got all the mega squirt wired in and running, the only problem is when warm it wont tick over any less than 1100 rpm. i have a 1600 cvh piper t2 cam ported head with bigger valves and low comp pistons (oh and using cossie4x4 blue injectors). so would expect to raise tickover a little from the stock 850-900, this just seems little excessive.

when i drop the ve table it just cuts out, if i drop the pulse width it cuts out. idle control is on warmup only and i`ve tried adjusting the tick over screw on my cossie throttle body unplugging the idle valve everything.

any ideas? is that a normal tick over for cvh engines with these mods?

 

air leak?

 

none I can find. could it be the difference in size of throttle body?

 

No.. most likely an air leak.. you need to set your mechanical base idle before you can do control it properly in software.

 

that's what I been trying dude. once it's warm the idle valve is switched off is that right? so once up to temp it's basically throttle valve and tick over screw. I thought maybe with the circumferance of valve being larger maybe it allows more air in. I'll double check for an air leak though. do ya know the usual idle speed of a cvh with same mods, my previous rst's have just been chipped or will they not make much difference? thanks.

 

What AFR and spark angle are you running at warm idle?

 

using edis for spark, 10 deg btdc, isn't it. my lc1 and megatune showing around 14.7 give or take few decimals.

 

Spray some carb cleaner or something around the TB and intake and see if the engine speed picks up.. if it does, you have a leak!

 

the FRST engine is meant to be 1.5% co at idle, which is an AFR of 13.9 or so. That might be worth a try. I got mine to idle below 1000 by upping the advance at 500rpm.

http://www.perfectpower.com/Technical_info/afr.asp

Have you got the car driving? I've still not had a chance to get mine driving since moving south.

JAmes.

 

I'll check it out again tomorrow mate.

 

na mate been trying to sort this idle out before I start tuning. gotta tidy few things up under the dash to. trying to make time to get in the garage is the other big issue. kids+mrs+project car don't add up slot of the time. LOL.

 

right then turns out there was indeed an air leak from one of my vaccum pipe unions, doh,missed that one.lol. got the idle down to 850 but it is hunting a fair bit. ego control is off till over 2000 rpm engine was held around 80-85deg, after start enrichment is off. vacum showing 50-55kpa, had a bash at dropping the fuelin on the ve table but seemed not to affect it much. afr reading around 12.5 so is a little rich. has anyone a tried and tested way of setting up the ve table around idle, when i put the generator figures in for the rough jobbie it starts a 700 and the step increment is 1200, surely i can use the 850 then go up in my own steps??

 

It'll run fast if it's that rich.. it'll slow down when you lean it off.. it should idle around 14:1 no problems and then you set your idle with the spark angle. 50 kpa still sounds like you have an air leak unless you're runny a laery cam.

 

running a piper t2 cam, dont get what you mean abuout setting the idle with the spark angle? im using edis 4 for my spark.