350 two fried coils in two days...Any Ideas?

[Kurtis]

I have tbi 350 conversion running pretty good and was getting pretty excited because its been a month of driving everday without issue. Yesterday I fried an ingnition coil... towed it home changed it ran fine but on my way home this morning fried another one. this time got the part fixed it and drove it home. Coils are only 20 bucks but i'd like to avoid buying one every 30 miles.

I found one wire on a relay that was closer to the frame than it should have been. Other than that off the coil itself is a white wire. Its for the tach i believe so when I did the install just capped it and left it. I noticed the cap was missing and this wire was touching the throttle body when I changed it the second time. Could this make a coil fry itself? I'm assuming that a positive signal is coming off that coil tach wire and the engine itself is of course grounded so it would short out I was just wondering if anyone agrees or knows of something else that makes coils die like this.

 

[Kurtis]

Its lame I had just talked to Dan at ruff stuff about getting the SOA kit together as I was getting fairly confident in the truck but now this is defiantly a minor setback.

 

[inkpot]

Howdy! Had a similar problem on that engine setup once. Had an aftermarket air cleaner on it, and when it was positioned JUST RIGHT, it was OK, but when it was rocked, or bumped a bit, then the bottom of the air cleaner would make contact with the terminals on the top of the coil. HTH John

 

[Kurtis]

Hmm. . I noticed with mine that the air cleaner wasn't seated right when i took it off maybe it was to close it was getting inside that spacer one of the tabs was a little bent and it was tipping a little. Hopefully it was that or the tach wire.

Thanks John I gotta get it sprung over once I can get this little quirk solved. I also got my notice for emissions in my email yesterday. Any suggestions before I take it in? Egr is hooked up cat is in the exhaust line. I didn't delete anything out of the harness. Exhaust doesn't smell unusally bad. I ordered a gas cap but other than that is there anything special I need to do when I show up for testing, or can I just show up tell them I just completed a swap and have them run it?

 

[inkpot]

Howdy! I just drive it in and let them figure it out. I don't say anything. They usually ask me two or three times: "Is the a V8?" The computer doesn't show it available until 1998. I just then them why, yes it is. For the dyno test, it has to sniff out equal to or better than the original specs for the rig, regardless of the engine. For the visual, they need to see that everything that was on the rig originally is still there and hooked up. With the Chevy engine, most of it is on the motor, instead of the firewall/fender. They usually bring out a supervisor to verify the visual exam. In 17 years of testing, I have only failed on the sniffer about 3-4 times. Then a regular tune up and oil change has been enough to pass. Good Luck. John