Trying to start my Mopar. Almost there need some help.

[jleilich]

and you are powering it off the tps vref? what voltage do you measure on the signal pin? what pin is connected to the signal?

Yes, Ground is to the MS, 5v is the same as the TPS, and MAP_EXT is the signal

[grom_e30]

ok so ext_map is pin no 23 on the ms3x connector. may be an idea to measure the voltage on signal wire to see whats going on with it.

[jleilich]

just an observation.

When I first turn on the system. It reads the same as my barro. Which tells me it's likely working correctly right? Then when I crank it starts going all crazy. if I put it back to voltage is sits at 12kpa and doesnt budge

[grom_e30]

it should be a voltage type sensor so if it didn't work when set to voltage something is wrong

[jleilich]

I just got a noid light tester to check the injectors. Oddly enough, I only see the light come on for #1 injector when cranking.

[grom_e30]

do the rest of the injectors work in test mode? seems odd only 1 works during cranking

[jleilich]

do the rest of the injectors work in test mode? seems odd only 1 works during cranking

yeah that's the crazy part. I can test all the injectors in test mode fine.

[grom_e30]

looking at your first log the ecu thinks its injecting fuel seq pw 1-8 are all the same, and you have no sync while cranking. power feeds to the injectors or possibly drooping voltage during cranking? or a bad ground for the ms3x card maybe a few things you can test.

[jleilich]

I'm using a ground strip for all my chassis grounds

This one
https://www.ronfrancis.com/prodinfo.asp?number=GW-15

So I'm 99.9% sure my grounds are tip top. Ill go double check them though because this thing is driving me insane

also, they fire fine in test mode so they have to wired correctly right?

[billr]

I would focus on the flaky MAP signal. That should be easiest to trouble-shoot. Once you find/fix the problem there, everything else might get "healed" too. First, connect a simple vacuum gauge to the intake. Let's see if the MAP really is going terribly low. Like others, I doubt it, but it is so easy to check. Assuming the manifold vacuum is low (MAP high) during cranking, then we move on to electrical tests with voltmeter. Sensor 5V to sensor ground, sensor ground to chassis/MS ground, sensor signal to sensor ground; all those while the engine is cranking.

[jleilich]

I would focus on the flaky MAP signal. That should be easiest to trouble-shoot. Once you find/fix the problem there, everything else might get "healed" too. First, connect a simple vacuum gauge to the intake. Let's see if the MAP really is going terribly low. Like others, I doubt it, but it is so easy to check. Assuming the manifold vacuum is low (MAP high) during cranking, then we move on to electrical tests with voltmeter. Sensor 5V to sensor ground, sensor ground to chassis/MS ground, sensor signal to sensor ground; all those while the engine is cranking.

All great suggestions thanks, Hope to hit it hard this weekend.

[jleilich]

I ran some more tests in test mode and Its doing some funny stuff. Its seems that only Inj A is working properly. I was pretty sure they all worked properly in the past and have tested them all in the past. I bench tested a few injectors and they all seem to operate properly.

Here is the result of test mode testing:
Test mode

Injector test mode
output int: 50.0
Inje test mode: One
Inj Channel Inj: B through H
Pulsewidth 50
# on inj: 1000

Result: No clicking, no light. Pulse gauge reads like its working

Inj Channel Inj A.
A lights solid (noid light), does not pulse. (bright)


Inj Test Mode: Sequence
Inj Channel A-H

Only A fires, pulses

Inj test mode: All
A lights solid


So what would cause only injector A to work?

[grom_e30]

i would be looking at the simple things first, ms3x db37 cable not connected properly, the ribbon cables between the ms3 and ms3x card, and possibly the ground cables for the ms3x card.

it would seem unlikely that its a hardware failure and that 7 out of your 8 drivers have failed.

[jleilich]

Just to do an experiment. Could I wire the injectors off of the MS3 card and just run INJ Bank 1 and INJ Bank 2?

I see there are 2 wires for each. Would I just split them up between the injectors?

Inj Bank 1 to Cyl 1 and 3, the other Inj bank 1 to 5 and 7. and the same on the other side
Inj Bank 2 to Cyl 2 and 4, the other inj bank 2 to 6 and 8??

Then just change fuel outputs to Std fuel?

would I need to change anything else? I need this thing running by next thursday we are taking it to a weekend car show and my wife will be pissed if its not running

[grom_e30]

yeah you could wire your injectors to the main board inj1 & inj2 channels and run it in batch mode. you will need to change to 'std fuel' and turn sequential off and set the injector staging and squirts per cycle all these are found under 'engine and sequential setting'

id use test mode to confirm these outputs work first before making any wiring changes though. Another thought you could try reloading the firmware on the ecu to see if that helps before you make any changes i'm not convinced it will help but may be worth a shot.

[jleilich]

IT RUNS!!!!!!!

you guys will never guess WTF was wrong. We all thought it would be something stupid and it was.

Had remembered at one point that the injectors cycled properly at one point but didnt remember when that stopped happening. I started going backwards. I had swapped relays, and did some other things. Then I had an idea, all i did was swap the 5A fuses I was using for the injectors for 15A fuses. Soon as I flipped my toggle switch I heard the prime cycle. Turned the key and it fired.

So either the 5A wasnt enough or those 5A fuses were shot. They are non see though so I couldnt see if they were bad and had no reason think other wise. I was running 5A fuses for my injectors. Based on what the diagram for the MS3 said. What size fuses do you guys use for injectors?

anyhow, thanks for your help guys. I'm going to get this thing drive able this week so we can take it down to the show in a few weeks. Hopefully there wont be any new surprises.

[grom_e30]

glad you got it sorted, 8 injectors powered off the same feed? if so id go 10-15 amp fuse wise

[jleilich]

glad you got it sorted, 8 injectors powered off the same feed? if so id go 10-15 amp fuse wise

I have them split between two fuses, Bank A and B. Both fuses were crap