Lesson learned on Fitech

[flyinlow]

I pulled the trigger on an Fitech system and fuel center about 2 months ago and it arrived 2 weeks ago. Installed the fuel center first, then got to the throttle body last weekend. I should give some back ground first. 3 years ago I installed a MSD digital 6AL. It has worked well. It has a rev limiter I set at 6200 rpm. It has a rev limiter verification function  that sweeps the tach to 6200 rpm for 3 seconds after the ignition is turn on if you do not i start the engine. The intructions  had a note that you should not use this feature if you have after market EFI. At the time I had a Holley on the engine so I disregarded and promptly forgot the caution.

I started the engine after  the Fitech install. It was idling slow but running well. I had a fuel leak at the fuel center so I shut it off. My Wife cycled the ignition on and off the operate the pump to help find the leak. About the 4th cycle I noticed the throttle body overflowing fuel . I did not know at this point that we had pumped about a quart of fuel into the back four cylinders. My Wife hit the starter and the engine liquid locked. The next day I drained the fuel ,looked at the pistons with an inspection camera , installed new plugs , changed the blown 200 amp fuse on the battery ground strap in the trunk.  After this there where several calls to tech support. So what happened?

Every time we turned the ignition on the fuel pump did its five second prime. The MSD box was busy sending a 6200rpm rev limiter verification signal to the tach and the FItech ECU which then injected fuel at the 6200 rpm rate. A lot of fuel for engine that is not running.

I was lucky, no broken pistons or starter.

If you install this system, disable the rev limiter function of the MSD box.

[1974dodgecharger]

Wow thx for that info.....I plan to get fitech..

[myk]

Wow lucky break...

[tan top]

thanks for the info 

[Mopar Nut]

Good to know, thanks.

[garner7555]

Not trying to be a downer, but when one hydro-locks it normally bends a rod instead of damaging a piston.  I hope this is not the case with yours!  Just wanted you to be aware of that in case you get a vibration when it starts.  The starter alone doesn't usually bend a rod, but say if one cylinder has fluid on it and the engine fires off on the other cylinders for a split second it will nearly always bend or break a rod.

[flyinlow]

Not trying to be a downer, but when one hydro-locks it normally bends a rod instead of damaging a piston.  I hope this is not the case with yours!  Just wanted you to be aware of that in case you get a vibration when it starts.  The starter alone doesn't usually bend a rod, but say if one cylinder has fluid on it and the engine fires off on the other cylinders for a split second it will nearly always bend or break a rod.

I already have been down about thinking about those possibility's. So far the engine sounds ok. One quick WOT application and it sounded normal. I think the fuse I had in the system may have helped and it did not get much of a run before it stopped cranking. I had lost a couple days of my vacation week to a flu bug and was working late trying to make up lost time. I should of slowed down and checked things out.

Maybe this was my subconscious way of getting that stroked kit I wanted.    

[crj1968]

    Wow that's pretty crazy.  Glad it sounds like no damage done!

[John_Kunkel]

Every time we turned the ignition on the fuel pump did its five second prime. The MSD box was busy sending a 6200rpm rev limiter verification signal to the tach and the FItech ECU which then injected fuel at the 6200 rpm rate. A lot of fuel for engine that is not running.

Something doesn't sound right. Did the tech tell you that's normal?

I have an MSD distributor that has the same rev-limiter function (tach reads the limit when the switch is turned on) and it doesn't affect the time of the prime in the FI Tech. In fact, the pre-start prime in mine was too weak and I had to reset the prime with the hand-held controller.

[General_01]

I think the MSD site says that the tach limiter in the distributor runs a "clean signal" for use with efi systems. The directions for the MSD ignition box(mine is a 6425) does not say this. It says the signal from the box can do what it did to the OP. Luckily I was putting in the MSD ignition box at the same time as the Fitech unit and saw this warning.

Glad it sounds like everything is OK. Scary situation. 

[flyinlow]

Something doesn't sound right. Did the tech tell you that's normal?

I have an MSD distributor that has the same rev-limiter function (tach reads the limit when the switch is turned on) and it doesn't affect the time of the prime in the FI Tech. In fact, the pre-start prime in mine was too weak and I had to reset the prime with the hand-held controller.

Mopar electronic distributor, MSD 6425 ignition.

One tech (Bryce)   thought at one point that the ECU was getting a spurious rpm signal. He thought there might be corrupted ECU, so he walked me thru as reset. After this the start up sequence of the fuel pump running for 5 seconds and a a small prime shot from the injectors with the "click" occurred. I ran the engine until warm. Shut off and restarted a couple of times. Worked well.  Stopped for lunch. tried it again and it went back to the long 3-5 second prime with no "click". This puts about 1/2-3/4 inch of fuel in each bore before it dribbles past the throttle plates in to the intake.  At this point I am ready to put the carb back on.  I talked to Bryce again he said they needed to test the system (return it to Fitech) . I cycled the ignition on again and happened to see the rpm on the handheld go to 6200 rpm for about 3 seconds (with the injectors spraying like crazy.  Hummm. Dug out MSD instructions and reread. I disabled that feature.  I am not sure why the unit worked normal after the reset and then later returned to the problem.


Today , Fitech called me and I talked to a different guy. He said they have had that problem crop up other times.

Their Tech support has been good .( They are very busy. )

I just wanted to mention this to save some aggravation. I drove the car more today and it continues to learn and drive better.