will injectors still pulse w/bad cam sensor? (no start problem)

[mxmstrmel]

I have quite a dilemma. When I try to start my car, all 6 plugs are sparking and the injectors are pulsing, but it just won't start. I tried swapping ECMs.... nothing. I tried readjusting the cam sensor.... nothing. It doesn't seem to be getting fuel (spark plugs are dry).

There is fuel in the rail. Pressure is at around 40-42 psi and it remains there for about 10-15 minutes.

If I spray some carb cleaner, it starts right up and runs fine (a little hesitation here and there).

Scanmaster is reading RPMs. I've searched the archives and tried just about everything. Of course that didn't help because most people either don't have spark or don't have an injector pulse. I have both.

I was just wondering if the injectors would still pulse if the cam sensor was going to s.... Does anyone have any suggestions?

Mel

 

[S10xGN]

I believe it does still pulse the injectors - just at the wrong "time" if misadjusted... You say your injectors are pulsing and you have fuel rail pressure, yet no start - something's wrong here. How are you verifying injector pulse?

 

[sweetv6]

go down to gnttype.org

http://www.gnttype.org/techarea/maintenance/nostart.html

hope it help

Claude

 

[bruce]

http://www.t6p.com/forums/showthread.php?t=3626

 

[mxmstrmel]

Originally posted by S10xGN
I believe it does still pulse the injectors - just at the wrong "time" if misadjusted... You say your injectors are pulsing and you have fuel rail pressure, yet no start - something's wrong here. How are you verifying injector pulse?

I connected a noid light and verified the injectors were pulsing (light was flashing). As for the plugs, I pulled all 6 plugs and verified spark while cranking. I'll say it again..... ALL 6 PLUGS WERE SPARKING AND THE INJECTORS WERE PULSING (FLASHING) w/ FUEL IN THE RAILS....

any ideas...?

 

[Razor]

I had a buddy this happened to and his problem ended up being his fuel pressure was set too high. Like 55 PSI. His guage was bad.

If the injectors were firing, then you'd have fuel in the cylinders rite?

And you say you have spark. Plus you mentioned adding fuel to the motor made it run. So obviously the coil pack/ignition module are doing theyre jobs.

Look at fuel pressure or injector problem?

 

[ijames]

If all plugs and all injectors are firing, with fuel in the fuel rail, and it will only run when you spray carb cleaner, then the fuel in the rail must not be getting to the cylinders. Either your chip is for injectors that are much bigger than yours actually are, or the injectors are plugged up somehow. What size injectors do you have? What have you changed since the last time it ran okay? Has the car been stored for a long time? If you changed chips but not injectors, change back or maybe try removing the chip if your injectors are 50's or smaller and crank it with just the little chip in the ecm. That will make the check engine light blink very rapidly to let you know the eprom is bad (missing) and will put it in back up fuel mode which will be very rich with 50's and way way too rich with any bigger injectors but it should crank up just to let you know the injectors are okay.

 

[mxmstrmel]

I'll check the fuel pressure again tomorrow and update you guys on the car.

Thanks for all the replies!

Mel

 

[Otto J]

I just ran into an identical problem with a tuneport firebird, had injector pulse spark and everything but wouldnt fire if you didnt spray something down the intake.
Do yourself a favor and unplug all the injectors, one at a time using on OHM meter check the resistance of each one, they should be in the 15.0 to 17.0 range
WE had 6 injecotrs on his car that ohm at 2.2-4.3 ,These werer high mileages tock injecotrs
Swap injectors car starts and runs better than it has in the last year

 

[mxmstrmel]

Originally posted by Razor
I had a buddy this happened to and his problem ended up being his fuel pressure was set too high. Like 55 PSI. His guage was bad.

If the injectors were firing, then you'd have fuel in the cylinders rite?

And you say you have spark. Plus you mentioned adding fuel to the motor made it run. So obviously the coil pack/ignition module are doing theyre jobs.

Look at fuel pressure or injector problem?

RAZOR KNOWS ALL

Check this out... FP was at around 45#. I go to turn it down 1#, and it shoots up to 60#. After I turn it WAY back down to 45, it starts right up. I think its time for a new gauge and/or regulator.

Thanks for all the help

Mel