injector bank #2 and fuel pump ground

[christiondavid]

hello i have a question maybe 2, i built a ms2 v3 that i purchased from diy, i have a couple of things going on with it and i hope someone can help me make sence of it, one of my issues is with the injector banks on the megastim took the daughter card off and grounded 21 and 22 bank 1 lit up and then 2 lit up so i guess i passed the test but when i fire up the ms2 on the car bank 1 in test mode works fine bank 2 will not work at all, but if i use my multimeter on continuity and run the test both banks seam to work fine pulsating beeps but if i plug the injectors in wont work at all that's bank 2, now my next issue could have something to do with the injector bank and that's my fuel pump light on the stim wont turn off and with daughter card off light stayed on and also when i had it on the car would not ground the relay to turn on the fuel pump relay could the fuel pump problem affect my injector bank 2 ? any help would be great thank you.

[DaveEFI]

If the pump LED on the stim stays on with the daughter card unplugged, you have (likely) a short in the pump driver. Check for a solder bridge at Q2&19 and that D4 isn't short circuit.
Haven't come across anything which could be common to that and Inj 2.

Inj 1&2 are identical, so with them in the same state (on or off) compare voltages on all the transistors, etc. But start by checking Q9 &12 have their tab insulated from the heatsink. With it powered off, you should get the same resistance reading at both. A short there should be obvious.

[christiondavid]

Thank you i will check those and get back to you and thank you.

[christiondavid]

If the pump LED on the stim stays on with the daughter card unplugged, you have (likely) a short in the pump driver. Check for a solder bridge at Q2&19 and that D4 isn't short circuit.
Haven't come across anything which could be common to that and Inj 2.

Inj 1&2 are identical, so with them in the same state (on or off) compare voltages on all the transistors, etc. But start by checking Q9 &12 have their tab insulated from the heatsink. With it powered off, you should get the same resistance reading at both. A short there should be obvious.

ok starting with q9 looking at the letters tip 125 starting left to right with power on I get 13.7 left pin 13.7 middle pin and 13.7 right pin and q12 left pin 12.8 middle pin 13.6 right pin 5.9 as for q2 and q19 and d4 how would I go abought checking those with my multimeter thank again.

[christiondavid]

If the pump LED on the stim stays on with the daughter card unplugged, you have (likely) a short in the pump driver. Check for a solder bridge at Q2&19 and that D4 isn't short circuit.
Haven't come across anything which could be common to that and Inj 2.

Inj 1&2 are identical, so with them in the same state (on or off) compare voltages on all the transistors, etc. But start by checking Q9 &12 have their tab insulated from the heatsink. With it powered off, you should get the same resistance reading at both. A short there should be obvious.

ok starting with q9 looking at the letters tip 125 starting left to right with power on I get 13.7 left pin 13.7 middle pin and 13.7 right pin and q12 left pin 12.8 middle pin 13.6 right pin 5.9 as for q2 and q19 and d4 how would I go abought checking those with my multimeter thank again.

q9 and q12 are insulated

[christiondavid]

ok so pushed on until I get some feed back on those problems, but iam glad to say I did fire up my sons Honda k24a4 EF using my ms2 v3 in wasted spark 36-1 wheel and a 3 wire cherry hall sensor I ran all the injectors of 1 bank but she fired and ran I could not keep it running to long as the car sits has no radiator, but I did post up top my redings that I took for the injectors any help would be great thanks again.

[DaveEFI]

I'd stick to one fault at time until that is sorted. The fuel pump relay driver is a simple circuit, so sort that first.

[christiondavid]

Yes i think i will start with the fuel pump problem first but first let me say i was testing on the jimstim and fuelp pump on with no rpm and with rpm fuel pump light turns off?

[DaveEFI]

The pump driver is controlled by the processor With base code loaded, your Stim at zero RPM (engine stopped) should show the pump LED on for a second or so when you power up (priming) then go out with no RPM. As soon as the processor sees RPM (engine cranking or running) from the Stim, it should be on.

Q9 having the same voltage on every pin means something is wrong there. (A transistor normally has a 0.6v voltage drop even when turned hard on, as you see with Q12) so it looks like it is faulty. They are very cheap to buy, so get a spare or two.

Cut the legs to the old when removing, as there is less chance of damage to the PCB desoldering them one by one.

[christiondavid]

Thank you for the quick reply I will have to order that part

[christiondavid]

Question for q9 can I use a tip 122 instead of the tip 125 it calls for? Thanks I do have plenty 122 but no 125

[christiondavid]

Replaced it with a tip 125 now I have to bring it to the car and test that bank

[retired]

Question for q9 can I use a tip 122 instead of the tip 125 it calls for? Thanks I do have plenty 122 but no 125

NO, absolutely no.

The 122 and 125 are complementary NPN/PNP pairs.

They are equal but opposite to each other, one flows current one way, the other the opposite way.

EDIT,
http://www.st.com/content/ccc/resource/ ... 000911.pdf

[christiondavid]

Thanks i did install the correct tip 125

[christiondavid]

Replaced q9 with no change now on the jimstim everythin seams to be working as it should lights turn on for both injector banks blink through all rpms at the jimstim i take one of my injectors and run one side to injector bank 2 and touch the positive with the other end of the injector to positive with and with out rpm the injector clicks on and off when i touch positive just seams like injector injector is stuck on ground, and in the mean time with my fuel pump output problem, on the stim with no rpm the fuel pump light is on and with rpm light turns off like its working backwards this thing has me going crazy, i did notice that at d7 band side 5v give or take 3.5v other side and d5 3.5 non banded side 12v banded side any thoughts would be great help thank you guys.

[DaveEFI]

Set the stim to zero RPM. Does the pump LED come on for a second or so at switch on, then go out?

[christiondavid]

On stim with all settings set to off light comes on stays on untill i start to give it rpm then the light turns off so with no rpm light on with rpm pump light turns off.

[DaveEFI]

On stim with all settings set to off light comes on stays on untill i start to give it rpm then the light turns off so with no rpm light on with rpm pump light turns off.

Unplug the daughter card and power the MS up via the Stim. Is the pump light on or off?

If off and does as you say with the daughter card plugged back in, I'd first reload the firmware.

[christiondavid]

ok so I just took the daughter card out and all the lights are off at the stim even the pump light no injector light no fuel pump light with or with out rpm and with the daughter card in the fuel pump light comes on and when I give it rpm light turns of and the injector light work as they should but injector bank #2 seams like its stuck on ground.

[christiondavid]

download firmware again stayed the same