1st Generation Specific (1979-1985) 1979-1985 Discussion including performance modifications and technical support sections

post dlidfis trailing concerns

Thread Tools
 
Search this Thread
 
Old 07-10-07, 12:44 PM
  #1  
Senior Member

Thread Starter
iTrader: (1)
 
sevens4me's Avatar
 
Join Date: May 2006
Location: State College, PA
Posts: 459
Likes: 0
Received 0 Likes on 0 Posts
post dlidfis trailing concerns

I just did DLIDFIS on my '84 GSL-SE...The original writeup said to move the trailing wires on the D.cap to the leading positions. Do you also move the wire from the trailing coil from it's original position(T) to (L) also, or leave the coil wire alone and just change the plug wires on the cap? It starts and runs either way, but seems really "quiet" (exhaust)and slower revving with the Trailing coil wire in its original position. When I moved the coil wire also, it seems "louder" (exhaust) and really lacking in acceleration, also I still get backfires...Which is the correct way to do it? What about my vacuum advance now?
Old 07-10-07, 12:52 PM
  #2  
Say hello to Mr.Wankel

iTrader: (7)
 
dbragg's Avatar
 
Join Date: Nov 2004
Location: Cartersville, Ga
Posts: 5,962
Likes: 0
Received 1 Like on 1 Post
i did this swap on my DD 85 GSL. i used a 2nd gen coil for the leading. all i did was swap the + and - wires from the stock coil to the 2nd gen coil and swap the spark plug wires. after that all i did was swap the trailing wires on the dizzy cap. i put ALL T wires in the L position. that includes the one from the coil.

i still have my vacuum advance hooked up. id advise just doing a recheck of the timing. unhook the V advance and plug it at the dizzy and carb. then check the timing. id also go through and make sure all your connections are good and everything is wired up properly.

id did this and noticed a change in the exhaust not, but the car drives great. this is really a very simple mod to do. id advise using the 2nd gen coil though.
Old 07-10-07, 02:18 PM
  #3  
Full Member

 
DavidMyers53's Avatar
 
Join Date: May 2006
Location: Statesville, NC
Posts: 244
Likes: 0
Received 0 Likes on 0 Posts
When I did DLIDFIS ('83 12A), I didn't touch the trailing. Wanted it to be easy to go back to one ignitor on leading if I had a problem on the road.

- David
Old 07-10-07, 03:15 PM
  #4  
Rotoholic Moderookie

iTrader: (4)
 
vipernicus42's Avatar
 
Join Date: May 2002
Location: Ottawa, Soviet Canuckistan
Posts: 5,962
Received 32 Likes on 25 Posts
Since the main purpose of the trailing plugs is to help achieve a more complete combustion for emissions purposes, you won't notice a difference if you've wired your trailing properly or not.

The main reason they say to switch the leading to the trailing spot on the dizzy is because if you look under the cap, the leading parts are much beefier than the trailing parts of the rotor/cap. Just better for conductivity really.

So yeah, you can either leave trailing as-is, or you can switch your trailing stuff to the leading spot on the dizzy by moving all T spots to their equivalent L spots.

For the folks who've added the FC coil, what did you use for wires between the FC coil and the spark plugs? Did you have them custom made? FC wires? FB ones?

Jon
Old 07-10-07, 04:48 PM
  #5  
Senior Member

Thread Starter
iTrader: (1)
 
sevens4me's Avatar
 
Join Date: May 2006
Location: State College, PA
Posts: 459
Likes: 0
Received 0 Likes on 0 Posts
check timing?

This mod will change my timing? Or is it that the vacuum advance for leading no longer works because leading is not running through the cap? Before I did this, I asked around here and everybody pretty much said timing wouldn't be affected. Also, won't the timing flashes for the leading double(two coils now)? How would you read it? My car is harder to start when warm, and the exhaust tone has really changed, and it kinda spits and sputters(a tiny bit) when trying to drive at low rpm's (<4000). Is this normal? I expected a noticeable improvement in acceleration and had hoped the backfires would dissappear...I've noticed neither. What do you guys think?
Old 07-10-07, 04:58 PM
  #6  
Senior Member

Thread Starter
iTrader: (1)
 
sevens4me's Avatar
 
Join Date: May 2006
Location: State College, PA
Posts: 459
Likes: 0
Received 0 Likes on 0 Posts
T1, T2 switched?

Just thought about it, since I completely rewired everything to do with the ignition, is it possible my T1 and T2 spark plug wires are switched around? Would this explain my symptoms? The two plugs towards the front of the engine, are these 1's or 2's? Right now, the trailing plug towards the rear of the car is T1...Are the back plugs 1 or 2? I forget!
Old 07-10-07, 06:57 PM
  #7  
Full Member

 
DavidMyers53's Avatar
 
Join Date: May 2006
Location: Statesville, NC
Posts: 244
Likes: 0
Received 0 Likes on 0 Posts
This mod doesn't change timing. Timing changes when you rotate the distributor, or when the vacuum advance moves the stuff inside the distributor. Your leading wires no longer go through the distributor, but the magnetic pickup inside the distributor triggers the igniters. DLIDFIS is a lost spark system- both leading plugs fire at the same time, but the rotor isn't in the right position for one of them to do anything.

Since I changed mine to DLIDFIS, it starts better (hot or cold), runs better, and winds higher than before. Greatr all-round improvement.

- David
Old 07-10-07, 07:53 PM
  #8  
Round and Round

iTrader: (10)
 
74RX4's Avatar
 
Join Date: Aug 2002
Location: SW Florida
Posts: 1,516
Likes: 0
Received 3 Likes on 3 Posts
Originally Posted by sevens4me
Just thought about it, since I completely rewired everything to do with the ignition, is it possible my T1 and T2 spark plug wires are switched around? Would this explain my symptoms? The two plugs towards the front of the engine, are these 1's or 2's? Right now, the trailing plug towards the rear of the car is T1...Are the back plugs 1 or 2? I forget!
1 is front, 2 is the rear.
Old 07-10-07, 08:10 PM
  #9  
PSHH! PSHH! HEAR ME NOW?

iTrader: (3)
 
bad 83's Avatar
 
Join Date: Nov 2005
Location: Statesville NC
Posts: 4,132
Likes: 0
Received 4 Likes on 4 Posts
Originally Posted by DavidMyers53
This mod doesn't change timing. Timing changes when you rotate the distributor, or when the vacuum advance moves the stuff inside the distributor. Your leading wires no longer go through the distributor, but the magnetic pickup inside the distributor triggers the igniters. DLIDFIS is a lost spark system- both leading plugs fire at the same time, but the rotor isn't in the right position for one of them to do anything.
I've never understood what advantage this setup would yield without having some way to seperate the signal from the L1 and L2 coils. When you move the trailing wires on the dizzy, this changes nothing. I've been running the 2GCDFIS w/TT and locked dizzy on my turbo FB for about a year and a half with no problems, and I've been running the 2nd gen direct fire coil on my NA track car with no problems. I've always wondered how this could be a benificial upgrade on an ignition with a dizzy? Wierd.
Old 07-10-07, 09:09 PM
  #10  
Say hello to Mr.Wankel

iTrader: (7)
 
dbragg's Avatar
 
Join Date: Nov 2004
Location: Cartersville, Ga
Posts: 5,962
Likes: 0
Received 1 Like on 1 Post
no this wont change your timing. it was just an idea. more so incase you decide to "fiddle" with it while doing the mod. if you didnt, then dont worry about it.

id check to make sure everything is wired up properly, im 99% sure thats your problem. honestly, id just switch to a 2nd gen coil teh first chance i got makes thing simpilar and is supposedly better. i know i love mine.

the spark plugs from the drivers side go as follows:

top left- T1
lower left L1
top right- T2
lower right- L2

im using the stock FC wires without any issues.
Old 07-11-07, 03:55 PM
  #11  
Senior Member

Thread Starter
iTrader: (1)
 
sevens4me's Avatar
 
Join Date: May 2006
Location: State College, PA
Posts: 459
Likes: 0
Received 0 Likes on 0 Posts
Thank You!

Thanks alot for the info. and input, guys. I finally found a wire that broke at the crimp-on connector inside and was giving intermittent 12v to my one leading iginitors...Made a new wire, everything is great! Exhaust is quiet again, and no more smoking/ backfiring from the unspent fuel! Awesome low rpm city driveability, also!
Old 07-11-07, 04:01 PM
  #12  
Rotoholic Moderookie

iTrader: (4)
 
vipernicus42's Avatar
 
Join Date: May 2002
Location: Ottawa, Soviet Canuckistan
Posts: 5,962
Received 32 Likes on 25 Posts
Good to hear.

You should still re-time it anyway. Just to be sure. You never know what variables change when you go from one system to the other...

Jon

Last edited by vipernicus42; 07-11-07 at 04:05 PM. Reason: made stupid mistake confusing 2G-dfis with DLI-dfis
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
freq
Microtech
1
08-23-15 11:02 AM
freq
2nd Generation Specific (1986-1992)
0
08-21-15 03:30 PM



Quick Reply: post dlidfis trailing concerns



All times are GMT -5. The time now is 07:48 AM.