Rev-N-Nator interference

[abodyfan]

I'm running Holley Terminator fuel injection with a rev-n-nator ignition box, coil, and distributor. I was wonder if anyone was having issues with the ignition dropping out during open loop operation. I was told it was due to interference that the ignition box was picking up. The tachometer will drop a 1000 rpms when it happens. After closed loop it runs great.

Thanks
Brian

 

[67Dart273]

A more general answer is LOTS of components interfere with each other if not properly configured, known variously as RFI, EMI, etc

Even the old Mopar ECU ignition, if the distributor pickup was long enough and run close to high energy circuits, could be problematic. "Generally" very low signal sensors are isolated from ground and many times "balanced." Think ethernet cable, AKA "Cat 5" The conductors of each pair are twisted. This close twisting does two things.....the twist helps cancel interferance, and the balance causes interfering signals to interact with both conductors in such a way as to cause no signal across them.

Another good example, if you are old enough, is TV anteann "twinlead" which was balanced, and twisted upon installation

Run low signal wiring close to ground, use proper grounding strategy to prevent ground loops, and keep low signal wiring and high amperage / high energy wiring away from each other. Run them at right angles if possible

Another example is something like MSD......MSD ignition, with no other components CAN INTERFERE WITH ITSELF!!!! The high energy spark wires can induce "false triggers" into the pickup wiring and cause the MSD to refire/ false fire.

 

[abodyfan]

I've been in contact with them, I guess I'm not the only person with this issue. They are working on a remedy with a filter. I thought I would put it out there to see if anyone would know. The R/T garage has been great to work with, this is the first problem I've had. Love the product!

I'm going to check the wiring tonight to see if there could be an issue the thing that gets me it fine when its in closed loop.

 

[67Dart273]

Here's the thing, there probably IS no simple "fixall" answer, as my first post was attempting to suggest. Unlike OEM, where they assemble thousands, each install is DIFFERENT even on the same type cars by different owners. Impossible to guess what you "did" or did not do that might fix this, or whether it's actually a problem within the system.

Some photos of some of your wire /wiring routing might provide some help

Another thing, if you have not, is to wander over and post on the Holley help forum

 

[KitCarlson]

I fail to understand how EFI in open loop operation causes an ignition problem. Since it goes away in closed loop that would suggest tuning issue in fuel table, or other setting and that is dropping RPM, not the ignition. Closed loop is correcting (making adjustments in fuel) for the incorrect open loop setting(s).

The EFI system controls the pulse width and rate of injectors, noise from that would have to be really bad (FUBAR), to result in an ignition problem, and would not go away CL.

While the RPM drops 1000 RPM, that by itself is not enough to further diagnose. Fueling issues are related to RPM and MAP values, so observing those, where fault occurs will indicate the area where the tuning problem exists. I am not experienced with Terminator, but there should be ways to datalog and find exactly the difference in fueling between OL settings and what happens CL. Also what is the AFR gauge indicating when fault occurs?

Settings related to time/temperature for warm up conditions might be askew, resulting in RPM drop. This is only a guess to since original post does not indicate enough detail about engine operating conditions when fault occurs.

 

[abodyfan]

Tonight I switched out the rev-n-nator and put an orange box in and the car performed good with no big issues. Definitely could tell a difference, didn't feel the same less power and torque.

 

[71DodgeDemon340]

Had similar issue, ran horrible with the rev n nator on my 340. Acted sluggish like it was missing. Contacted rt garage and they were more than willing to help, they suggested i move the box from the firewall to the fender apron as they were suspecting interference with the ignition coil with them being so close to each other or get a dizzy and coil from them to match the box, i got tired of fooling with it and didn't want to relocate the box or buy a new dizzy or coil so i just got them to do a refund which was no hassel and a breeze to get it refunded, and put a chrome box on it and it runs perfect, just like before with the orange box.

 

[KitCarlson]

Tonight I switched out the rev-n-nator and put an orange box in and the car performed good with no big issues. Definitely could tell a difference, didn't feel the same less power and torque.

That is interesting. Typically a standard ignition is good enough if the fuel is tuned correctly. If the fuel is at the outer limits, then a really hot ignition can blast thru fouled plugs or ignite lean mixture.

The rev-n-nator messing up with EFI, is very lame. A look at the coil primary voltage using a high voltage scope probe along with the distributor pickup may reveal more about the problem. I suspect if the ignition has problem with noise from injectors switching, it would also have problem with the ignition re-triggering, self induced.

Never touched one myself, but often hear of strange problems about them, and bs about the cause. The spoken lingo is outside the normal electronic terminology.