91 ZR-1 Cutting Out Under Load

[Zr1 Destroyer]

[tomtom72]

Good deal Greg!

You wouldn't happen to have the part number for the GM coils?

TIA

Tom

[GregCrowe]

Originally Posted by tomtom72

Good deal Greg!

You wouldn't happen to have the part number for the GM coils?

TIA

Tom

D555: 10472401
D545: 10467067

Here's a great deal on the D555's:

http://cgi.ebay.com/ebaymotors/NEW-G...spagenameZWDVW

[tomtom72]

Thanks Gregg!

[bobbyhi]

Glad you got the Z running again.

I had a similar problem with mine. I switched to the Accel coils and the car wouldn't run very well when hot. I took it to DRM and Doug said that the Accels would fail because of the heat generated by the engine. He replaced with GM coils and the car ran just fine after that. Unfortunately that didn't solve my other problems but that's another story.

[scottfab]

Greg, sure glad you nailed it and really glad you hung onto the car.
I am curious about the Summit coils. Did they take them back?
What size wires are you using? 7mm or 8mm?
Since the summit coils were not subjected to high temperatures I am curious about the failure mechanism. If the primary to secondary winding ratio is large enough over stock then the secondary voltage could be exceeding the insulator breakdown voltage of the wire insulation.
(hotter spark)
The measured resistance seems to indicate this but there are other explanations behind the measured values. (quality and diameter of wire)
I sure would like to cut one of those summit coils apart.
Root cause analysis stuff.
Thanks
Scott

[GregCrowe]

Originally Posted by scottfab

Greg, sure glad you nailed it and really glad you hung onto the car.
I am curious about the Summit coils. Did they take them back?
What size wires are you using? 7mm or 8mm?
Since the summit coils were not subjected to high temperatures I am curious about the failure mechanism. If the primary to secondary winding ratio is large enough over stock then the secondary voltage could be exceeding the insulator breakdown voltage of the wire insulation.
(hotter spark)
The measured resistance seems to indicate this but there are other explanations behind the measured values. (quality and diameter of wire)
I sure would like to cut one of those summit coils apart.
Root cause analysis stuff.
Thanks
Scott

Yes, Summit took them back. I'm using new GM plug wires, think they're 8mm. I think the problem with the Summit/Accel coils was the 2 connection slots. They were too lose, didn't squeeze the terminals that plugged into them.

[scottfab]

Originally Posted by GregCrowe

Yes, Summit took them back. I'm using new GM plug wires, think they're 8mm. I think the problem with the Summit/Accel coils was the 2 connection slots. They were too lose, didn't squeeze the terminals that plugged into them.

Ok that makes sense. Good detective work. I put Accel coils in back in mid 2002 and have not had an issue. As I wrote earlier I did have a similar issue to yours with the stock ones but I believe two of them were defective (a few shorted windings) because they read lower resistance on the seconaries than the rest. One thing I did have to do was replace the stock wires with 8mm because they began arcing through the insulation with the Accels. I do remember having connection issues with the new coils on the input because they came with an orange rubber like gasket. The problem was some of the plugs on the wireing harness had the orange gasket still attached. That made for two gaskets and it would not make a proper connection.
Anyway, we're all glad I am sure that you're back on the road. Good timing too. Summer is knocking at the door.=D>

[ZR1North]

Originally Posted by GregCrowe

D555: 10472401
D545: 10467067

Here's a great deal on the D555's:

http://cgi.ebay.com/ebaymotors/NEW-G...spagenameZWDVW

What a great thread!

I pursued Greg's tip and purchased the "D555s" noted above, but I am not sure I want to install them now that I have them.

On these new units, the secondary windings are measuring 5.6 to 5.8K which is close to the GM recommended range of 5.6 to 5.7, but the primary windings are measuring 1.7 ohms - GM recommendation is .5 ohms. I am also a little suspecious of the part no on the replacements; it is 10482928 rather than the numbers Greg quoted above. I am thinking - don't think I will use these replacements. Am I being too cautious?

Originally Posted by ZR1North

What a great thread!

I pursued Greg's tip and purchased the "D555s" noted above, but I am not sure I want to install them now that I have them.

On these new units, the secondary windings are measuring 5.6 to 5.8K which is close to the GM recommended range of 5.6 to 5.7, but the primary windings are measuring 1.7 ohms - GM recommendation is .5 ohms. I am also a little suspecious of the part no on the replacements; it is 10482928 rather than the numbers Greg quoted above. I am thinking - don't think I will use these replacements. Am I being too cautious?

Another too good to be true? Those are half the cost of AC delco direct from delco.