FiTech starting issues - what to adjust?

[Ihavea73]

Have a new blueprint 306 with Fitech 400. It runs great once I can get it started.

Prime shot setting was at 257 and for the most part it would fire right up when cold, but then was very hard to get it restarted when warm.

I turned down the prime shot setting to 200 and it seems to have made the warm starts only slightly better, but now cold starts take awhile. It cranks fine and you can hear it start to fire but then it dies. Eventually after cranking and cranking and trying anything I can with the throttle, it starts. I haven’t been able to determine a pattern for what makes it start.

Current settings
Prime shot - 200
Crank fuel 20f- 71.9
Crank fuel 65f - 29.7
Crank fuel 170f - 19.5
Crank IAC - 75.8
After start all set to 0

Can anyone advise what I need to adjust?
Thanks in advance.

 

[JB Fab]

Get it good and hot, shut off the the engine and look down the throttle body for fuel leaking past an injector...
Do you have a fuel pressure gauge in the engine compartment?

 

[Ihavea73]

I do not have a gauge.

I’ll look for a leaking injector. I did have to replace one of them when I first bought the vehicle as it just wasn’t working at all.

 

[.94 OR]

I have to make sure I let my pump prime for 6-8 seconds before I can get a good clean start. If I jump the gun and try to start too early it fights me since it doesn't quite have enough fuel. I don't have current settings in front of me. I did plumb a gauge into mine though.

 

[Ihavea73]

6-8 seconds whether cold or hot?

I’ll try running the prime shot multiple times and see if that helps, then get it good and warm to look for leaking injectors.

 

[.94 OR]

Cold. I just ran mine over to a local car show. Temp was showing 200°F so it was plenty warm. Bump the key and it starts.

 

[Ihavea73]

Alright, it even struggled with the "cold" start today (it is 88 right now). Did 2 prime shots, held the key and it fired a couple of times and died. Eventually I got it started. Voltage didn't drop below 10.5 on the handheld unit during cranking.

Got it warmed up, did not see any injector leaking when I got home. Shut it off. Let it sit for a couple of minutes and it fired right back up. BTW, with this 306, the warmest I have seen it get is around 180. When driving it runs about 160.

I'm going to try again in maybe half an hour, and it will likely be hard to start.

 

[Ihavea73]

I did 4 prime shots and it cranked a few times and fired right up.

Also, I have been watching some videos and they all say the IAC should be between 3-10 when idling. Mine is reading about 35. So I need to figure out which screw to adjust that.

 

[DirtDonk]

I would turn the prime shot back up to where it worked better for cold starts. Maybe even a little higher just to play with. Or even somewhere in between. Since it’s adjustable, it’s worth playing with.

When you’re cranking the starter, do you ever push on the throttle to change the blade position? I know the IAC is supposed to help with that and you theoretically shouldn’t have to do anything to the throttle at start up with fuel injection. Just wondering if in this case, it will help with the warm starts.

 

[Ihavea73]

Yes, I've pushed on the throttle and at times have had it all the way down when it has started. Sometimes it helps and sometimes it doesn't, this is why I haven't been able to narrow down what needs adjusted.

 

[.94 OR]

I also remember fighting the IAC steps. Get those under control first.
I initially had a rebuilt points dizzy in mine. Once I got to watching the number readouts I knew something was wrong. Picked up a DS dizzy/box and it cleaned up the ignition and it would cooperate.