afpreppie04

iTrader: (5)

I know there are other no RPM threads on here. I have gone over them but there seems to be conflicting information in some of them.

I have an MS2V3.0 with a Zeal daughterboard. I originally assembled it myself using Aaroncake's guide but following the directions for the Zeal. This was before the DIY writeup, my car has been down far too long (being in a different city from me doesn't help).

After assembling it I had some issues using it with the Stim so I sent it to Peter Florence to check it over and make sure it was good to go. He changed the location of the Zeal (I had it sandwiched under the MS originally) and gave it a clean slate.

Fast forward to now, it is all hooked up in the car. I can communicate with it, I programmed it with Aaron's starting values and my sensors are all functioning. However, when I crank it, I get no fuel or spark. My RPM in TS just sits at 0. I do get a priming pulse with key on.

First thing I tried was switching in the starting values from DIY's writeup, as I saw Aaron recommend that in another thread as it is a more recent article. Same problem.

When I go to the diagnostics tab in TunerStudio I get a tooth signal when cranking but no trigger signal.

I was going to check continuity on my CAS wiring and make sure it is correct (using the DIY harness from a couple years ago), but I forgot to bring my DMM from work so I will check that Thursday.

I saw multiple places mentioning jumpers that were required, such as the XG1-XG2, but then I see people saying that is only needed for working with the stim.

Currently my board does not have XG1 or XG2 jumped to anything.
TSEL is jumped to VROUT
JS9 to S12C
TACHSELECT to VRIN
JS5 to the MAPDaddy
the LEDs to IGN, IAC2A, and IAC2B

Anything jumping out as obviously wrong? I have attached the log of my tooth cranking if it helps.

Edit: also added MSQ

rolfs_7

Have you pulled the cas and spun it with a drill or something? I had two that wouldn't show anything while cranking in the engine but spun with drill would work fine.

afpreppie04

iTrader: (5)

I haven't pulled the CAS to spin it, but it worked perfectly fine on the stock ECU and I haven't restabbed it or touched it at all with the MS install. I decided to switch to MS because I put a T70 on it and didn't want to try to control it with an RTek.

I will try that too though, I just wanted to make sure my internals are straight first so I can put it back in the car and then get to checking everything else.

muythaibxr

The main benefit of testing by pulling the CAS is that if it works, you at least know the CAS is wired properly.

Then you can focus on your grounds and ground routing to get that right so that you get a good RPM signal.

afpreppie04

iTrader: (5)

Well I still have no RPM yet. I haven't had much time to work on it, but since I had the ECU out anyway, I ohmed out my CAS wiring to make sure it was correct, everything was straight according to Aaroncake's guide, I measured from the DB37 connector pins to the CAS connector pin. One of the pins wasn't seated completely in the CAS connector so I fixed that, put in some dielectric grease and reconnected it.

After verifying the wiring was correct I hooked the MS back up. Figured maybe I would be lucky with that loose pin, though I doubted it. I also pulled the plugs and found they were wet, so maybe it has been squirting, I will have to look into that more. I cranked it (briefly) to see if maybe I could pick up a little RPM signal with the faster spinning, but no luck.

Could this be a grounding issue? I relocated my battery at the same time as the MS install so maybe there is a poor ground. I looked around my coils and found some unused plugs behind my driver's side headlight. It has been so long since I put the new harness I honestly don't remember if they went to anything, but I could not find any matching connectors.

I have two green connectors which I am pretty sure are the old diagnostic connectors, one six pin connector mounted next to the fuse box, a black two pin connector and white three pin connector behind the headlight, and one other connector taped back to the harness. I'm sure one of them is for foglights that I do not have.

I also found a broken wire from a single spade connector mounted on the inner fender under the fusebox. I found a broken wire on my leading coil base as well but although they both seem to be black wires they are different, one is typical black rubber/plastic coating, the other has cloth wire insulation.

muythaibxr

Did you see my previous post? Did you try spinning the CAS by hand when hooked up to the MS?

Poor grounds are usually the #1 reason issues like this occur.

Ken

afpreppie04

iTrader: (5)

I did see it, but I figured cranking it with the plugs out would bring it close to hand spinning speeds and have the same result without having to restab it afterwards. I will go ahead and pull it to try it now though. I am going to double check my grounds too, I am 90% sure of one in particular that is not right.

muythaibxr

The point of spinning by hand was to take ground/starter-induced noise out of the picture.

Hatchet Jack

To clarify, if MS shows no rpm movement and says "not cranking" at the bottom while the starter is spinning, but when you take the CAS out, spin by hand, and MS shows rpm movement, then you're looking at ground and/or starter issues?

muythaibxr

Most likely yes.

Hatchet Jack

Turned out to be too much hysteresis in my case. Turned both pots down (as the manuals suggest ), and it fired up. Thanks for the help.

j-roberts22

iTrader: (5)

Okay I am going to resurrect this thread because I am have a similar issue although mine is seemingly not as simple as a dashpot adjustment. I have gone through and adjusted my r11,32,52,56 dashpots and it has not fixed my issue. I am getting no tach signal when the CAS is placed in the engine but when spun by drill it reads rpm signal. All of my grounds have been reground several times and currently are placed under the top mount intercooler bracket against the block. I have cranked the cas by drill while cranking the car to rule out starter noise although im sure this isn't the best procedure. The ecu is a Pre assembled ms3x installed on a s5 fc rx7 using all stock components. Any help is greatly appreciated!
-Justin

Aaron Cake

iTrader: (1)

Do you have the MS3X connected to a 12V source that is active while cranking? If it's connected to ACC, it will be cut while cranking but active if the car is powered on.

j-roberts22

iTrader: (5)

I wired it per your guide with some minor modifications to accommodate te ms3x this is the second car I've done wired the same way. The switched power comes from the ignition coils and megasquirt retains power while cranking.

muythaibxr

In my experience this can sometimes happen if the starter itself is bad.

Can you describe *all* of your grounds? How does the battery connect to the chassis? Chassis to engine? MS to engine? How many ground wires did you run from MS to engine? Did you connect several pins to 1 wire then run to the engine?

Ken

j-roberts22

iTrader: (5)

Sorry I should have been more specific I'm running diyautotune harnesses so all the grounds from those harnesses (10) go to te engine the battery is chassis grounded and the starter is grounded to the block all the body harness grounds are in the oem locations.

j-roberts22

iTrader: (5)

I did not run multiple grounds from the one pin though. I'm goin to check my engine to chassis grounds now.

camman

do you have a good ground between the chassis and engine?

j-roberts22

iTrader: (5)

Yeah double checked those grounds today. I'm totally lost I can't think of anything it could be!

j-roberts22

iTrader: (5)

What is the possibility of a bad dash pot because it seems I won't get an rpm reading under 1k with the drill

muythaibxr

IF by a bad dash-pot you mean a bad potentiometer, I'd say that if you're not getting a signal below 1k, you need to turn all the pots fully counter clockwise. You can also check the gap between the VR sensor and the wheel inside the CAS. IF everything else checks out you can check the potentiometer, but I'd say that's less likely to be the problem.

Ken

Aaron Cake

iTrader: (1)

For a problem like this, it really helps to have access to a scope which can be used to trace the VR signal all the way from the CAS, right through the VR conditioner and to the processor.

afpreppie04

iTrader: (5)

OP here, sorry for the huge delays between working on the FC, it is in my parents' garage in another city, my apartment won't let me work on it there.

I fixed the MS grounding like suggested, I had them grounded to a ground panel which went directly to the battery. I took them off there and grounded them all to the engine, as per MS directions. I still need to put a ground directly from the battery to engine, I have to get some more large gauge wire as I used all mine in the battery relocation.

I also found that the two pins I had put in (pins 3 and 4) were not fully seated inside the DB37 connector so I fixed that.

At that point I was still not getting an RPM signal so I did like Ken suggested and pulled the CAS to spin without starter noise in the picture. Still nothing, but I did notice that my BAC was buzzing. I unplugged it just because it was annoying, and spun the CAS again. Guess what? I had RPM! For just the first spin, then nothing again. Plug and unplug the BAC and I can get one spin of RPM again.

Could the battery-block ground be causing this?

Also, I have one connector that I am not sure what it goes to. I am thinking it may be for the compressor and not needed until I get a new one, but just want to make sure it is not something necessary.



The single pin connector at about 1:30 of the light. The wire goes up by the condensor and ties into a loom up there. I have a pigtail that was plugged into it but the wire was not connected to anything.

Aaron Cake

iTrader: (1)

Not sure off hand what that wire is. It won't have anything to do with your MegaSquirt install unless you've done something weird.

Now as your problem...You need to verify all the connections to your BAC. Switched 12V on one side, MegaSquirt on the other, with a diode (banded end towards 12V) in parallel. I'm going to guess there is something grossly wrong with the wiring.

You absolutely, without question, need a solid ground between the engine and chassis/battery if the 'Squirt is grounded to the engine.

gaijinrx7

iTrader: (5)

any update?