waffling, venting and just bouncing ideas.
65 coronet 440 convertible.
it runs and drives, but hasn't got the best track record for reliability.

I cobbled together the cheapest efi setup I could way back.
It is a megasquirt II on a stock 5.9 magnum.
but it always has had odd issues.
like occasionally when warm it will high idle and won't come down till after I put it in gear and chirp the tires.
or put it in reverse and it dies, but only every once in a while.
weird idle pulses that I thought I fixed when I took out the pcv from the back of the throttle body.
I replaced the painless performance perfect management system , which I still have sitting in a bag, but that too had issues.

now that there are more supported and better ones out there, I thought I might fork over the cash to upgrade.
but I can't see spending the nearly 3k to keep it mpfi.

it looks like about 1500 to swap to a tbi efi setup. fitech or summits
since I am well under the 400hp or even if I step up to the 600hp setup it isn't that much more.
that is the correct carb intake at 500 bucks so I can keep all the original accessories and a/c plus the efi for around 900 to 1000, and misc stuff to put it back the way it would be for a carb, like the throttle cable and kickdown linkage.

I also crazy looked at the stuff needed to make it a 5.7 bolted to a 727 and if I can find a 5.7 cheap enough, order the hotwire kit or the diy hemi wiring harness and computer, I think I can do it for right at 3k, lol.
I just can't tell if these hemi ads are scams or bait and switch, where they show them for 700 bucks.
thought about this too because I can't be sure if the 5.9 has issues itself causing this and I just can't track it down, and would have the same problems after swapping to another efi setup.

I also just got the coolant system buttoned up, and hate to tear the car all apart again. and am just lazy. lol.
ugh.

I too have had some weird issues with my megasquirt for my gen 3 hemi. I have really wanted to switch to the Holley terminator x. but funds are tight.
the one problem i have is after running the car and it is good and warm when i put in reverse it will idle up and stay that way. really odd.

Side question: have either of you asked for help, with a log and tune, in the MS support forums?

I have when I first set it up.
generic questions there are a lot of help out there for.
when you start getting to specific tunes, it becomes a little more hit or miss.

so like the initial setup, indexing the distributer, I broke a part off my board, and they helped me find the part and get it going again.
the spark control stopped working, and they gave me instructions on how to re-route it.
so if you have a specific question about the board, programing, best connectors etc.. really great.

but my 5.9 is idling high after warm up gets generic trouble shooting that doesn't really help. but to be fair, it could just as easily be something I missed on the engine as the efi setup.

Is the 5.9 modified? If it isn't you could always go back to a factory computer. Seen plenty of swaps where they take the entire harness and computer over.

Also, I don't think the Summit TBI units do timing control.

The Holley Sniper with a Hypespark distributor is the best value throttle body injection on the market these days. It has a lot of features for the price. The Terminator X is the next step up and it is a higher quality product with more features but you pay more. I've had a Sniper on my car for 7 years and it works fine. They do require some maintenance so don't be surprised if you have to replace a sensor occasionally. The Sniper uses OEM parts, but for some reason the OEM parts don't last as long on hot rods as they do on production cars.

That's because production cars use sensors that have to meet the OEM requirements. Hot rod stuff uses lowest bid junk.

I usually buy the OEM sensors. My source

You can get the OEM sensors there, spec sheets on the sensors, the proper connectors needed to install them.

Or you can just buy autozone crap and butt splice things and wonder why you get funky behaviors.

Noise matters and I'll bet that is the OP's issue.

the modification to it are the distributor. it has a shutter wheel in it now.
takes the place of the sensor over the hole in the transmission wheel for the crank.
I thought about going back to the stock computer, but I am pretty sure it needs that sensor and input. I still have the old 727 in it, so I don't think that works.
it would be a whole other swap to get a new transmission fitted, since they don't fit in the old car tunnels.


I guess the sniper is about 150 bucks more. so not too bad. bringing it from 1500 to 1650.

the terminator x one is a whole other thing, brings the total cost up closer to 2500, because I would need the distributor too.
which isn't what I was looking for, since it is a stock engine. and I didn't/don't plan on doing a lot of power mods to it.
it saves having to swap a bunch of parts though. it is a straight up re-wire with a distributor change, vs new intake, new throttle cable, kick down and associated re-wiring.

I think the crank trigger was mounted on the back side and there was a notch in the bell housing for the wiring in the top. Don't know what it entails, but you might just be able to notch your existing transmission and put on in.

I'll second what Andy says though. Been using a Sniper with their ignition box and distributor. Works great.

I'd like to add that the factory stuff has to meet a Federal mandated warranty for all that stuff and the after market is some kid in china making the parts.

it doesn't say, but do you need to use their distributor and spark control?
have an old unilite sitting around I could stuff in.
otherwise that adds another 500 and some change.

No, I have a Terminator Stealth using a FBO distributor and ignition box.I would think the Sniper is the same. The 650 HP kit was around $1600 a couple years ago

I'm pretty sure you would need a PCM from a manual transmission vehicle to run a 727. Someone please correct me if that's not true.

Yes.

That's your idle air control (IAC). Take it apart, clean it with oven cleaner and re-try it. If it doesn't work, they can fail completely: get a new one or try one from a known Magnum engine that idles normal.


Sniper tree'd me here; Him and I think exactly the same on this stuff: but yes: it's aftermarket JUNK you are dealing with and the NEW aftermarket JUNK won't be any better.

Just a personal opinion. I would stick with a carb. Everyone I know who has gone to efi regrets it, that includes fitech, holley and others.

it was never carb to begin with.

is the terminal x universal, or do you have to order a specific version to be universal?
someone near me is selling one setup for a chevy, for 700 bucks. seems like a deal even if I have to get the harness for my specific injectors.

I am not sure this helps your problem, but I think I figured out my high idle after it warms up.
or rather I messed it up worse. lol.
There are fuel add settings after start up in idle.
I dropped those down quite a bit at the warm coolant level. but based on this video,
https://www.youtube.com/watch?v=bu2adw5sBAE

I did that wrong.
I just kept turning them down and restarting the car and the high idle went away.
but now after I let it sit a few min, it won't stay running after I start. so I turned it down too much.
have to wait for my laptop to recharge to mess with those settings again.

I also have a weird off idle knock going. clatter really, just as I tip in the throttle off idle, it just clatters and then goes away, pretty fast, like a 1 count and gone.
guess due to the outside temps, the timing might be too advanced that far down under load. have to play there too.

still don't really have an answer if I can repurpose a chevy terminal x to a mopar just by buying a harness. holley's site is a bit confusing on that. probably have to find one of their fourms.