Inj Bank 1 & 2 inconsistency help please...

hobieboy · Post by **hobieboy** » Sun Aug 13, 2006 6:14 am

Hi,
A bit of background first: MS-I v3 board, 29q2 code. 6 cylinders and injector set to alternate, 2 squirts. Injectors were new & flow matched. Common fuel rail across the 2 banks.

Have been trying to get the car to idle but she starts very well (usually ~2 cranks), stays running for ~5 seconds then die. When running, my MAP shows ~70kpa which seems high.

Now the question/help needed - I finally decided to pull the plugs and take a look. The left bank looks to be perfect - a bit black in the center and dry. The right bank - the entire injector is black and wet.

So, this lets me to think of dead injector driver for 1 side? But... car will NOT start if only 3 cylinders are running. I'll do the LED test later today.

BUT... can it somehow be that the injectors on the left bank is not fully opened so the entire side getting inconsistent fueling? How could I verify this?

thanks.

jsmcortina · Post by **jsmcortina** » Sun Aug 13, 2006 6:37 am

Check the injector driver components and flyback on the circuit board. If one channel has different flyback then I would expect the injectors to behave differently.

If these are hi-Z then the megamanual says that you can connect all six to one channel (for testing.)

James

hobieboy · Post by **hobieboy** » Sun Aug 13, 2006 8:10 am

James,
Sorry for being slow

How could I check flyback? What kind of voltage/pulse should I expect & where to tap into?

thanks.

jsmcortina · Post by **jsmcortina** » Sun Aug 13, 2006 8:33 am

Do a visual inspection first, make sure the big diodes are in the correct direction and are soldered well.

James

hobieboy · Post by **hobieboy** » Sun Aug 13, 2006 9:42 am

ok - did the visual inspection and everything looks good.
I also noticed that the log also shows flyback from the portA status occassionally. What does that mean? I have included one of the logs as reference.

Any suggestion where to look & what to do next?

thanks.

hobieboy · Post by **hobieboy** » Sun Aug 13, 2006 6:04 pm

I scoped the flyback circuit during cranking and they both appear to be working correclty and returned the same waveform. Voltage was clamped ~36V.

Just to prove that its not the rest of the fuel delivery components, would it cause any problem if I swap the power connector between the 2 banks of injectors so that bank 1 becomes bank 2 & vice versa?

thanks...

chrispel · Post by **chrispel** » Sun Aug 13, 2006 6:16 pm

Check your coils maybe one is bad causing them not to fire right.

tbitz · Post by **tbitz** » Sun Aug 13, 2006 8:20 pm

Swap the injector driver from left to right bank and see if the problem follows the change. Do this at your injector wire harness not in the MS unit.

This will help narrow problem to MS <--> injectors, ignition.