I've got a serious problem

[Kevin]

12.5-15 is where they should be. anything lower then that and they're already dying

[vilant]

Originally Posted by Kevin

12.5-15 is where they should be. anything lower then that and they're already dying

Ahh, I see, thanks. Well looks like I have dead ZR-1 til Jan.. This sucks.

[scottfab]

Originally Posted by vilant

I thought that if they were in the 12 range, they were still good. No? Or is that because the engine was cold.

All of mine are between 11 and 12.
Runs great.
I'm very interested.
Let us know if just replacing two (or all) injectors fixes you initial problem.

[vilant]

Originally Posted by scottfab

All of mine are between 11 and 12.
Runs great.
I'm very interested.
Let us know if just replacing two (or all) injectors fixes you initial problem.

Since I'm pulling the plenum, I'll do all 16. Don't feel like running into the same problem again, a few months down the road. I'll replace all plug and wires and maybe the coil packs too. I'll take pics and do a nice write up when the time comes. Hopefully sooner than later.

[Paul Workman]

Originally Posted by vilant

I thought that if they were in the 12 range, they were still good. No? Or is that because the engine was cold.

You can get fooled when they are cool. Checking them HOT is the only way to evaluate the winding's resistance accurately. (That goes for the coils too.) 12-12.5Ω is about average for OEM injectors, according to what I saw in my OEMs (when I had them) and what others have written here. Resistance may differ with aftermarket injectors, however. But, it is pretty clear that when the OEMs slide into the mid/low 10s, they're on the way out...fast!

I bought a set of Accels from Summit, on Marc Haibeck's suggestion, and it was amazing how much smoother the idle became. And, WOT performace was good enough for 432 RWHP on my stock block, stock cammed LT5. The injectors were $587 delivered, a couple years ago. The plain Jane LT5 GM plug wires (not roll stamped) were $70, and I don't recall how much the AC/Delco coils were, price wise, but must have been reasonable (or the cost might have left a better impression!) AC/Delco 41-602 plugs are under $2 a copy and good as new for almost 8k miles in mine, and good for some 11.0x second runs in Pete's car, and some 10 second runs in the FBI big inch LT5s too.

P.

[vilant]

Originally Posted by Paul Workman

You can get fooled when they are cool. Checking them HOT is the only way to evaluate the winding's resistance accurately. (That goes for the coils too.) 12-12.5Ω is about average for OEM injectors, according to what I saw in my OEMs (when I had them) and what others have written here. Resistance may differ with aftermarket injectors, however. But, it is pretty clear that when the OEMs slide into the mid/low 10s, they're on the way out...fast!

I bought a set of Accels from Summit, on Marc Haibeck's suggestion, and it was amazing how much smoother the idle became. And, WOT performace was good enough for 432 RWHP on my stock block, stock cammed LT5. The injectors were $587 delivered, a couple years ago. The plain Jane LT5 GM plug wires (not roll stamped) were $70, and I don't recall how much the AC/Delco coils were, price wise, but must have been reasonable (or the cost might have left a better impression!) AC/Delco 41-602 plugs are under $2 a copy and good as new for almost 8k miles in mine, and good for some 11.0x second runs in Pete's car, and some 10 second runs in the FBI big inch LT5s too.

P.

I'm curious as to why they should be hot. It's been a long time since I was in electrical school, but I learned heat increases resistance in electrical circuits. That's one of the reasons why super conductors have almost 0 resistance, they're cooled w/ liquid nitrogen. The readings I got when they were cold should be lower, then when they are hot. Thanks for the info, I'll be looking to price stuff out.

[mike100]

Originally Posted by vilant

I'm curious as to why they should be hot. It's been a long time since I was in electrical school, but I learned heat increases resistance in electrical circuits. That's one of the reasons why super conductors have almost 0 resistance, they're cooled w/ liquid nitrogen. The readings I got when they were cold should be lower, then when they are hot. Thanks for the info, I'll be looking to price stuff out.

for metal conductors, you are correct, but on coil windings, the magnetic wire is dipped in an insulation that is very thin. Once that is compromised, turns of the coil or entire sections may start shorting out making the total winding effectively shorter (less inductance and resistance). The heat just causes the coils to press into each other due to mechanical stresses in the injector assembly I suppose.

any noise could be the misfire, but if you have a bit of slop in the dual mass flywheel spring, you could be hearing that knock due to the rough idle. You are going to be amazed at how much better your car is going to idle (Like Paul said).

[vilant]

Originally Posted by mike100

for metal conductors, you are correct, but on coil windings, the magnetic wire is dipped in an insulation that is very thin. Once that is compromised, turns of the coil or entire sections may start shorting out making the total winding effectively shorter (less inductance and resistance). The heat just causes the coils to press into each other due to mechanical stresses in the injector assembly I suppose.

any noise could be the misfire, but if you have a bit of slop in the dual mass flywheel spring, you could be hearing that knock due to the rough idle. You are going to be amazed at how much better your car is going to idle (Like Paul said).

I see, thanks for clarifying. I know I can't wait, it's going to be a long 3 months.

[Kevin]

Originally Posted by vilant

I see, thanks for clarifying. I know I can't wait, it's going to be a long 3 months.

the way this weather is, you're not gona have much drive time left

[vilant]

Originally Posted by Kevin

the way this weather is, you're not gona have much drive time left

I've got no drive time left, lol. But when I do fix it, I'll take it out as long as the roads aren't snowy, wet, or salted.