HEI setup

BooBoo · Post by **BooBoo** » Mon Apr 24, 2006 7:00 pm

I just replaced my jeeps 258 with a AMC 360. The 258 had a MSD ignition and the new 360 has a HEI. The MegaSquirt II was running perfectly on the 258.

The HEI has two terminals for wires BATT and TACH. I hooked the BATT to a 12V swiched source and the TACH directly to the tach on my realy board.

The engine will not start. When I used to crank over the 258 the RPMs in MegaTune would register. WHen I turn over the 360 the RPMs don't move at all.

Did I hook this up wrong.

BooBoo · Post by **BooBoo** » Mon Apr 24, 2006 7:45 pm

It is a 4 pin.

BooBoo · Post by **BooBoo** » Mon Apr 24, 2006 8:18 pm

- W - the white wire on the VR pickup,
- G - the green wire on the VR pickup,
- B - 12V,
- C - Coil negative terminal and tach.

Note that the coil negative terminal is used as the tach source, so you have to install the Hall circuit (assuming this is a V3 main board) as if you are running off the coil negative terminal.

Can I assume that the "C" goes to the TACH terminal on the outside of the cap?

This is a MSII not a V3 board. Do I still ahve to install the Hall circuit? If so, were do I find info on how to do it?

BooBoo · Post by **BooBoo** » Mon Apr 24, 2006 8:40 pm

It does help if you tell uis these thing off the top. Above every post entry dialog is this test: Please note in your post if you are using MS-II/MS-I/MSnS-E, the code version, MegaTune version, as well as V1.01, V2.2 or V3 main board, etc. In this case, the processor, main board, and ignition set-up are all important details.

I did mention it was a MegaSquirt II in my first post in this thread. Re read it.

This may be connected to the tach terminal on the3 distributor, but sonce this isn't a GM distributor, I can't be sure.

This is a GM distributer, it has a different shaft attached for the AMC.

BooBoo · Post by **BooBoo** » Mon Apr 24, 2006 8:46 pm

OK, sorry.

Is there someway for me to find out how to hook this up?

BooBoo · Post by **BooBoo** » Tue Apr 25, 2006 7:40 am

Now it appears that I have it hooked up correctly. How can I test that I am getting proper or anything out of the HEI? Can I hook up a meter to the TACH terminal?

BooBoo · Post by **BooBoo** » Tue Apr 25, 2006 4:30 pm

I put a volt meter on the TACH output of the distributer. It reads 12V when I turn on the ignition. It goes to 8V when cranking. The MSII showes "not cranking" when it is.

BooBoo · Post by **BooBoo** » Tue Apr 25, 2006 5:23 pm

I have spark and I get voltage all the way to the MS. I am thinking maybe I don't have the Ignition settings correct in MSII. I can't seem to find any info on what to set them to for a 4pin HEI.

BooBoo · Post by **BooBoo** » Tue Apr 25, 2006 6:17 pm

Here are the settings I have now.

Trigger Offset = 0.00
Skip Pulses = 3
predictor algo = 1st high rpm 2nd low
predictor gain = 20
next pulse toll = 50
Ign input = falling edge
crank trigger = calculated
coil charging = standard
spark output = going low (normal)
max spark dur = 2.0

BooBoo · Post by **BooBoo** » Tue Apr 25, 2006 6:43 pm

The board is super clean. no reason to clean it right?

I have all of the jumpers open on the MSII board.

I do not have a stimulator, I guess I have to build one.

Make absolutly no sense to me as this was working perfectly with my 258 I6 with an MSD 6a. I swap motors to a 360 with a 4pin HEI and all of a suddem the computer is bad. That makes no sense to me. Are you sure there is no other setting that I could have wrong?

krisr · Post by **krisr** » Thu Apr 27, 2006 3:33 pm

Do yourself a favour and buy/build a stim. It acts like a function generator and helps TREMENDOUSLY in troubleshooting MS build errors. I know I'd be well lost without it as it's purely guess work without it. A scope would be the next best tool but as Lance pointed out, not the cheapest route.

BooBoo · Post by **BooBoo** » Thu Apr 27, 2006 4:37 pm

I agree, I have needed to build one for a long time. I borrowed one to build my MS and did not use one for the MSII. I really need to have one on hand just in case something happens.

That being said, I really don't think there is a problem with the MS itself. It was working perfectly for a long time and was just before I swapped engines. I think there may be a problem with my distributor. The fact there is spark throws me off. Could the module or something else be bad and cause the tach signal to be incorrect?

Joethemechanic · Post by **Joethemechanic** » Thu Apr 27, 2006 10:31 pm

If I understand correctly:
V2.2 board, MSII, GM 4pin HEI running fuel only.

What was your setup for the MSD? Was it a VR sensor trigering an external MSD box or was it a " stand alone " distributor.

the reson I ask is you may have had a modified opto circuit to work with the MSD that is now incompatible with the HEI.

The easiest/cheepes way to check tach signal to the MS with Your set-up would be with a test light. ground one end of the light and probe the wire going to MS, cranking the light shold blink as the module fires the coil.

if this is the case re-check the opto circuit, if diferent components were installed you may have burned out the opto.
Joe