first turbo fail start. need help, diypnp
 

starting up the miata after a turbo install. first starts were fails

94 miata, 550cc rx7 turbo injectors, vishnu dual feed rail with pressure (gauge reads about 42 psi during cranking), diy turbo kit with pieces from begi. LC-1 WBO2 and DIYPNP from Braineack


checked the plugs and i'm getting fuel to 1 and 3, but not 2 and 4.

the car sounds like it wants to start, but dies out, almost like a vac leak, but I can't find any vac leaks for the life of me

any help would be great. I'm hoping it's not anything with my brain diypnp not controlling injectors 2 and 4 or something. injectors were cleaned by witchhunter, however I've had them sealed for longer than the recommended 1 month

haven't checked for spark yet, but doing that now
EDIT: Spark on all 4 cylinders

is there anything I need to look out for in the CAS? I have it in the middle at the moment

so I've taken an ohmeter to the injectors with the clips off and they all show 12.5 ohms, which is good i'm assuming since they're pnp high impedance.

grounds have all been cleaned with sandpaper, etc

i think i've recreated the project probably about 4 times just to make sure i haven't forgotten anything to no avail.

tried turning on Bank 2 of injectors on in tunerstudio. no difference, although it shouldn't have from what i've been reading, plus i'm not sequential anyway

pretty much everything on this car fuel wise has been changed. walbro 190hp, new fuel filter, fuel rail, injectors have been changed. running stock fuel regulator.

Bump for a local, and moved to the MS section.

Like I said on CR.net, double check MAP, MAT, and coolant temperatures, making sure one is not off. Make sure fuel pump turns on when the MS first powers up, post a log of you trying to start it, post your .msq, and we'll see what we can do.

Use injector test mode to see if you can pulse each injector bank.

If your injector 2&4 bank does not fire, you can test the output with a scope (preferred) or noid light. Another check is you can put all injectors on a single bank and see if anything changes.

If the injectors are just stuck, remove them from the motor and clamp them (use only moderate force) in a bench vice. Add a shot of WD40 or similar in the top of the injector, then proceed to beat the crap out of the bench vice with a hammer for 5 to 10 minutes. That should free them up.

If 2 & 4 aren't firing that could be something wrong with the output driver as those would be batched if not running seq fuel. Use the output test mode (right most dropdown) and check both A and B inj outputs and make sure they really are/are not working, then we can go from there.

EDIT: looks like this has been user error the whole time :P I ordered the DIYPNP so long ago, I forgot what I had asked Brain to put in the MS. I have the sequential injection module! lol. wow... this explains a lot

looks like my 2 and 4 injectors aren't responding when I try to pulse them using the output test modes.

However, since 2 and 4 are supposed to be batched, when I switch between Inj1 test channel, and Inj2 test channels, if I have Injectors 1 and 3 plugged in, it sounds like Injector#1 corresponds to Inj1 channel, and Injector#3 corresponds to Inj2 channel. Is something wrong?

Other thing is, from Witchhunter, they say to check if injectors are stuck with a 9v, and I've done that and they all make an audible click. But pulsing with the megasquirt seems like the injectors are stuck, or maybe a signal is mixed up

Ignore the injectors for now, either modify your injector harness to run sequential, or modify your MS to run batch, if it still doesn't work, I still won't blame the injectors until I have you try a bunch of other stuff, locked injectors are fairly rare. Especially if they've been cleaned. My injectors weren't flowing very evenly, but after spending 20 years laying around either in a rx-7 or not, they still worked enough to start the car.

Injectors get stuck, it's not that uncommon. I've unstuck at least 3 sets this year.

Did you run injector test mode yet?

Firing order 1 3 4 2
So injector 4 is C and 2 is D.

He had Seq. inj module, but for some reason his map didn't have the drivers turned on. I sent him a new msq to try.

thx brain for all your help. I will try this. hopefully this fixes it

so it looks like i had two problems. injectors AND the megasquirt. somehow it wasn't setup for sequential at first. with the map brain sent me, in test mode, I could select injectors 2 and 4 (channels 3 and 4), which do not make any sound compared to injectors 1 and 3 (channels 1 and 2). I'm going to try my stock injectors or move around the injectors to double check if it really is 2 stuck injectors. thanks everyone!

EDIT: so sequential works!!!! only with the stock fuel injectors though :P looks like witchhunter is going to get some more bizzznesss

question, if I start up the car with stock injectors to do timing, i only need to change the REQ FUEL right? engine displacement 1839cc, 195500-2180 injectors (254cc), calculator is giving me a REQ FUEL of 12.2, sound about right?

correct.

You should be able to unstick the injectors in 10 minutes using my patented method posted earlier.

Heh, looks look I'll try that out later today. Gotta get me a new vice since the old one died while making my intercooler brackets and license plate bracket. my trusty chinese vice had taken so much abuse :giggle:

Sooooooooooo, got the car working :)

Thanks Ben for the recommendation on getting the injectors unstuck, worked out fine it seems and my injectors rx7-550's are up and running

now I gotta sort out idle problems, as I it keeps oscillating, my a/f ratios during idle get to like 20, which freaks me out... not sure if that's normal at idle....

tried changing my req fuel to a higher number. with 1839cc engine displacement, 550cc injectors, I get 5.5 as my normal number, but the car won't even try to stop oscillating until i put 5.8 in. anything lower and the car eventually dies out

I've checked my timing with a timing light and it's exactly at 10 BTDC when "use table" is selected, but when I try to do the "fixed timing" setting to force it to stay at 10, the car dies out (as advised in the diypnp setup article from braineack)

Shouldn't it be -10? It's been a while.

I've always referred to it as 10 BTDC, before top dead center. or people refer to it as -10 tdc right?

anyway, I have two markings on my crank, one of them corresponds to my 10, and the other to TDC as per miata.net timing directions

question: what map sensor does Braineack's DIYPNP usually use? it's the 250kpa one. on my map, when I go to it, it says custom. Should I be using the Custom setting? or the MPX4250 setting?

Everything thing is written and spoken as 10* BTDC, including what the marks show above the crank, 10-14* or whatever. My point is that when you're setting your timing, you need to type "-10" into the static timing box, not "10".

I could be completely wrong, but it would throw your readings off quite a bit.

in tunerstudio, when I do the "fixed timing" option compared to "use map" setting, it's like doing the -10 and 10 in megatune. When i'm in "use map" mode, it idles with oscillation, but when it oscillates down, it pretty much dies. When I set it to "fixed timing" mode, it dies right away with a "Timing for Fixed Advance(degrees) of 10"

I understand what you're saying in megatune, and the setting from 10 to -10 for making sure my car stays in a fixed timing mode to check the timing. thing is... unfortunately I can't check the timing in fixed timing mode as the car dies. I can barely check it in the normal, non-fixed mode

I hope i'm not getting our terms mixed up since I'm trying to look up megatune stuff and corresponding tunerstudio settings. In the megatune directions, it says my timing should be reading 15-18 in non fixed mode.... could my timing just be way retarded right now as my timing in NON fixed angle is exactly 10...