hockdane

iTrader: (3)

i have spark i have fuel pressure and the car will fire up when i give it a shot of starter fluid, but will not start on it's own. i have 12 volts at the injectors with the key on and i have already replaced the ignition modual in fear that it may be the reason, it was not, so does anyone have any insight as to what else i can try. the car was running be for i did the motor swap and now that the new motor is in it will not run. i am also using a FAST stand alone system.

jv9999

iTrader: (1)

Neither bank fires? Is this a VATS (security) equipped car?

ljnowell

tpi?

aceez71

iTrader: (1)

Buy yourself a noid test kit. It will blink as you turn the engine over this verifies the ign reference pulses are there and the ecm is pulsing the ground to injectors. It is in the gm manual. Also if vats wasnt removed from the chip (89 and up) this will cause the same problem as per the message before.
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Also did you reconnect the engine grounds (harness) during the engine swap

hockdane

iTrader: (3)

it is a 89 so i am thinking it will have VATS and it is a tpi car. how do i get rid of VATS or fix it?
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i am pretty sure i reconected all the grounds as well

87zjeff

iTrader: (4)

i'm pretty sure if it is vats related, then the starter will not crank either.

jv9999

iTrader: (1)

Jeff's right, so it's probably not a VATS problem. Since the two banks are separate all the way to the ECM, I'd suspect the pick-up coil (in the the dist) as the ECM needs that signal to fire the injectors.

ljnowell

Second the pick up or ground problem.

hockdane

iTrader: (3)

all the grounds are good that i know of. all the ones on the back of the head. as for the pick up coil would the car still spark if that was bad i also have a msd dist as well

hockdane

iTrader: (3)

bump

Dyno Don

iTrader: (7)

I don't know about the FAST system, would it use VATS?

I always test the injectors before installing them after sitting. The old fuel dries up and prevents them from working.

I agree on the noid light setup, it's the only way we know if the injectors are getting pulse.

hockdane

iTrader: (3)

i will try the noid lights, may be then i can see what kind of power your headers make.

hockdane

iTrader: (3)

i tested mwith the noid lights and still no luck, is there any other grounds that i could be missing or an other reason why the injectors will not fire.

aceez71

iTrader: (1)

After reviewing your first post i reviewed my gm service manual. If you have spark the ign system is sending reference pulses. The ecm or in this case possible code in your chip is not allowing the ecm to pulse the grounds in Ckts 467 and 468 . As you stated the injector harness has 12 vdc so your missing the neg pulses or pulsed grounds. Have you disconnected all the injectors and verified at least 10 ohms or more per ea. injector as per the service manual a short here would pull the entire ckt down however it would take at least one on each bank Not likely. Also you can probe ckts 467 and 468 from D15 and D16 of the ecm connector to the injector harness Lt. Blu 467 (D15) and Lt. Grn 468 (D16) and make sure they are NOT shorted to ground if so find short and repair. If not I would probe D15 with one lead and the other lead to any injector plug lt blu on the 1,3,5,7 bank. And repeat for ckt 468 (D16) to Lt. Grn this time you should have continuity (a dead short) since you are reading one end of the wire to the other. This is assuming your custom harness used standard GM color code. As fas as VATS, in my S10 im running an 89 chip with VATS disabled so im not certain but im pretty sure it would turn over but the ecm would not allow the injectors to fire. My other TPI is an 87 Camaro so it doesnt have VATS. Any meter that has a contunity check or resistance setting will work digital or analog Hope this info helps!

Dokken10

iTrader: (18)

VATS was started in late 88. VATS enables or disables the fuel pump and the starter. Since your getting fuel pressure and it cranks, its NOT your VATS. I had this problem on a 91 Formula 305 TPI last summer. I spent many hours reading and troubleshooting and still could not get it to run without a shot of starter fluid. I walked away from it for about a month. The car had been sitting for awhile without running and one day it hit me that maybe the injectors were stuck. I gave the injectors a tap and then it started right up. Even though the fix was simple I did learn alot about how a TPI and VATS work and how to troubleshoot them.

hockdane

iTrader: (3)

i still have not found the source of my problem. anyone else want to take a shot at it?

hockdane

iTrader: (3)

if i have a bad pick up in the distributer will it still spark? and will that cause the injectors not to fire.