home register FAQ memberlist calendar

Go Back   Turbobricks Forums > Mechanical > performance & modifications

Reply
 
Thread Tools Display Modes
Old 11-29-2018, 05:36 PM   #1
maxitoman007
Board Member
 
Join Date: Feb 2017
Location: Calgary, Alberta, Canada
Default MSD-5. Still an upgrade? Beating Rich Misfire.

Found an MSD-5 ignition box for really cheap right here in the city. was wondering if it would have the same effect as say an MSD-6a. Anybody have any experience using these boxes? My 87 740 Turbo with mods is suffering from weak spark and pretty rich AFRs so I'm currently looking for a cheap solution to light my wonky ratios.

Here's the box:
https://www.kijiji.ca/v-view-details...dId=1355054369
maxitoman007 is offline   Reply With Quote
Old 11-29-2018, 07:27 PM   #2
dbarton
Bored Member
 
dbarton's Avatar
 
Join Date: Nov 2002
Location: North of Dallas
Default

I've put a few MSD 6a boxes in my 240s over the last 20 years, but I don't know about the 5. That one looks like an antique.

My reason was to cure spark blowout under boost (over 12 psi) and it solved it each time. Before the MSD I could only reduce blowout by closing the spark plug gap to about half of normal. With MSD I could actually run a much larger gap than normal, but I don't these days.

I don't know if it will help with an over-RICH misfire though.
Dave B
__________________


'84 242ti, owned since 2003. Always garaged since brand new. Old-school rounds because. B21FT, iPd Springs/Sways, SDS EFI/IGN, TD04HL-15G, T5Z trans with 0.73 OD retrofitted, 3.91 diff with G80.
Volvo seeks Divorce from Volvo Enthusiast Community: www.prancingmoose.com/#novolvo
Dave's Volvo Page: www.davebarton.com
dbarton is offline   Reply With Quote
Old 11-30-2018, 01:03 AM   #3
maxitoman007
Board Member
 
Join Date: Feb 2017
Location: Calgary, Alberta, Canada
Default

Fair enough. There is an MSD SCI which is has the same guts as an MSD-6a but just a different case colour for quite cheap around here at $90 CAD so I'm thinking that might be the best route.
maxitoman007 is offline   Reply With Quote
Old 11-30-2018, 09:28 PM   #4
lummert
Board Member
 
lummert's Avatar
 
Join Date: Jan 2008
Location: Portland IN
Default

Have you tried lowering the fuel pressure?
__________________
Trying to understand stupid people is like trying to pick up a turd by the clean end.
lummert is offline   Reply With Quote
Old 12-01-2018, 02:30 AM   #5
maxitoman007
Board Member
 
Join Date: Feb 2017
Location: Calgary, Alberta, Canada
Default

Quote:
Originally Posted by lummert View Post
Have you tried lowering the fuel pressure?
I have not, however my base Idle is around 14.4 which isn't too bad so I figure my issues arise from using LH 2.2 fuel maps without the usual conditions (20psi+). Only tuning I've done is through leaning out the mixture using the MAF as much as possible. It seemed to work for a while and I would get a good burn all the way to red line however it has gotten progressively worse. It started with just a large flat spot in the powerband when the mixture got rich to the point where it couldnt be ignited, however power would come back once boost leaned out the mixture and it was once again able to burn. Now however, it is as if this flat spot is endless...

If you want more info on the issue, I have a thread about it here (I'm pretty sure you made a few posts in there...):
https://forums.turbobricks.com/showthread.php?t=343102
maxitoman007 is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump


All times are GMT -4. The time now is 08:01 AM.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2018, vBulletin Solutions Inc.