dual quad small block ford
i initially installed the system on a mild 306 ford. using msd 6a digital with 2 wire billet dist locked out for fitech controlled timing. car would start and hit idle within seconds then it would immediately start to rev and climb very fast. after the 4th time trying to start it wiped a main bearing. now i have a mild 347 with the same ignition but a new intake manifold. also have a new controller from fitech as the original went blank after this install. i am having the same exact issue. car starts but revs to the moon within seconds. i have not made any adjustments as the car has not run for more than 10 seconds at a time. i have checked the simple mechanical things like linkages and throttle cables. any help would be appreciated
Fuel pressure through the roof??? 😄
thats more info than i got from fitech. i will have to look. running an aeromotive stealth in tank with return.
That's funny, yeah, there is so much that can go wrong. First step for everyone should be a fuel pressure gauge at the fitech fuel inlet.
43 to 58 covers all of them. I run my 43 (meanstreet 800) to 58 with remote pressure regulator to give me 1000 hp capability.
i have a new fuel pressure guage coming so i have not gotten to check the pressure but i will do it this weekend
wanted to follow up with a couple emails to fitech.
first they suggested that the butterflys were completely open causing the instant rev up. yeah ok
now they are saying it may be due to the rev limiter in the 6al being set. i have it set at 6500. they suggest i turn off the rev limiter because it is "disrupting" the signal to the fitech.
i will post an update this weekend
another response from fitech today. yet this is not in any of the instruction from them
"you will need to disable the rev limiter in the 6al box. that is what is causing interference with the fitech system. the rev limiter is fighting the system."
Maybe that's your issue. The MSD has a funky way to verify the rev limiter by sending a tach signal that the EFI will interpret has high revs and inject a lot of fuel. This should only occur when the engine is not running but with the key on. Look at Page 5 of the instructions: https://www.jegs.com/InstallationInstructions/100/121/121-6425.pdf
Try checking if the verification setting is on, but it should only work with the engine off and should only be flooding your manifold so I am not sure this would be the whole issue. Maybe there is something fooling the MSD that the engine is not turning when in reality it is.
REV LIMITER VERIFICATION
The MSD Digital 6AL has an optional built in Rev Limiter
Verification feature. When the key is in the On position
(not cranking or running), an rpm signal is sent to the
tachometer to verify the unit's rev limit setting. With this
function users can be sure of their rev limit settings before
each drive.This feature is not activated from the factory. To
enable this feature, follow the procedure below.
Note: It is important to note that this feature should not
be used with EFI systems. When activated, an rpm signal is sent to the tachometer. With an
aftermarket EFI system, this could activate the injectors causing a flooding situation.