INJ1 Fuse Blowing

[Dynomite]

I am looking for information on the INJ1 circuit (1995) to determine where I might have a short. I have no injector wires caught between the plenum and Injector Housing. This all started all of a sudden and the 10A INJ1 fuse keeps blowing. At least it is that circuit and not the Crankcase Sensor that is the issue I am thinking.

When the INJ1 Fuse blows you are DONE with NO spark on any of the 8. At least this happened in my driveway and not a thousand miles down the road

[WVZR-1]

Originally Posted by Dynomite

I am looking for information on the INJ1 circuit (1995) to determine where I might have a short. I have no injector wires caught between the plenum and Injector Housing. This all started all of a sudden and the 10A INJ1 fuse keeps blowing. At least it is that circuit and not the Crankcase Sensor that is the issue I am thinking.

When the INJ1 Fuse blows you are DONE with NO spark on any of the 8. At least this happened in my driveway and not a thousand miles down the road

I think the terminology of the fuse is maybe misleading. Maybe! I'd think you have no choice but to start at what GM seems to want to call the IGNITION COIL PACK (the component that all of the coils are mated to). Do you have the FSM for your '95 or are you attempting to work from a previous year?

[Dynomite]

Originally Posted by WVZR-1

I think the terminology of the fuse is maybe misleading. Maybe! I'd think you have no choice but to start at what GM seems to want to call the IGNITION COIL PACK (the component that all of the coils are mated to). Do you have the FSM for your '95 or are you attempting to work from a previous year?

I do not have the FSM. Was thinking/hoping it would be a simple short associated with the Injectors as this has happened to at least one other individual that pinched the Injector hot wire between the Plenum and Injector Housing

If I install a new 10amp fuse everything starts and runs perfectly.......for about 5 minutes then nothing. Actually....now if I insert a new 10amp fuse, the fuse blows immediately upon starting.

[WVZR-1]

Originally Posted by Dynomite

I do not have the FSM. Was thinking/hoping it would be a simple short associated with the Injectors as this has happened to at least one other individual that pinched the Injector hot wire between the Plenum and Injector Housing

If I install a new 10amp fuse everything starts and runs perfectly.......for about 5 minutes then nothing. Actually....now if I insert a new 10amp fuse, the fuse blows immediately upon starting.

The primary injectors are just a "splice" off of the circuit to the Ignition Coil Pack - try 8A-22-10 for '94/'95 years I think, 8A-22-8 for a '90. I can send you a .pdf for your '95 if you need.

[Dynomite]

Originally Posted by WVZR-1

The primary injectors are just a "splice" off of the circuit to the Ignition Coil Pack - try 8A-22-10 for '94/'95 years I think, 8A-22-8 for a '90. I can send you a .pdf for your '95 if you need.

A .pdf of 8A-22-10 to Dynomite07@prodigy.net would be superb

[XfireZ51]

Dyno,

Definitely an issue w the coil packs. That "injector fuse" feeds 10amps to the ignition coils. I know because that's what blew when I ran CnP on my motor a few years ago.

[Dynomite]

Originally Posted by GOLDCYLON

So the issue is the coil base or the coils in the pack or?

Any possibility of bent pin on the DIS connector ? But that cant be he just drove back and forth to Canada so this has to be a new failure like a coil. Ok I see it now Dom

Originally Posted by WVZR-1

Cliff - if you have and I'd think you do, I might just swap the coils and the module/coil pack as a package and see if the issue goes away. For you that's likely possible and maybe the easiest first step beyond the "head scratch" and "now what"!

Checked this morning and on a cold engine blew a INJ1 10 amp fuse immediately when trying to start the engine. Yesturday the fuse blowing was heat related as the fuse would not blow until the engine warmed up. This seems to me like it is an issue progressively getting worse and would indicate a coil pack and not a pinched wire.

Got Top End all apart and everything checks out fine. I even disconnected DIS from Plenum and plugged it in (with ground wire) and also plugged in Coils and could not blow the fuse. All injectors check out at 12 ohms but measuring back through ECM found one injector connector with 1/10 resistance of others but after fooling around found same on another ECM I plugged in...then the resistance disappeared on the injectors. Right now I have 4 new coils coming from Summit and will install them and connect things up including DIS without installing Plenum and turn on the switch. If INJ1 does not blow will install Plenum. I think I can plug in everything without installing the Plenum that might have impact on INJ1 fuse.

If I accidently hit start and the LT5 fires up without a Plenum I will definitely post up a photo. It might be a moon shot with direct air to the Injector Housings

Lee did not follow up on this
INJ1 Fuse keeps blowing TIPS

[WVZR-1]

Were you able to OR did you even try to locate the "splice" for the INJ wiring? Years ago that was the first place a tech might head towards if there was a known splice in the circuit.

[Dynomite]

QUOTE=WVZR-1;245966]Were you able to OR did you even try to locate the "splice" for the INJ wiring? Years ago that was the first place a tech might head towards if there was a known splice in the circuit.[/QUOTE]

I am assuming that is inside the car.....I figured I would see if I can eliminate the fuse blowing as above by installing everything but the Plenum and if not....will then start from the fuse panel and work through the fire wall.

This could be as simple as a temporary short in one of the connectors on each injector that if you move the connector around with key on would short out...I will try that also. I will wiggle, twist, push, pull on each and every connector and wire to see if I can blow INJ1 fuse.

The BIG Problem is accidently fixing this issue of INJ1 Fuse Blowing without knowing for how long. This started all of a sudden so must/most likely is a component rather than a pinched or worn wire but could be one of the injector electrical connectors as they can move a bit.

[WVZR-1]

See 8A-22-19 - Splice is S127 and I'd think it "in the vicinity" of where you're working. Search should work quite well with that .pdf, try S127 and G106.