whoever figures this out is god! injectors not firing - Third Generation F-Body Message Boards

pearlphoenix · 08-30-2009, 03:39 AM

ok heres the story, recently did an engine swap to a 383 HSR, everything is hooked up and ready to run and car wont start. it an 86 trans am, non VATS car. the car turns over freely and will run if i mist gas or starter fluid through throttle body. i took the top part off the hsr and crank the motor looking through intake ports at injector boss and see no gas from any of the injectors. i hooked a seperate 12volt source up to injector and it sprays normal as it should. the injectors plugs have power and i hooked up the lighbulb to the clip and it flashes. i relooked at all my harness grounds and all are accounted for and hooked up to a good ground. my ecm flashed code 12 and tried a diff ecu and still nothing. all injectors ohm are the same. i also checked the fuses and there fine too. i am totally stumped!!

please someone have something thanks in advance

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tom86iroc · 08-30-2009, 04:24 AM

can you hook up a volt meter to an injector and tell me what the volts are when cranking??is the computer 86 as well or a different year?

Viprklr · 08-30-2009, 08:34 AM

Are you getting gas to your rail?
What's your fuel pressure?

pearlphoenix · 08-30-2009, 11:22 AM

Quote:

Originally Posted by tom86iroc

is the computer 86 as well or a different year?

yes it hasnt been messed with since before the swap

pearlphoenix · 08-30-2009, 11:23 AM

Quote:

Originally Posted by Viprklr

Are you getting gas to your rail?
What's your fuel pressure?

yes, got 45psi in the rail

pearlphoenix · 08-30-2009, 11:24 AM

Quote:

Originally Posted by tom86iroc

can you hook up a volt meter to an injector and tell me what the volts are when cranking??

any easy way to do this? i hooked it up to the injector clip but it pulses too fast to get a reading

transam85dudeman · 08-30-2009, 11:46 AM

the Ground was my first idea..it could be a bad sensor that controls the injection pulse like the pickup coil in dizzy under ignition control module. or perhaps a disconnected tps sensor. it has to do with crappy reference signal to computer in order to fire the injeector? thats just what i think. what size injectors. did you get a new chip. gotta get a chip

pearlphoenix · 08-30-2009, 11:50 AM

Quote:

Originally Posted by transam85dudeman

it could be a bad sensor that controls the injection pulse like the pickup coil in dizzy under ignition control module. or perhaps a disconnected tps sensor. it has to do with crappy reference signal to computer in order to fire the injeector? thats just what i think.

im running 30lb injectors, what is this sensor under the control module?? do tell more? is this controlled by the 4 wire connector to the dizzy or???

transam85dudeman · 08-30-2009, 12:02 PM

http://answers.yahoo.com/question/in...0054951AAoxZQQ "Pick-up coils send an electrical signal to the ignition module to trigger spark and fuel injectors. /Sends signal to the ignition module for spark,also to the engine computer for pulsing fuel injectors." thats what i read. my pickup coil took a dump on me once. the permenant magnet broke 6 spots. ill take a pic of it. there. see how the magnet was broken and the coil was fryed. when the magnet breaks. they become there own magnets and repel

transam85dudeman · 08-30-2009, 12:47 PM

IF it is bad? to replace you got to remove the dizzy cap, mark the two rotor positions or just turn the crank clockwise until tdc. remove the hold down clamp. remove the dizzy, next punch out the roll pin (recommed a new roll pin but id didnt bother with spending the dollar) and remove the dizzy gear, shims, (i had to add shims, my dizzy had a endplay of .060" i shimed to the endplay was 0.008") and remove the shaft., remove the module, condesor, pop out the c-clip and the ground screw and bam replace the pickup coil and and reverse the step to install. but use the module thermogrease under the module or itd burn up.. should start then. if not, advance the dizzy or retard until you can time it.

pearlphoenix · 08-30-2009, 01:01 PM

yeah i just ripped into my dizzy and its not broken everything looks fine....i was really hoping that was it....i have the small cap dizzy but still had the magnet just easier to see

transam85dudeman · 08-30-2009, 01:07 PM

test the ohms

tom86iroc · 08-30-2009, 02:59 PM

here try this

pearlphoenix · 08-30-2009, 06:42 PM

well after one hell of a weekend, i finally figured out what the problem was......after dude man had me lookin at the dizzy, i noticed that my oil pressure sensor connector was just sitting on top but not actually pressed on....i would have probably never made the connection with oil pressure sensor and no injectors firing but thats my luck....thanks everyone for your help its much appreciated

tom86iroc · 08-30-2009, 07:50 PM

your welcome glad ya got it runnin

Glenno · 08-30-2009, 09:57 PM

Quote:

Originally Posted by pearlphoenix

well after one hell of a weekend, i finally figured out what the problem was......after dude man had me lookin at the dizzy, i noticed that my oil pressure sensor connector was just sitting on top but not actually pressed on....i would have probably never made the connection with oil pressure sensor and no injectors firing but thats my luck....thanks everyone for your help its much appreciated

Wow, nice ending. Learned a lot!

pearlphoenix · 08-30-2009, 10:31 PM

Quote:

Originally Posted by Glenno

Wow, nice ending. Learned a lot!

yep and the worst part is i remember reading a few years back about how our cars would shut down under low oil pressure and i thought that was kinda neat

. i would have assumed spark before injectors anyhow though

transam85dudeman · 08-30-2009, 10:44 PM

how does she run? fast? im going to invest in a bare block and build it up. put a bad *** super charger on it. drop it in a 74' trans am

pearlphoenix · 08-31-2009, 05:27 PM

Quote:

Originally Posted by transam85dudeman

how does she run? fast? im going to invest in a bare block and build it up. put a bad *** super charger on it. drop it in a 74' trans am

well i was actually surprised at how well it idled with the stock chip right at about 950rpm and sounded nice and lopey like i was hoping, i havent really got on it yet for 2 reasons, 1 my starter took a sh*t from all the abuse this weekend, and 2 i dont really wanna get on it til i get the chip installed make sure it sounds right before some hard pulls.

transam85dudeman · 09-01-2009, 12:51 AM

Quote:

Originally Posted by pearlphoenix

well i was actually surprised at how well it idled with the stock chip right at about 950rpm and sounded nice and lopey like i was hoping, i havent really got on it yet for 2 reasons, 1 my starter took a sh*t from all the abuse this weekend, and 2 i dont really wanna get on it til i get the chip installed make sure it sounds right before some hard pulls.

wow wee wow. hmm, who you going through for chip? i recommend a/c delco starter. no shims required. maybe a skull shiftknob