I have a 74 CJ-5 with a 304 and wanting to fuel inject it. What i'm looking at doing is using gen3 truck injectors and throttle body since I have them on hand. I may possibly put a little turbo on it later just because it'd be so easy and it'd be low boost 6-8 psi at most.
From what i've seen the megasquirt 1 looks like all i'd need. I don't have to have spark control I don't guess, but can you get your ignition trigger off the coil or would I need to put an electronic module in it(its points style now).
What about IAC? It would be nice for cold starts but probably not a must since there is no A/C and never will be.

Any info is appreciated!

 

Holley Commander is a fuel injection TB that is programable they sell for about $1600. They also have a cheaper one that works more like a carb with its adjustment for about $1000.


http://store.summitracing.com/partde...5&autoview=sku

 

Thanks for the input but i'm wanting to spend a little less money than that. The megasquirt is a true do it yourself system that starts out around $140 and with all the parts I have, I should be able to have it driving with a 8 injector multiport for $300-400.

 

Pm Parish

 

Yeah, I know he uses them. I have found that you can just hook the trigger source up to the negative side of the coil which is good.

 

It's been a while since I played with MS, but I did have a functioning setup running on my dads 72 when it still had the 350 in it I actually used a Holley TB for it I got off ebay for cheap. It's pretty easy. Sound like you got the tach signal figured out, but as for a IAC, there isn't a driver for one on the MS 1's, but there is previsions to wire in a solenoid that would be activated when first started and cold, opening creating a sort of vac leak if you will, and work with the cold start fuel to make it idle higher until it warms up. A little crude but it works.

Let me know if you have any other questions and I'll see what I still remember, lol

 

Thanks, yeah I have a Holley 2 barrel TB as well with 90 lb injectors I could use. Undecided on which since I have it all on hand.
How about the IAT, ECT, and TPS? Can you run them straight off the PCM or do you have to get the relay box they sell?

 

Ya, you can wire strait to the MS unit its self, the relay box is just like your under hood fuse box on you truck, it gives you a common place to put all the relays for the fuel pump and power supply and fuses for the injectors and stuff, so you don't have to have inline fuses and really just makes for a cleaner install. The IAT, ECT and TPS basically just pass thought the relay board. They don't NEED to go though it. It just makes it so you can bring all the wires from the MS board to one spot in the engine bay and then route them from there.

 

Ah, I see that now. I finally found the instructions online. There is so much info that you don't need out there on these things. I just want to make it work, I don't care HOW it works. It takes forever to sift through the crap to get to the meat of it. I've read some talk about it having Auto Tune. Did you ever use that feature? And is there a tune repository like others have to get you started with a tune and not have to build a VE from scratch?

 

There is a lot of info out there and i agree it is a pita to sift though it. Don't know it there is a real tune repository. The VE table really isn't that bad if you have a WB hooked up. You get a basic table setup and then you can adjust it in real time as you sitting idling and then driving the co-pilot can dial it right in to. You can get it pretty good pretty fast that way.

I haven't messed with the autotune, but should make it pretty easy too. I'm sure they hav come a long way since the 2-3 years since I messed with them.

Another cool thing is the full closed loop wide band stuff. You can set up a commanded A/F table and use a wide band to control your actal A/F with the WB. Pretty cools stuff.