NO FUEL FROM INJECTORS...no start

WyoSyclone

WyoSyclone

Active member
Re: NO FUEL FROM INJECTORS...no start

Syclone#2960 said:
OHMed out a known good injector it matched the installed injector.
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I really dont' think you need to be looking at injectors.... if you heard sizzling from around the distributor area I'd zero in on that. Check the coil and coil wire.
 
BoostedSUV

BoostedSUV

Active member
Re: NO FUEL FROM INJECTORS...no start

I'd go with ignition module... May want to just change out the whole dist just in case.
 
BoostedSUV

BoostedSUV

Active member
Re: NO FUEL FROM INJECTORS...no start

If you heard a pop while driving that was more than likely an ignition back fire. Check the obvious first, make sure everything is still plugged into the back of dist and into coil. You could take the cap off, crank the motor and make sure the rotor is still turning. If yes to all go with ign module or the coil pick up....
 
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S

Sy+Ty

New member
Re: NO FUEL FROM INJECTORS...no start

+1 on the ignition backfire. You've been seeing adequate FP at the rail the whole time. Got voltage at the injector(s). Would seem that fuel is not your problem. BTW, IDC s/b zero w/ key on but motor not running as injectors obviously aren't firing at this point.

Since you've swapped in a known good ign. module, bypassed MSD box to rule that out, verified voltage at the coil etc. Only thing left IGN-wise is coil wire (as prev. mentioned), wiring harness/connectors at distributor & pick-up coil inside distrib. I suspect you would've noticed any issue w/ rotor tip etc. when you changed out the ign. module.

Don't know how to check p/u coil, but there's gotta be a way. May want to research that before pulling the distributor apart. Or maybe easier to swap in a known good spare distributor as prev. suggested.

Just typing outloud as most of this has been pointed out in separate posts... These type of gremlins suck. Nice as always to see the helpful replies. Keep us posted b/c we can all learn from this type of troubleshooting. ;-)
 
Syclone#2960

Syclone#2960

What ever it takes!!
Re: NO FUEL FROM INJECTORS...no start

Sy+Ty said:
+1 on the ignition backfire. You've been seeing adequate FP at the rail the whole time. Got voltage at the injector(s). Would seem that fuel is not your problem. BTW, IDC s/b zero w/ key on but motor not running as injectors obviously aren't firing at this point.

Since you've swapped in a known good ign. module, bypassed MSD box to rule that out, verified voltage at the coil etc. Only thing left IGN-wise is coil wire (as prev. mentioned), wiring harness/connectors at distributor & pick-up coil inside distrib. I suspect you would've noticed any issue w/ rotor tip etc. when you changed out the ign. module.

Don't know how to check p/u coil, but there's gotta be a way. May want to research that before pulling the distributor apart. Or maybe easier to swap in a known good spare distributor as prev. suggested.

Just typing outloud as most of this has been pointed out in separate posts... These type of gremlins suck. Nice as always to see the helpful replies. Keep us posted b/c we can all learn from this type of troubleshooting. ;-)
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The coil wire? You mean the short 8mm taylor wire from the ignition coil to the distributor cap? That checked out OK on the syclone.
Going to swap out distributor tonight (I hope).
 
SY2932

SY2932

Administrator
Re: NO FUEL FROM INJECTORS...no start

He's referring to the pick up coil wire under the distributor cap. Disconnect the plug and measure the resistance between the white and green wires. It should be between 500 and 1500 ohms. It is important to note that whatever the value is, it should NOT change when you move or flex the wires. If it does, that's your smoking gun...
 
Syclone#2960

Syclone#2960

What ever it takes!!
Re: NO FUEL FROM INJECTORS...no start

SY2932 said:
He's referring to the pick up coil wire under the distributor cap. Disconnect the plug and measure the resistance between the white and green wires. It should be between 500 and 1500 ohms. It is important to note that whatever the value is, it should NOT change when you move or flex the wires. If it does, that's your smoking gun...
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I checked it & its getting 797-804 OHMs with the battery charger plugged in. Without the charger plugged in its steady at 804 ohms. The other 2 spare distributors I have are reading a steady 798 & 845.
 
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BoostedSUV

BoostedSUV

Active member
Re: NO FUEL FROM INJECTORS...no start

did you try another dist? I believe the ign module controls injector pulse
 
Big Mike

Big Mike

New member
Re: NO FUEL FROM INJECTORS...no start

Do our trucks need oil pressure to fire the injectors like some of the other GM cars out there? Maybe a bad oil pressure switch. What about that fuel pump again maybe you have pressure but not volume. If it was any ignition part it would not fire when using starting fluid. What about the injector drivers on the computer? Did you swap out the computer yet?
 
WyoSyclone

WyoSyclone

Active member
Re: NO FUEL FROM INJECTORS...no start

Big Mike said:
Do our trucks need oil pressure to fire the injectors like some of the other GM cars out there? Maybe a bad oil pressure switch.
Click to expand...

Nope, the voltage coming from the oil pressure switch acts as a backup supply to the fuel pump if the pump relay goes south.
 
Syclone#2960

Syclone#2960

What ever it takes!!
Re: NO FUEL FROM INJECTORS...no start

Installed another ECM & distributor with another Control Module (nothing changed). I have oil psi when cranking.

Sprayed more starting fluid to verify everything installed worked (it ignitied for a second).
 
WyoSyclone

WyoSyclone

Active member
Re: NO FUEL FROM INJECTORS...no start

How many miles on the motor? I wonder if you could have jumped a tooth or two on the timing chain? It's a long shot.....if you heard that sizzling up by the distributor that's a clue.... are all of your grounds good (left front of intake manifold, rear of left cylinder head, battery ground)??
 
BoostedSUV

BoostedSUV

Active member
Re: NO FUEL FROM INJECTORS...no start

WyoSyclone said:
How many miles on the motor? I wonder if you could have jumped a tooth or two on the timing chain? It's a long shot.....if you heard that sizzling up by the distributor that's a clue.... are all of your grounds good (left front of intake manifold, rear of left cylinder head, battery ground)??
Click to expand...

I was kind of thinking this as well, but if that were the case why would the truck fire on starting fluid but still have no injector pulse? Doesn't the injector pulse come from the ign mod, and with a bad ign module there wouldn't be spark to fire the starting fluid... Just wondering. inquiring minds want to know. Sounds to me like the truck jumped out of time either via the dizzy or cam timing as you suggested but why would it lose injector pulse?
 
Syclone#2960

Syclone#2960

What ever it takes!!
Re: NO FUEL FROM INJECTORS...no start

injector cycle on scan tool reads 9.2ms...does not change when cranking.
 
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