[Viper Pilot]

Collector gaskets for Edelbrock headers (which were completely trashed on my car) are unavailable these days, so I asked a guy in our neighborhood who operates a badass machine shop out of his garage if he could cut me some out of some high temp sheet material that I ordered from Summit Racing. He's going to be able to get 4 out of the sheet I ordered. I'll use one, keep one for the other side, one as a spare, and then send the other one to Dan who asked for a template in order to make quality sets for people in the future who might need them.

The head is still at the machine shop waiting for the valve to show up. Was hoping to get the thing back before this weekend but it looks like I'm out of luck as usual.

 

[Final GTS]

I'll use one, keep one for the other side, one as a spare, and then send the other one to Dan who asked for a template in order to make quality sets for people in the future who might need them.

Yessir. Once I draw them up and our new machine is here later this year, I should have no problem cutting those out of Copper sheet or similar for a permanent option. Also may be able to do something like a stainless gasket with a copper insert... that would work well too assuming I could find materials readily available.

 

[Viper Pilot]

Cylinder head is back from the machine shop and they said everything checked out perfectly. Let's hope that's true.

Poor timing though. It's probably going to be a couple of weeks before I can get back to the car. Wedding's and graduation parties this weekend and then we're heading back to Georgia next week so I can take care of the family property. Wish they would have had it to me last week. I had a 4 day weekend.

 

[Viper Pilot]

Well, finally got it back together. Fired it up and the backfire was still there on number 10 in the exact same area it was before which was an off idle tip-in. I nearly put my fist through the wall. Thankfully, there's Dan Lesser. We talked for a bit and started down the road of a possible issue with the injector harness or the driver in the ECM. I had already confirmed that the injector itself was good. Dan advised me to swap the injector harness connectors between 9 and 10 and see if the problem followed the harness. Didn't think I could do that due to assuming that it would introduce even more problems. Anyway, the problem did not follow the harness. Backfire was still due to number 10. The issue is not fueling... Hmmmm.

At that point, we both concluded that it had to be an ignition issue. He told me to swap the two wires on the same coil tower and see if the problem moved to the other bank. In the process of clarifying what he was asking I sent him the note I made of the coil plug wire locations when I changed the wires and plugs last year. I'm really glad I did that because he immediately texted me back with "That's your problem". My note matches the service manual locations, but the service manual is FUCKING WRONG. The pairing is correct but the locations of those pairings are not. He advised me to get a good look at the markings on the back of the coil and match up the wires accordingly. I did that and was rewarded with sweet, sweet music.

The thing that befuddled both of us was that I had never touched those wires or coils since I bought that car and had put 20,000 miles on it with no issue that I could discern until the backfire suddenly started one day. No one other than me had ever touched the car for maintenance outside of changing tires. It was there before I started step 1 in this process, which was changing wires and plugs, and it was there afterwards when I put the new wires back on in the exact locations where the old ones were. It's kind of an honor to have someone with as much experience as Dan say "I have never encountered anything like this before". The only thing he could theorize was that somehow cylinder 10 was getting spark that was relatively close to what it needed to be through luck of the draw or arcing of one plug wire to the other, and then suddenly that stopped and the incorrect firing order reared it's ugly head. The incorrect, but close enough to prevent backfire, ignition timing gradually stressed the valve and it got wobbly. When the backfire showed up and I traced it to number 10 and did the leakdown, the bad valve was not the cause of the backfire, it was a result of the root cause which was the incorrect coil plug wire locations.

Anyway, glad this is behind me. It was all worth it to see the look on my son's face when I told him the Viper is fixed and we can go out cruising again in the summertime. I also learned a lot about that car. Win-win.

With all of that said, you can't find a more solid dude than Dan. If you need something that he sells or a service he provides, give him your business. He answered every one of my calls and messages with a joyful and helpful attitude and is a really cool guy to talk with. As an automotive engineer, some of my questions were a little embarrassing to ask but he never broke my balls too much about it and gave me an incredibly thorough answer every time. We're rapidly losing resources for these cars and desperately need people like him around. Cheers Dan and, as always, thanks to everyone on the Alley for the years of solid advice and tech support.

 

[RobV]

It has been documented here by Dean about the SM being wrong then corrected in later years.

He posted pictures of the coils he manually numbered. I use that as reference in other threads here and on other forums. Well at least I tell to search for it.

 

[Viper Pilot]

Yeah, I found an older thread with a description (no pictures) and called/texted Dan to confirm that I wasn't crazy. As I mentioned, I had no reason to believe that what I had written down from the car's previous configuration was wrong. I couldn't believe it when I saw the thread. "How the fuck is that possible?!?!". Needed a sanity check.

 

[Viper Pilot]

Also, need to correct my previous comments. What was on the car DID NOT match the service manual. The 4 post coil pack was miswired but the 6 poster was fine.

This is how the coils were wired from the moment I bought the car, and it's wrong, but somehow managed to run well until it didn't....

Front of car
|||||||||
Top
1 7 3 5 9
Bottom
6 4 2 8 10

I changed the configuration to match the service manual and the engine ran even worse. The thing was like a machine gun so I immediately shut it down. That's when I got really irritated and confused, did a search, and then picked up the Bat Phone.

 

[Final GTS]

Im just glad its fixed, and the root cause was something easy!

For clarification to anyone who read, I originally was asking him to swap the top/bottom plug wires on the coil. This technically changes nothing as they are the same coil, but excludes an internal arc from a cracked coil. Swapping these would move the backfire to the paired cylinder if so.

When he sent me the drawing, I immediately knew there was a problem. Cylinders 9/10 are NEVER paired on a coil, its always 5/10, same thing for 5/8... it should be 5/9.

The lower two wires, 8 & 10 were reversed.

Easy fix... Hard to notice, especially when running for years without apparent problems. It had to be a bogus wire arc that was hiding the problem, thats literally the only explanation.

 

[Viper Pilot]

Another thanks to Dan for adding some details I forgot and sticking with me while I was frustrated and dripping with sweat through my stuffy work clothes (why would I take the five minutes to change....?) due to the 95 degree humidity laden heat. All I did was buy a gasket set from the man. He had no obligation whatsoever to deal with my horseshit but did so out of kindness.

 

[Brickhead]

What does Dan drink & how much to you send him?

Crazy thread…

 

[Viper Pilot]

Yeah, crazy indeed, but nothing abnormal. Shit like this always happens to me. I'm sending him a non-peated Scotch that's my favorite. Keeping what that specifically is to myself for now.

 

[GTS Dean]

just for future reference:

 

[Final GTS]

Yeah, crazy indeed, but nothing abnormal. Shit like this always happens to me. I'm sending him a non-peated Scotch that's my favorite. Keeping what that specifically is to myself for now.

If it makes you feel better, I carry the same torch, lol. I cut my diagnostic teeth getting rammed in the ass by the unlikely, unheard of, and generally regarded as impossible chains of events.

Oh, we made 5000 of those, but only one is screwed up? SEND IT TO DAN!

 

[97gtsRt10]

Yeah, I found an older thread with a description (no pictures) and called/texted Dan to confirm that I wasn't crazy. As I mentioned, I had no reason to believe that what I had written down from the car's previous configuration was wrong. I couldn't believe it when I saw the thread. "How the fuck is that possible?!?!". Needed a sanity check.

I am curious at what year was the layout in the manual corrected?

 

[97gtsRt10]

just for future reference:
View attachment 165932 View attachment 165933

So the coils numbers are correct, but the Gen 2 manuals are wrong?

 

[ViperTony]

So the coils numbers are correct, but the Gen 2 manuals are wrong?

It's the orientation of the picture in the manual that's off. For example, cylinders 5/10 and 9/8 are shown incorrectly in the manual when viewing the actual coil pack cylinder number orientation.

 

[Viper Pilot]

Correct. The diagram in the service manual is reversed in terms of the wire orientation for each coil pack. Look at Dean's picture above. The left side of the image is the driver's side of the car. You can see the problem. For example, the #1 wire is the top post on the outboard side of the car. In the manual, it shows it as the most inboard post.

From what I understand, the Gen2 manual was never corrected.

 

[Viper Pilot]

If it makes you feel better, I carry the same torch, lol. I cut my diagnostic teeth getting rammed in the ass by the unlikely, unheard of, and generally regarded as impossible chains of events.

Oh, we made 5000 of those, but only one is screwed up? SEND IT TO DAN!

I used to think it was nice to be wanted. Now, not so much.

 

[Final GTS]

Also another thing to add onto this... if anyone here wants, we do have the ability to laser engrave the firing order literally anywhere you may want, onto any material, or add it onto replacement coils that come blank/wrong to prevent this from happening.

 

[EllowViper]

I've seen some pretty messed up tattoos on people these days...just saying.