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 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.

Yes.....from what Dave sent me it appears the INJ1 10 amp fuse feeds the coil packs.......but now what exactly am I looking for (what to measure to verify the issues)?

This issue started with the INJ1 fuse only blowing after the engine was warmed up for about 5-10 minutes. If I then (after engine is warmed up) replace the INJ1 fuse it blew immediately upon starting. Now the INJ1 blows with engine cold or warm and immediately upon trying to start the engine.

Also.....the INJ1 10 amp fuse does feed the Primary Injectors it appears and would also blow INJ1 if you pinched an Injector Wire or otherwise grounded an injector wire as others have done.

It appears the Plenum comes off (a 10 minute job) and then the coil packs...but again....what and where to measure?

Are you saying the coils themselves may be shorted out?

Anyway.....it also appears any pinched wire between the fuse block and coil packs/injectors could be involved (DIS and ECM may not be involved since neither would warm up within only 5-10 minutes)?

I think I can measure ohms backwards to INJ1 fuse (the hot wire) to verify if any path from the coil packs or Injectors is grounded which would indicate a short. But in this case I would not find any issues unless the components I am testing were warmed up.

I do not wish this issue on anyone who has driven the ZR1 some distance from home base.....
For me....I just got done with a 2,000 mile round trip to the Canadian Border to get a Customs report for the 95' ZR1 with NO issues as this issue happened a couple days after that trip backing the ZR1 approximately 100 feet from my garage, lift, and tools

I tested out (on the 2,000 mile road trip) ZFdoc rebuilt black label Transmission that I installed in my 95' along with new throw out bearing, new pilot bearing, and new U-Joints installed in the main drive shaft. Have to say......everyone should get a ZFdoc rebuild....those transmissions ARE THAT GOOD especially with the short throw Shifter.

Thanks guys...appreciate the information

[WVZR-1]

Do you maybe just start at the DIAGNOSTIC CONNECTOR PIN G? 8A-22-11 I've no idea Cliff BUT ...

Have you been in the car around and behind the IP on the Right side? Maybe check C237

How about at the PASS THRU P101 to the right of blower housing/evap? Should be an image 8A-201-3 (page 1262 BOOK 2)

[XfireZ51]

Cliff,

The issue causing my fuse to blow was due to the fact that the LSx coils require 20amps for charging. I was ignorant of that fact when I put things together. The motor ran for 30-45sec. (Idle was really smooth I might add, even at first start),
but then it started to stumble and it finally died. I traced the shutdown to the Inj.1 fuse. Once I put things back to stock, motor ran fine.
So my suspicion for u is that as the coils warm up, the current draw is blowing the fuse. That's why I posted what I did.

[GOLDCYLON]

Originally Posted by XfireZ51

Cliff,

The issue causing my fuse to blow was due to the fact that the LSx coils require 20amps for charging. I was ignorant of that fact when I put things together. The motor ran for 30-45sec. (Idle was really smooth I might add, even at first start),
but then it started to stumble and it finally died. I traced the shutdown to the Inj.1 fuse. Once I put things back to stock, motor ran fine.
So my suspicion for u is that as the coils warm up, the current draw is blowing the fuse. That's why I posted what I did.

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