can a jimstim be used to give a 1227730 ecm the correct distributor signal to work and give injector pulse ? Does the ecm just need a 5v pull up and rpm tach signal to c7 bypass and what goes to dist reference high ?

 

Yes, I use a JimStim on my test bench, works great.

The pots that are supplied don't last long, but are good to start with.

Just use the basic distributor setting for tach signal.

 

how do you get the ecm to give a injector pulse with a just a tach signal ?

 

That's all the ECM needs, well that and MAP and a few other sensor inputs.

 

sorry Im new to this and just a little confused. So out of the 4 wires that the distributor uses for the hel module back to a 1227730 ecm witch cavity do I hook the tach signal too ? I just set the jim stim to a v8 setting for the wheel and all the dip selections to the one side Distributor/EDIS ? Again Thank you for your help here

 

I also use a Jim Stim on my test bench. The Jim Stim was originally used for testing the Megasquirt EFI. It simulates inputs into the ECM based on sensor inputs. Sounds like you are trying to hook a distributor up to it or use it as a controller. Not sure but don't know if it does that.

 

I would like too just use the stim wheel as a output for to a 1227730 ecm Im just unsure of the jumpers and if this can be done . Pictures would be great If you are using the same setup.

 

is it just a vr tach signal to d8 of the ecm? and use a 5v from the jim stim to c7 ?

 

Im not sure if the JimStim can produce the est signal I think Its is a 5v dc square wave.

 

Just connect the tach terminal on the Jim Stim to D8 and you're in business. forget about the C7 EST bypass. That will provide the tach rpm to show in TunerPro. I hope that's what you are asking.

 

Go to http://www.diyautotune.com/tech_arti..._assembly.html

They have a very good manual for the Jim Stim.

 

I just followed the instructions for connecting an MS to a GM ignition pin out. I've used this on '7747, '299, '7730, '7749, probably a couple others, $42, $58, $8F, $59, $8D, etc. Works fine.

 

Correct, you need to wire in an EST module for correct operation.

 

is there a write up on what to do sorry kinda confusing. I just got a 1227165 ecm and want to make 2 harnesses and use them jim stim on both setups. I need to get some new pots these suck the rpm one I have to hold in at a angle to get it to work. Bye est module do you mean the one on tbi and older tpi cars ?

 

You're over thinking thinking this.

Just look at how the MS gets wired to a GM ignition (in the megamanual) and use those pins for your ref hi and ref lo, it's that simple.

Think about it, the JimStim is meant to test a MegaSquirt, before being attached to the engine using proper and simulated signals of what the actual engine will produce, it works just fine.

I have a few harnesses that I swap between for different ECMs, to use with the JimStim, it's a great way to do it.

I still need to get a case and swap over to the new pots.

 

Not sure how your doing it Six? Or if newer Megas are differant?

I did this a long time ago and ended up with 12 volts going to ECM which did not last long... just looked at MegaManual and shows possibility of 12 or 5 volts for ignition!

In doing conversions long ago with fuel only we found real quick that a Tach Filter was needed to supply ECM with 5 volt square wave.

The EST/ICM module puts out a square wave 5 volt signal. There's a lot going on in the module which may not make a difference in running on bench with JimStim but to easy to wire in and get proper signal.

You need to be careful doing all of this as I acedentally introduced 12 volts back to JimStim and fried a chip and resister or? This was all a long time ago and I didn't do any writeup on it... HTH!

 

Im even more confused and may have jacked up the JimStim or the 1227165 ecm. I tried it like you said yesterday EagleMark and took a esc module and hooked pin B of the module to the JimStim 12v and D to ground. I hooked pin C to the ecm B7 I started to get a rpm reading but it was bouncing from 300 to 950. After I did this I took out the esc module and hooked it up like sixshooter said the MegaManual said pin 30 Fidl or 36 ign I tried them both and nothing. Hooked it back too the first way and nothing. So I guess I fried the ecm or JimStim Where does the tach filter go ? and do you think this might stabilize the rpm reading ? The only jumper I have is to vr and the dip switch is all off. You guys are a great help Im glad it has been done before But im al a loss now I better order another cpu and find a ecm ;(

 

oh I forgot to mention in above I have the tach from the JimStim going to B5 ref high of the ecm.

 

Sounds like you fried the JimStim ECU like I did before using the EST/ICM module.

Wish I could help but it was long ago and I don't even have a JimStim anymore. Their manual and forum was very helpful when I did this. New CPU and resistor (?) was very cheap...

 

sorry too be slow. so did you just use a distributor remotely to get the distributor signal to the ecm ? I just dont see how to wire the schematic you put up above. I did find a picture of the corvette tach filter looks easy to build just a few resisters and a few caps.

 

I just wired in the EST from a small cap distributor laying on bench. Don't forget to ground it.

The Corvette tach filters are for tachometer. I don't think anyone sells a EFI tach filter anymore. No reason to use them as conversions use external mounted EST.

I can't even find a picture of it wired in?

 

ok, I hope Im following here, great news it was just a bad connection on my esc module it's back to going from 300 or so rpm to bouncing to 950 rpm. If I understand this correctly If I take a small cap hel module and just apply 12v to the small side + and hook up the est ,bypass and ref low to the ecm and add another ground besides the ref low to the module mounting tab. I also would then need to hook the JimStim tach signal to the reference of the ecm ? The efi tach filter what vehicle would that be found in ? Were does it get wired ? So sorry for so manny questions just want to get this working right.

 

It must be a invisible module on your test bench, lol Nice looking setup

 

There is no EFI tach filter, it was made by aftermarket EFI conversion companies to supply ECM with needed DRP signal to fire TBI injectors. The GM EST/ICM is the tach filter in stock applications.

I really wish I could remember more to help... I did find all the info needed from the manual.

EDIT: Here it is in wiring...

 

I think I found the tach filter you were referring too and a schematic it uses a MM74HC14N

Component description.
1. Light blue body.
Bands are Red, Black, Black, Red, Red
2. Orange colored body
Black band is oriented to the bottom of the schematic.
Appears to have letters/numbers above band
First line Z0
Second line N1
3. Light blue body
Bands are Brown, Black, Black, Red, Brown
4. Light blue body
Bands are Red, Black, Black, Red, Brown

Components A & B are the same. Small rectangular components with yellowish body. Component number is oriented on the board as per the schematic. Number is 45C104K.

Large chip has a sylized F and then the numbers (first line) P0242SD and (second line) MM74HC14N.

Wires out:
Black - ground
Blue - B5
Red - C14 (5v ref)
White - Tach (neg. post on coil)

 

what does the efi tach filter do?

 

I found A link to that article That I believe those pictures are from

http://www.justih.org/Binder-Bench/s...ead.php?t=4780

 

You don't need a filter or any extra modules to get the JimStim to feed a Delco ECM/PCM, all of the signals are produced right on the JimStim with no extra filtering or signal manipulation needed.

Pretend your '7165 is a MS, and connect the appropriate pins of the connector (or screw terminals) to the matching inputs of the ECM. This should really be quite simple.

 

So that thing can be used as a fairly cheap ECM bench..

Looks like all you'd need is a pot for MAP..

-- Joe

 

That's exactly how it can be, and is used.

I use the "spare" pot for MAP.

 

Just noticed that. Mint. I think I'll buy one.

-- Joe

 

You'll want to upgrade the pots, eventually. They are good for short term testing, as in one or two ECMs, then they tend to show their "quality". It makes sense, since it is really intended for the hobbiest, who just assembled their MegaSquirt, and not many hobbiests build more than one unit.

 

Havent had time to work on the JimStim any more but I think I need to buy a usb to aldl and use tunerpro. I have been using winaldl with this 1227165 ecm maybe thats the issue with rpm fluxuation.

 

Just got done installing some new pots and this stupid thing is still doing rpm fluxuation. It holds steady most of the time and every now and then it dips too 300 or 500 rpm. I can only get up to 975 rpm is this how the jimstim is designed ? Could the ecm be dealing with a alpha-n condition with no maf signal ?

The only way I can get a rpm signal is to have it hooked up like this. esc module and hooked pin B of the module to the JimStim 12v and D to ground. I hooked pin C to the ecm B7 . The tach from the JimStim going to B5 ref high of the ecm.

Eaglemark says too hook it up one way, sixshooter another and utilityguy said just the one wire. Is this even possible todo any one have pictures of how too hook it up I still can't figure out how the megamanual applies.

 

You don't need any additional modules, the JimStim will trigger the ECM directly. You need to use the ref hi and ref lo wires, just like the MegaManual shows for pin connection. You're over thinking this.

 

I guess I can't find the information is it on this page ?

http://www.megamanual.com/ms2/GM_7pinHEI.htm

 

That's the page, the information is there.

 

I have one wire going from D8 to the tach terminal of Jimstim and it works just fine. it's the purple with white stripe in picture. I actually have two going to same terminal for different connectors so it works on 165 and 730 ECMs.

 

Thanks for the picture utilityguy2. Thats exactly What Im trying to accomplish the 1227165 ecm and the 1227730 ecm I still don't see any more info on that link sixshooter. I just purchased tuner pro rt today and Im hoping I purchased the correct cable to connect to the ecm. I have been trying with just the 165 ecm and winaldl through 160 baud. If I understand correctly the 730 will connect through the 8192 baud on the ecm. What do the shuts you have on the pull up for? Looks like you have the extra shunts on the rx and tx ?
http://www.ebay.com/itm/250736677870...84.m1439.l2649

 

They are for a 12v tach. I don't know what that cable would be for.

I just wired a aldl plug into the harness and use a USB aldl cable from Moates.

Maybe we are all confused on what you are trying to do. Are you trying to hook a distributor to the Jimstim. It's not needed. Jimstim simulates all needed sensor inputs to the ECM.

 

Like I said I hooked up the tach wire on the jimstim to the purple and white on the ecm and no tach signal was present until I added the esc module. I was using winaldl and there schematics. I tried m cable I made on a friends 1227747 truck ecm and it worked great so Im not sure if my JimStim is jacked up or if its is winaldl. The cable is for usb to uart so there is no need for a interface cable like this to connect to a gm ecm and tuner pro ?

 

I was thinking transmit and receive on the same bus line and ecm ground should work maybe im incorrect you guy's are the pro's

 

The tach connection does not connect to the purple and white wires.

I'll give you a hint, look at the picture (in the MegaManual) with the ignition module, look at the connection to the Mega Squirt, it should be crystal clear.

 

I think we are talking different things. On a 730 Pin D8 purple and white wire goes to the Tach on 165 it's B5. Just hook it up according to the ECM wiring chart, use TunerPro and it will work. It is that simple. At least that's what has worked for me for last couple of years.

 

Have you gone here for the instructions? http://jbperf.com/JimStim/index.html

 

wow two different stories this picture has any one done this with winaldl ? I feel like you guys are avoiding the answer. I appreciate the help but feel like I have to keep hounding. maybe it is just the one wire hookup and the JimStim is messed up. Should I be able to get more that 950 rpm ?
Did I purchase the wrong cable too hook too tunerpro ? To answer utilityguy I did look at the manual page but what more information is that giving me ?

 

I guess I have to spell it out, the purple/white wire goes to pin 24, the white wire goes to pin 25 or 36 (IIRC these are tied together on the JimStim).

It's really quite simple, the JimStim acts like an engine sensors and actuators in place of the real thing, no extra modules, no extra filters, no extra parts needed. The only extras that would be "needed" are for testing those specific inputs and outputs, such as testing a boost control solenoid, for true functionality, or an ALDL connector to make connecting with a datalogging program easy.

The ALDL cable will not affect what RPM is displayed, it will work, or it won't.

 

Not avoiding anything. Hard to understand what you are wanting. I only told you what works for me. Are you using both RPM pots? the fine and the course? The course will do thousands and fine 100s more or less.

 

I now have tach signal to the ecm in the range of 2050 rpm to 6375rpm max and is very stable. The fine tune will allow me to make all the changes but changing the rpm c does nothing. Is this normal operation or should I be able to get a lower rpm? I tried both spots too hook up D4 and always get the code 42.

 

I measured the Rpm c voltage in at 3.30V and the output range is from 0-3.3V . Is the rpm correct on what I am getting ????