Trying setup EFI via FAST XFI system. This is the rundown so far with it.
I am having issues getting this thing to fire up. Its a reher-morrison 540 with a 4-7 swap cam. I wasn’t aware of this at first so I hooked the system up as it would be normally on a bbc. Car would crank, stumble but never fire up. I then found out that these Morrison motors all have the 4-7 swap from talking to them on the phone. So I swapped the firing order in the tune, repinned the #4 and #7 injectors, and reran the plug wires. Now the car will crank, but wont even try to start. I have rechecked the timing of the distributor multiple times and gone over all grounds etc. Everything seems to check out ok. The only few things I am seeing that could be causing an issue are these:
-The injectors are firing bank to bank according to the lights on the ECU (tune says its on SEFI)
-When hooking up the timing light to the main power wire to the distributor it fires the light ever time. When hooked up to any of the plug wires the fire is weak and inconsistent. When I received the kit the distributor cap was broken and FAST sent a new one…Any chance the distributor may have been FUBAR as well?
Any help would be greatly appreciated. This car is heading to the body shop in the next few days, and it would be alot easier to get it on the trailer by driving compared to pushing.
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May be getting weak spark from a faulty distributor but how is your base fuel map? getting a motor to start is really dependent on the initial fueling rather than timing as long as the distributor was installed correctly. As long as the timing is “close” the motor should fire if the fuel tables are “close”. This has been my experience with both of my EFI motor builds so far.
I have put the distributor in wrong before and couldnt get the motor to fire, so double check the distributor is set to fire on the #1 cylinder at TDC, and if thats correct, the fuel parameters are what you have to play with to get it to fire.
keep adjusting the fuel tables and start up fueling tables. I havent seen FAST programming but should work on same principles as other EFI. Getting a cold start can be difficult so keep adjusting fueling to get it to fire. Needs to be rich to cold start but not too rich you flood it Finding that balance can be time consuming.
Properly tuned, I think you will enjoy the EFI’s driveability. Smooth starts, idles and decent gas mileage if any of that is a concern. Not pulling carbs apart for jet changes is also very nice in my book.
i agree with the advantages of efi. but for this particular car it doesn’t flow well to me. with full tubs, bare bones, no power anything and a snorkel hood i think it needs a 10-71 blower with 2 carbs. and with the huge cam im sure it has might be a little pita to tune efi.
Finding that balance can be time consuming.
