reason bike engines also seem really sensitive to old plugs. Its probably around $60 but it might be worth picking up a new set and seeing if that helps the starting issue. Then again if the mixture is really off, it might just ruin them.

The plugs are scary white under load,and yes I did try new plugs 1st.I know I can add fuel with a piggyback and the stock system-if I could find out why it runs like crap it would be worth it.I'm not going to waste any more time chasing the stock set-up for faults,starting from scratch building the harness will be far better than the rats nest the oem harness became to use in a car.

Maybe your getting some oil down your valve guides. It builds up under high manifold vacuum at idle. Don't keep running it till you get something to fix it or at least try... Good luck.

No I don't think its burning oil at all,I've lots of worn out crap so I'm up to speed on the effects of that.

Little update I guess,the engine is running well on megasquirt and seems quite happy.I ran my 1st autox of the year today and set FTD about 2 seconds clear.I have some very big wings cut from foam and ready to cover in glass,I'll get pictures of those suckers once they're mounted.

Ran event #3 today,secured FTD by about 2 seconds on a 36.9 second course.

Vid #1 is on dot r-comps and #2 is on hooisers.

http://youtu.be/G7qjeyEt1lM

http://youtu.be/8r8nhAWhCgs

That is pretty nuts! Quite a rush, even watching it on video. Thanks for posting!

What is that sound that you hear throughout the video. It sounds metal on metal?

I have no idea what the camera is picking up,when I watched it the 1st time last night I was trying to think if what the hell that was.No abnormal noises heard while driving it and no comments by spectators,it sounds loud enough on the camera that I or someone without a helmet on should hear it.I have a feeling its panel vibrating but not sure.

That's great, FTD by 2 seconds - I think that means we get to count this as another successful build!


Now for some real track time...

Yes so far its been good,4 events and 4 FTD's ranging from 2 seconds to a little over 3 seconds.I'm purposely avoiding the track just yet,I want to make sure things seem good before I start cranking over 100mph and have a suspension failure or something.