TCCoA Forums banner

1 - 20 of 30 Posts

·
Registered
Joined
·
14 Posts
Discussion Starter #1
Hey all, I'm new to the site and learning how to navigate it but I joined up because it seems like a lot of guys over here have some great knowledge about the SVO style supercharger.

I've got one installed on my 1996 Mustang Gt but haven't been able to get it running correctly for months. I have a nice misfire at idle that won't go away. I've been doing remote tuning through dirtydirtyracing.com since he reached out to me with experience tuning these things.

I wanted to chase down the misfire before I purchase better injectors and throw more money into it.

I changed back to my stock injectors, stock coil packs (was converted to coil on plugs), stock MAF sensor, took apart my wiring harness to look for broken wires, and returned the tune to stock... still have the miss.

I think it comes down to my vacuum harness, I haven't been able to find direct information on how to run the vacuum lines and I think they are off (possibly causing the misfire).

I did some digging on this forum and MikeB said he had a sketch he emailed someone. I am unable to send PMs so I figured I'd make a post. Does anyone have a complete vacuum diagram for these?

Thanks!
-Iz
 

Attachments

·
Registered
Joined
·
4,147 Posts
That SVO normally comes with 30# injectors. I have a FRPP PCM - Tuned for the SVO for 96-98 Mustang sitting on a shelf somewhere around here also.
 

·
Super Moderator
Joined
·
11,871 Posts
Pull the plugs and see if you can find the cylinder that's missing. What plugs are you running what's the gap?

What size fuel pump are your running? Have you changed the fuel pressure regulator?

You definitely want a bigger MAF and injectors than stock. 30lb minimum injectors 42lb recommended.

I'm running a 90mm Lightning MAF sensor.

Try calling RobertP to discuss options. You can reach him at 910-947-7044.
 

·
Registered
Joined
·
14 Posts
Discussion Starter #7
Thanks for the diagram Mike! I appreciate the help!

dDUBb: I have a set of the 30# injectors originally from the kit but they looked pretty beat up. I bought some 42# injectors off eBay but I don't trust their quality after the first two remote tunes were loaded on my car. I'm leaning towards buying a set of 47# with EV1 adapters from the tuner I've been using. If that doesn't work and you want to let the FRPP PCM go, let me know what you want for it.

Trunk Monkey: I'll plan to pull the plugs after I re-arrange some vacuum lines. I just installed NGK TR6 plugs gapped at .033.

I'm running a Walbro 255 lph pump 42# injectors (which may need replaced with higher quality brand) and a 90mm MAF sensor

I put the stock injectors and MAF back in and reloaded the stock tune so I could try to pinpoint the misfire without other variables being in the way. I will keep you guys posted but I hope fixing the vacuum lines makes a difference.

Thanks for the information and phone number for Robert!
 

·
Registered
Joined
·
14 Posts
Discussion Starter #8
I ran the vacuum lines as MikeB described and started messing around with the car while it was running...

I pulled all the spark plug wires from the cylinder heads one at a time and each one is firing away when the engine is running. The engine seems to stumble when I pull each individual injector too so I think those are doing fine too.

I watched an old video of right after I installed my comp xE-262-ah cams 2 years ago and realized that my engine shook a little more than normal (but ran great for 2 years). So I pulled the belt off and realized that the knocking sound is coming from the snout of the supercharger when I rotate it by hand back & forth. I'm not ruling out a misfire but the snout spring might be what's causing my knocking issue.

I'll keep you guys posted as I dig deeper into it but I really appreciate the help so far

-Iz
 

·
Registered
Joined
·
14 Posts
Discussion Starter #9
I let it run and it's idling smooth except for the sound of a box of rocks shaking in the front of the supercharger. I used a dowel rod to pinpoint the sound and it was coming from the snout. After seeing all the slack it has when turning the pulley by hand (no tension with the belt removed) and doing some googling it looks like I have a bad coupler.

Anyone have advice on a good coupler to replace it with? And does anyone know if a standard m112 coupler fits on this unit?
 

Attachments

·
Registered
Joined
·
4,147 Posts
Upgrade to a solid coupler. Plenty available for low prices.

Normally when I see a bad coupler they come out in pieces.
 

·
Registered
Joined
·
14 Posts
Discussion Starter #11
I ordered a solid one like you recommend, and yes the price is reasonable enough that I should've replaced it regardless before the install. The stock plastic one on mine was almost fused to the snout pins and the spring moved freely back & forth so it was probably a matter of time before the slack broke it more
 

·
Registered
Joined
·
14 Posts
Discussion Starter #12
Installed the new solid coupler last night, the thing fit so snug in the pins that it took some tapping with a plastic hammer to get the snout seated and there is no slack in the pulley anymore.

I wanted to give the rtv gasket some time to dry before filling it with oil so I'll fill it up tonight after work and see how it runs.
 

·
Super Moderator
Joined
·
11,871 Posts
Good Deal. Glad to see you're getting it sorted out. You're in for a real treat once you get that running right.
 

·
Registered
Joined
·
14 Posts
Discussion Starter #14
Threw some oil in the supercharger case and fired the old pig up. It's running pretty damn smooth now with the new pulley and stock MAF, Injectors, and tune. It is rich as hell (14-15 to 1 on my AFR gauge) but that'll be sorted out.

I'll probably email my tuner tomorrow and order some FRPP injectors so he can finish remote tuning the car with the proper supporting air and fuel components. I also need to put the wiring harness back together and clean things up a bit.
 

Attachments

·
Super Moderator
Joined
·
10,302 Posts
14 to 15 on a blown engine is not rich, IMHO.
 

·
Registered
Joined
·
4,147 Posts
14 to 15 on a blown engine is not rich, IMHO.
14.7 is Stoichiometric on a NA gasoline engine with a factory tune .. at 11% rich, you would want to get it to 13.1. On a supercharged engine, you'll be looking for about 11.47 AFR - the tuner will figure it out. :wink2:
 

·
Super Moderator
Joined
·
10,302 Posts
Exactly; my personaly written tune went to 12.4:1 to stop detonation during cold mornings.
 

·
Super Moderator
Joined
·
11,871 Posts

·
Registered
Joined
·
14 Posts
Discussion Starter #19
I guess I don't have much data to support my claim that it's running rich but it stinks like fuel pretty bad but that might be ok!

I ordered the 47lb injectors last night and will wait for them to come in
 

·
Registered
Joined
·
14 Posts
Discussion Starter #20
Thanks for the link TrunkMonke. The tuner has been great to work with so far and has put up with my extremely slow progress so I figure I should give him my business for (hopefully) the last significant purchase for this project. I think the extra few bucks for a good shop might help out a little.

I'll keep that site for future use, they've got the best prices I've seen so far.
 
1 - 20 of 30 Posts
Top