Topic: Adding a TB spacer, larger injectors, and MSD ignition. Is it worth it???

[TahoeYJ]

I was going to post this over on Jeepforum but they're all a bunch of freakin' 4 cylinder haters over there 

I've already added a 4.0 TB and done minor intake porting (Almost finished porting my old manifold from my old motor, whereas the current one I barely cleaned up the ports). My plans are to add an MSD 6A box and Blaster coil, along with some larger injectors (Say 19lb?) I keep thinking I can safely add some more fire and fuel to my 4 squirrels WITHOUT killing them... Is it possible? I don't beat the hell out of it so I figure if I compensate for added spark with more fuel or vice-versa I shouldn't do much if any harm. I added a Blaster ignition and coil to an old 4.3 S-10 Blazer I had and noticed a difference right off the bat. MUCH improved throttle response, better fuel economy, etc. I've also seen 62MM TB's, but I don't have the $$$ for that, and until I added forced induction (a ways off for now    ) I think the stock 4.0 TB will suffice.

I figure this is one of those common sense questions, since I've already tried a similar set-up I should know what to expect, but I never added more fuel nore much extra air, so I think these few mods should do the trick. With a good watch I can get everything off Ebay or the like for probably under the $300 mark and with everything added at once, it should be a worthwhile investment.

Anyway, any input is appreciated. And forget those 4 cyl haters on JF, I'll keep my 4 poppeer that gets great mileage and still cruised right along with the 4 liters 

[Jeffy]

I'd forget the MSD and go with the Performance Distributor setup.  It's not only cheaper, it works well.

Some 19# Ford Design II Injectors would also be nice since you're getting more air and more spark from the other mods.

Then I'd consider doing a electric fan conversion.

http://4bangerjp.com/forums/index.php?topic=29.0
http://4bangerjp.com/forums/index.php?topic=3479.0
http://4bangerjp.com/forums/index.php?topic=3781.0

If you do the fan you might want to consider this as well.

http://4bangerjp.com/forums/index.php?topic=400.0

[TahoeYJ]

From what I read it seems like the PD set-up is a pretty good way to go! But... If I don't mind spending the bucks on the 6A box (which I don't), I think that would show an even greater improvement if paired with the PD set-up. Witht eh MSD I almost wonder if I could run a set of 24 LB injectors, but I worry that might be too rich? I'm worried about leaning it out too much by adding a hotter ignition (I think that was the death of my 4.3...), but don't want to make it too rich either. The only way to find out though is to only try it and see what happens 

Do you have a link to the PD set-up, and a price for it as well? If it comes with a new coil I might as well pick it up since I planned on swapping mine when I upgrade the ignition.
E-fan is something I'd like to do too, so sometime down the road that will happen as well

Thanks for the info!

[Jeffy]

From what I read it seems like the PD set-up is a pretty good way to go! But... If I don't mind spending the bucks on the 6A box (which I don't), I think that would show an even greater improvement if paired with the PD set-up. Witht eh MSD I almost wonder if I could run a set of 24 LB injectors, but I worry that might be too rich? I'm worried about leaning it out too much by adding a hotter ignition (I think that was the death of my 4.3...), but don't want to make it too rich either. The only way to find out though is to only try it and see what happens 

Do you have a link to the PD set-up, and a price for it as well? If it comes with a new coil I might as well pick it up since I planned on swapping mine when I upgrade the ignition.
E-fan is something I'd like to do too, so sometime down the road that will happen as well

Thanks for the info!

I don't think you'll see much improvement with 24# injectors.  I know the 19# are still controlled by the PCM enough to pass CA Emisison II testing.  Actually my Jeep passes well below the max limits.  Since stock YJ injectors are 17-ish, 19 isn't a large jump with a stock setup.  The only time you might want to try 24# is with forced induction.  Even then you might be able to get away with the 19's and a dedicated FMU and a dyno tune.  There is a turbo thread that talks about this.

Really though, what you need is a wide-band O2 sensor if you want to know what the engine is doing.  With mild addons, the stock PCM is able to compensate.

The PD system is a complete setup.  Plug wires, distributir cap, rotor, and coil.  I ran a Jacobs Ignition Omni-Pak/MSD wires  before the PD and still found the PD to be a better system.  I don't see any reason to run a MSD and a PD together.  The advantage of the PD system is that it's simple and the system stays pretty much stock.  It's also inexpensive.  Last time I looked the complete PD setup was under $200.

[tallrugbyguy]

I  have the 62mm tb (great add on) and ill soon have a k&n cold air intake.
after the efan conversion
what is the next best add on? injectors or ignition system? any point in doing one with out the other?

[TahoeYJ]

From what I've read it seems like either one by itself will show some improvement, but not very much To get the benefit of either the hotter spark or more fuel, you'll need one or the other, depending on what you do first. Adding the 62MM TB was a great start though, more air + more fuel+ hotter spark= more power 

[jcsanders79]

I'd say its only worth it if you tie it all together with a Stage I or II chip.

[tallrugbyguy]

hmmm chips eh, just not sure if i wan to go that far. the body has more then surface rust and there seems to be at least a little on every  main body part.
kinda a question of wit till i get a jeep with a better body or try to fix this one....hmmmm

[Jeffy]

There are no chips for the YJ's...

[jcsanders79]

There are no chips for the YJ's...

Oh...

[Jesse-James]

There are no chips for the YJ's...

There is one, the Venom 400. Not sure how much it actually does though.



http://www.directauto.com/product-exec/product_id/41482/nm/1991_1995_Jeep_Wrangler_2_5L_Venom_400_Control_Module

[jfrabat]

There is one, the Venom 400. Not sure how much it actually does though.



http://www.directauto.com/product-exec/product_id/41482/nm/1991_1995_Jeep_Wrangler_2_5L_Venom_400_Control_Module

First time I see one of these...  I think it only adjust the MAP and TPS readings, though.