Anyone using an MSD ready to run with Fitech ?
Curious if anyone has a ready to run setup with their fitech and if they have experienced any idle surging problems ?
A bit of a story first. I have a 30004 and set it up originally with a duraspark distributor modified and locked out to use the fitech for timing control. I installed the distributor with the engine at 14 BTDC and set the reluctor blade so it lined up with the pickup (with rotor lined up at #1) so this was my base timing. It worked quite well but I found that cold starts worked the starter quite hard almost kicking back (rough feeling).
From what I gathered this was probably was due to the amount of advance I set it up with and the fact that the fitech wont retard the timing on start and therefore can not be any lower than the 14 BTDC no matter what settings you enter in the handheld. This is the way I understand it anyway. However I have determined my engine likes the 14 for idle and this does work out decent with the 20 deg maximum advance from the fitech which puts total at 34 or so. Its just the cold starts I don't like.
So I decided to experiment and install my MSD 8503 e-curve ready to run to see if it would improve my starts and also because the fitech spark table is a bit limited and I could use the vacuum advance again etc. This MSD distributor worked great when I had the carb installed. I setup the fitech to TACH instead of VR coil and switched to the blue wire. It fired up fine (not as hard of a start which was good) but now when its warm at idle it slowly develops about a +/-100 RPM continual surge that I cant get rid of no matter what idle control settings I change. It also seems to struggle with the 20 rpm for the fan adder when activated. The IAC steps are good fluctuating around 3 to 7.
When you step on the gas a bit its fine but will settle into this surge after it idles a bit. Driving me crazy, just doesn't seem this MSD wants to co-operate with the fitech for some reason.
Anyone seen issues like this ?
Comments/suggestions ?
Thanks in advance
Interesting dilemma. I am running a locked-out MSD distr. Once I installed the FITech I removed my Mallory box as the FITech didn't seem to like the tach output. Wish I could be of more assistance.
Thanks for that I hooked the blue wire to the tach output on the MSD and also tried wiring to the negative on the coil with my 8503 distributor and same surging issues. I am wondering if it has anything to do with the multiple sparks at low rpm with the MSD ?
I went back to my previous duraspark locked out setup and it runs perfect no surge just to verify. I tweaked it back to 12 deg for base timing and set the handheld to 14 for idle but still getting harder starts.
I am thinking I might try another ignition module and regular distributor to see if I experience the same issues to eliminate the MSD factor.
Well I tried going back to my old duraspark ignition module and distributor and found roughly the same idle surge issue, although was not quite as bad as the MSD. I set base timing at 12 deg and starts were nice and smooth probably because of the start retard feature.
One interesting thing I did find which helped improve the idling surge issue was lowering AFR idle target by almost a full point to 12.5 from 13.5. This did smooth things out considerably so that is interesting.
When I used the Fitech for timing control it would idle very nice in the 13.5-13.7 range. I wonder if the Fitech idle stability feature helps this ?
I would like to use the Fitech for timing as it seems to run better but the cold starts are just too hard for my liking. The only option for best of both worlds (ECU timing control and start retard) I can see would be to use the Fitech to trigger an MSD box with a start retard feature. However that would add a lot of extra equipment and cost.
Curious anyone else has seen these types of issues or what equipment they run with what results etc ?
I kept it simple. High power HEI distributor from Performance Distributors with tach output terminal. No timing control.
Sure in my case it seems to be a bit of a trade-off here.
I am leaning towards just using my MSD ready to run rather than going all out and buying a bunch of ignition stuff to make the starts better etc. However I do like the Fitech timing how it idles smoother at the higher AFR.
I have read about other people also having some issues with hard starts and starter kick backs too. My engine is a fairly mild 347 build (10:1 and a bit of a cam) but still seems to struggle on cold starts with the Fitech. Perhaps the 14 deg base timing would be totally fine with a more stock setup.
It is too bad that Fitech didn't (or couldn't) incorporate a small crank retard setting in the ECU software. Not sure what that would involve but it seems to me all you would need to do is delay the firing of the coil when the magnetic trigger picks up by a small amount when it senses cranking RPM...then again too much delay and perhaps the exact rotor phasing/positioning would become an issue.
Discussion is welcome !!
Thanks
IF the advance at idle is giving you trouble (hard start) simply go in and retard the distributor to where it likes to start
reset the "Dist base deg" to this new number
Set the VR number at 4000k rpm
set the "Idle advance" to your needs say 14º
no need for a retard unit.. MSD works fine.. I have been using the MSD5 street fire units as there is no need for the function of the AL6 units (7's are incompatible and will fry the ECU in the FiTech)
Yes like you say I thought about retarding the distributor some more and re-phasing the rotor etc. However from what I understand after reading up on it a bit is that the fitech will only do a maximum 20 deg advance curve.
So if this is the case if I retard to (say 8 deg BTDC) start then it will only do a max 28 deg total advance and I was hoping for more like 32-34 deg etc.
Can anyone confirm that this is the case and the Fitech spark curve will limit out at 20 deg max from the initial base ?
Thanks
I run a billet locked distributor at 38 deg, a msd 6al a msd start retard, and a 3 step timing retard at first start it surges about 200 rpm then once it figure out where it want to run smooths right out
Did some experimenting with my ignition setup...
Setup the Fitech to VR coil for ignition control as normal.
Wired my locked out distributor mag pickup (set at 12 deg) in parallel with the Fitech input and my duraspark ignition module so that each one gets the same two wire pickup signal. I then wired up a separate "crank" relay (coil) that energizes on key cranking and which also triggers the 5 deg timing retard built in the duraspark module.
I then wired the crank relay contact "common" to the ignition coil negative, the NC contact side to the black Fitech coil wire, and the NO contact side to the duraspark so that the coil signal will switch with the crank relay.
Sounds confusing I know...but in effect the Fitech fires the coil when running and the durapark fires the coil 5 deg retarded when the crank relay is energized (cranking/starting). Once the engine fires (on the 5 deg retarded Duraspark module) the key is released and the crank relay switches to the ECU signal from the Fitech to fire the coil.
The crank relay contact isolates either coil signal from conflicting with each other when running and the failsafe (if relay doesn't come on for some reason) is fire coil from the Fitech.
Works awesome!!
My cold starts are so much improved and the Fitech seems to catch it nicely after you release the key. It doesn't seem to know you are firing it off the duraspark module for those initial few seconds on starts.
Tried it for several starts now and I am pretty happy its working nicely.