The REPU does make a good test vehicle. It would be pretty cool to try them both and report the differences and similarities. Tell you what, I can be of assistance in the MS department, but you'll have to ask College Boy (Evil Aviator) for help with the Motec, if necessary. Actually, I don't recall which ECU Evil A decided to use, lol.

By the way, if your REPU was like really close to being finished with the MS in there, were you going to leave all the EFI manifolding in place and just do a harness or connector swap over to the Motec? Or were you going to swap manifolds as well? Wait, wasn't that manifold for a 4 port 13B?

 

It would proabably be easier to just use the stock manifold, since it's (1) already on and (2) a 6-port manifold. It's also more of a torque motor (if you can call any NA 13B that), so keeping long runners, a dynamic chamber, and functioning 6-ports (with Pineapple inserts) is a good way to go. Buuuuuut, I don't know. There's just something cool about an IDA-style setup. I share space with a racecar fabrication shop, so making a 4- to 6-port adaptor is not a big deal. I would use the IDA-style setup on the GSL-SE w/Haltech, but for that I was planning to use a Chevy LT1 Throttlebody mounted DCO-style across the top of the engine, with the IC plumbing wraping around on the drivers side. Hmmm, I also have the original '75 4-port 13B from the truck up on the shelf, a rotary to Porsche transaxle adaptor, and a friend willing to cut me a smoking deal on a 914. Too many options, not enough time!

 

OK, that's one feature that MS doesn't provide. Unfortunatley, given MS has only two injector drivers, and they are typically arranged to drive primaries and secondaries separately, injector staging and this soft-cut limiter would be mutually exclusive options.

I consider "stock" any code you can download and flash to your MS box with no assembly language coding required. In that case, all those features and the low impedance injector control can be provided with MSnSExtra. That said, if you've got a proven Motec setup now, going with that may be the less painful route. If the 'bling-factor' of the Motec label does something for you, then that's a plus as well.

If you are concerned about your MS, find somebody local to check out your box and give it a run on their vehicle. I've done that for others when they've had setup difficulties. I check the box over, flash my settings to it, plug it into the harness, and we go for a drive. Then the guy leaves with a box that has actually fired real injectors.

As for Palm tuning software, there is some new stuff in the works there as well. I'm interested in this Motec interface, as it might be useful for ideas.

Sure, give that a go. It'd be interesting to hear the results. BTW, any idea on pulse width resolution?

Roger

 

To me, "stock" stock is anything that is not reflashing the ECU, outside of maps and configuration settings with the basic tuning software (i.e. just like a commercial ECU). I would say reflashing the ECU with different code is more like a "bolt-on" upgrade.

I'm just going to pull it out and check it again, myself. While I'm no tech-geek, I can usually figure things out if I invest enough time and motivation. It's just been so long since I built it (remember the days of the MS group-buys?) that I'm really going to have to sit down and read all my notes and visit the MS FAQ. If I hit a road-block, I might enlist Jeff to help me troubleshoot it. Who knows...it could just be my stimulator that was causing the funky behavior.

Cool. I should really go visit the MS Forum sometime and catch up on developments. When they shifted away from the email list, I just stayed behind.

The manual does not list any specs. It's really quite basic and is more a manual for how to use the controller; not the ECU. I suspect the rest of the documentation has gone missing, as it was not included in the sale. Unfortunately, Motec does not have any legacy-system EFI info in its web site and I can find nothing useful on the internet. Perhaps I'll give them a call and see if they know....

 

Did you clean the PCB with alcohol? I could throw it on my stim to see if everything is ok.

I didn't join the MS group until shortly after the forum had been started. It would be hard for me to keep up on an email list. I prefer forums (and their private message option) to email anyway.

Good luck finding specs for that Motec. Let me know what you want to do with your MS.

 

Congrads on winning that auction. I was proxy bidded at 700 because I was working at the time the auction ended.

Good luck with all your projects.

 

Glad you were away from the computer and didn't bid any higher! My max bid was $800 and I fully expected to get outbid by someone wanting it more, though I'm happy that didn't happen. I figure not too many people search for Motecs on eBay and those who do are looking for something newer, so there was at least a chance it would slip under the radar and go cheap.

 

How many "bolt-on" upgrades cost nothing and take less than 2 minutes to install?

 

Flashing the CPU is quite trivial. I don't understand why it could cause anyone grief when a program like Easytherm is available and easy to use. Or you could try download.exe and not even need to short the boot jumper.

I installed a set of jumper pins from a computer motherboard for even easier access, and will also probably place a switch somewhere in the car to remotely short the pins because download.exe hasn't always been 100% reliable.

 

Okay, I bit the bullet and installed the Motec on the REPU. Sorry Megasquirters, but that ECU will have to step aside for awhile -- after testing my MS-relay board harness (constructed outside, in the wind and dust, in the middle of a hot summer day, through the firewall, with *one* color/size wire...ugh!), I discovered I must have made a mistake as there was no power from the relay board to the MS ECU. Anyway, it was easier to toss on the Motec with the terminated harness and well-labled, color-coded wires that it was to re-wire the MS. At least...that's my excuse and I'm sticking with it.

So, I spent couple hours tying up loose ends, like intalling the starter and wiring/plumbing the new fuel pump (finally got the right 10mmx1.0 to 1/8th NTP 90-degree, 5/16th hose barb fitting). After that, I fabricated an aluminum mount for the Motec ECU on the little shelf at the back of the engine bay. I will now only run the DB9 through the firewall to the passenger compartment, for the hand controller.



Forgive that the mount does not look great...it's just for mock-up, after which I will bead blast and paint it to look better. The setting on my auto-dimming welding mask was set too low, so I went arc-blind about 2/3rds of the way across and messed up my TIG weld (working right-to-left).

Here is the engine bay:



I decided to use the GM sensor that came with the kit, which required drilling a 37/64th hole and tapping for 3/8-16 NTP threads.





The TPS and bracket were already fabricated months ago. If you are interested, you can find the picture gallery here: http://rx-sevenandahalf.com/misc/TPS/

The water temp sensor was a stock-replacement GM unit that simply threaded into the stock WTS location in the back of the water pump. The MAP sensor was a typical GM unit (I used the 1 Bar version, as this is an NA setup). Nothing special.

Basically, it took me half a day to wire up the Motec using the provided connectors. It was really nice having all the wires labled and color-coded. After getting that done, I had to troubleshoot the coils not getting power, which was the result of the previous owner really messing up the wiring. There were no ignition or fuel pump relays, so it took me a couple more hours to go buy some 30 amp relays, wire them to the ignition and confirm it all worked correctly.

After all that, I cranked the engine over and it lit on the first try It doesn't idle for **** yet, but I could keep it alive by giving it some throttle as I played with the Low Load maps and the TB adjustments. This is a fresh rebuild, so it requires some time to break-in. I would have played with it long enough to get the idle reliable, but the damn radiator sprung a leak, so I could only run it for about 5 minutes at a time before the cooling system pressure built-up. I did confirm, by running without the cap, that the coolant seals are holding fine, so it's just a case of the radiator having been banged up while sitting on a shelf for a year or so.

Here is the hand controller indicating RPM and the TP sensor reading (each volt seems to correlate to 1000 on the calibration display).



It will take me some time to figure it all out, since the manual I have is just for the controller, but it makes a lot of intuitive sense so I don't think it will take long to get it under control.

Not bad for two days work. Can't wait for a couple more free days to go back down and tune it...

 

Not bad at all. It makes me wonder how long it'll take me when I go to wire my MS up.

Refresh my memory; are you using a 1st gen ignition system on a 2nd gen engine because the Motec is fuel-only? Seeing that empty area above your coils just screams DLIDFIS. Otherwise, that's cool how little time it took to get it to fire up.

All three of my REPU radiators leaked, so I know what that's like. Two could be repared easily with a propane torch, and the other had a massive seem rupture that will require a little more work (it happened when the previous owner overheated the engine and the coolant seals let go allowing exhaust under high pressure into the cooling system).

 

Yes, it's an electronic distributor from a 1st gen. However, in wiring up the Motec, I realized it actually has ignition capabilities. There are three ignition inputs (one coil - and two apparently for a magnetic pickup for a toothed wheel), plus ignition output wires. It doens't look like enough for a Leading/Trailing setup but perhaps it would work for leading-only. Unfortunately, I only have the manual for the fuel-only hand controller and don't even know if that controller could be made to work with the ignition features. I think I need to contac MoTeC and see if there is laptop software for this model and perhaps a real manual for the ECU. My main priority, however, is to just get it running smoothly before I wory about ignition and other bonus features.

The radiator leak, as far as I can tell, is a pin-hole on the passenger-side end, behind the bracket. When pressurized, it shoots a nice stream of coolant through a convenient factory through-hole in the bracket, onto the side of the engine bay. My recollection is that this is the original REPU radiator that I have never previously used -- I just fixed the oil cooler mounting problem and bolted it back in. This may be a prior condition, as now that I think about it, the radiator spent no more than a day or two on the shelf, when I swapped engines. For some reason, I was thinking of my 1st gen over/under radiator that is still on the shelf after getting taken off another project. Damn memory is going quick in my old(ish) age. What was the question?

 

Ah, you're gonna have to take the bracket off of that side in order to get a flame to it. Both of my easily fixed rads had small seam leaks on the rear (side ficing engine). Infact I fixed one without even removing it from the truck. I just let enough coolant out until the level was below the leak so the coolant wouldn't continuously cool the area being heated. I had to use MAPP gas and crank the flame all the way up in order to melt the solder, but it worked. I have yet to heat-cycle it as the engine is in pieces on my garage floor, but it was water-tight after the fix.

Perhaps you could run leading only out of the Motec. I hooked a 2nd gen leading coil assembly to my MS and it looked like it would work very nicely if I were running a 13B. I'm not sure what the Motec outputs from a trigger signal, but I assume it's 12V. My MS is currently set to output 5V with a pull-up resistor, which was fine for the leading ignitor, but I could easily pull it up to 12V.

Dig up some specs on that unit if you can. I've gotta say that comparing a J-109 and Diamond coil alongside a stock 2nd gen assembly, the differences were shocking. If you could indeed trigger leading only, you'd never miss trailing.

 

Update: Last Friday I made a bonzai round-trip to Portland to pick up the overrun copies of Loud Pedal from the printer. While I was down there, I decided to chuck the stock exhaust manifold and single pre-cat I had on the REPU and install the custom long-primary (66 inches) dual presilencer setup from my old PP13B 1st gen, minus the cat-back portion. I needed to do this so I could install my dual hand-held EGT setup for tuning purposes. Up to this point, the truck was not idling though it revved up great. I originally presumed it was a massive vacuum leak, but found nothing...until I pulled the exhaust and found the LIM was broken at the lower bolt flanges. D'oh! I had somehow forgotten to install nuts on the center studs for the manifold, so only the two outter ones and two upper ones were holding the manifold on. Then, due to the leverage created by the upper manifold/TB and probably my leaning on it at some point, BOTH bolt flange areas on the bottom of the manifold cracked, leaving just the top two bolts to secure the LIM. Not good, but at least I know for sure why it didn't like to idle. A replacement LIM is on the way, so I should hopefully get that back together and running more sucessfully soon...if I don't make any more "rookie" mistakes, like forgetting 1/3rd of the manifold fasteners! I can't believe I did that....

 

Youch! I too made a rookie mistake when modding my CAS wheel. I cut the wrong tooth and had to get another.

 

Between you two I might get a good answer here so here goes.
I want to ms my 13b.re and run the ms as a stand alone. What sensors need to be changed/bought/modified so I can hook up the engine to a ms and turn the key. I still have the original coils. Also what version of MS do you recommend?