Contour Enthusiasts Group Archives Forums Modifications 3.0L Duratec Put on my SVT UIM, with stock throttle body.

I installed my SVT UIM last night. I am still waiting on my Mustang TB to come. As I expected based on what I read, there was a big power drop down low and huge loss in throttle response. The stock TB is a big bottle neck on a SVT manifold, I can actually tell when the secondaries open now. Up in the higher RPMS above 5K it did seem to help, I noticed that the car seemed to have a bit better acceleration between 5-7K.

I am still running 24 lb injectors on a stock ECU, I am waiting on my headers to come before I go for a tune. I tried a little trick that did seem to work, I installed a one way check valve on the vacuum line going to the fuel pressure regulator, so as to keep the fuel pressure at 45 PSI at all times, even WOT. I know it sounds like a ghetto fix but it seems to have helped, but I can't say 100% because I can't prove it with a wide band o2 etc. This will only help the air fuel mixture at WOT.

I have a question maybe someone can answer, when I install the Mustang TB will I still not have the same type of throttle response I had with the stock manifold/TB? Will the air velocity just be too low? I am sure it will help once the secondaries open, and once the headers go on.

Maybe the stock UIM and TB were probably not as much of a bottle neck as I thought, I am guessing the air velocity was doing the trick. Or maybe I'll be blown away once I install the Mustang TB, I am hoping this is the case

Anyone else running a 3.0L port matched with stock UIM and TB?

I had the Mustang TB on my Contour. You loose your cruise control using it and will have to hack and slash the TB bracket and cable to make it work. Dan G could weigh in having driven with both. IIRC he said he could not feel any diffrent between the Mustang and SVT. On the Mustand TB, he noted a problems with the plate positioning and idle. I'm sure GTO Pete has a diffrent opnion and could give you some feedback in contrast to mine. Hope this helps...

You are really gonna have to fix the fuel problem first. The mixture is all jacked up and if you are running too rich that will kill throttle response as well. You have no way to tell right now what mod is doing good/bad.
Your ghetto fix is probably what is allowing the engine to pick up some power in the upper revs. NONE of it is probably being significantly affected by the SVT upper I would guess.

If you were to use some SVT 19# injectors then your problem might be greatly helped because the stock pcm may be able to pull enough fuel on them.
Honestly, I'd run your stock 17lb injectors if you can (if they are top feed) and then just slowly test it to see if you are pinging. Of course when you do that you remove the ghetto fix...though I can't see how that mod does anything for you anyway. If you just unhook and plug off the line the regulator will maintain 45psi. Sounds almost like you have it fixed for 55psi all the time and that would make it worse all the way around.

The damned best way is to chip the thing for use with 24's and leave everything else in the code alone, and stock! Then when you can afford to tune it you can screw with the other settings.

From what I have gathered, leaving the vacuum line off the fuel pressure regulator will leave the valve in the FPR in the down position thus creating more pressure? By trapping the vacuum in the FPR you are pulling up on the valve and reducing the pressure. Either way I can pull it off in 30 secs.

I hear you on the 24 lb injectors running on the stock ECU, I have been running this way for almost a year now. I tried to purchase an Xcal from steeda.ca, they are local to me. They wouldn't sell it to me without a dyno tune, I asked for just a base program to take into account the 24 lb injectors and they said my cars setup is too unique and they cannot create a tune for my car without having it on the dyno. So I want to have all my mods installed first.

The throttle response was very good with the stock intake and TB with the 24s. I had a scanner hooked up to the car once and it was pulling 17% fuel on the long term fuel trim and about 12-13% on the short term fuel trim. For cruising etc it wasn't too bad.

Another question, the SVT ECU with 19lb injectors on a 3.0L would run lean up high, but would a stock ECU with 19 lb injectors still run lean up high or would the longer pulse width compensate and actually run rich still? I am not about to go swap in 19s but I am just curious, it will give me a rough idea of how rich I am actually running. I tried swapping in 19s once off a 2004 towncar but something didn't feel right, I think the spray pattern was incorrect.

The 24 lb injectors I have are blue off a 99 split port Duratec.

Once all the mods are on I am going for a proper dyno tune and I will stop all the "ghetto" fixes LOL It was a great learning experience, I have a much better understanding of how fuel injection works now.

SVT ECU and 19# injectors won't run lean at all on a 3L.

A 3L with any of the N/A setups we can make can't exhaust the potential for the 19# injectors. Maye some very agressive cams at high rpm might do it but not stock or SVT cams.

AS for the xcal2,

Just order it through Brenspeed for your PCM code, stock MAF and 24# injectors with no other changes made. He'll be happy to hook you up for around $300-$350 shipped I think and it will probably run right off the bat. Again, as long as you don't change the MAF from stock. AS soon as you do that you will have to play a game to get the transfer function right.

With 24# injectors and no tuning, my 3L was running WAY rich. The 19# injectors were actually pretty good as far as A/F is concerned. Could have used a little leaning out, but it was good. Let me know if you need some 19# injectors, cause I have some that I'd let go for pretty cheap.

Mark

Installed the Mustang TB.

Image no longer available.

Used parts off a ATX to get it going. Made a home made intake pipe, it is stainless steel from a truck exhaust.

It did make a difference in power and the part throttle pull is back, even more so. For daily driving it made the car way more fun to drive, WOT it feels like it gained a few HP.

Only real cost involved was the TB which cost $2.25 US plus $20 shipping (gotta love ebay) and $24 CAD for the couplers and clamps, most everything else came from my 99 ATX parts car. Aswell as the cost of the Mustang TB gasket $5 CAD.

I am using the Original ATX return spring doubled up, the pedel is really stiff and precise. Don't have the nasty slop of the whacky original linkage mechanism.

Just incase anyone is interested, parts used:

-99 ATX cable attachment welded on to the mustang rod. This involves tacking on the cruise control cable attachment on top after.

-99 ATX throttle cable

-99 ATX cruise control cable

-99 ATX cruise control module (The cable was much thicker on the 99 vs my 96)

-99 ATX cable bracket (had to enlarge the holes to shift it closer to the TB and hack off the lower bolt attachment

-99 Mustang GT TB

-Silicon couplers

-Stainless Steel Exhaust pipe (a tad past 3" inner diameter)

-Three small tubes to weld on to the pipe.

-Also made a throttle stop bracket which is attached to the top right TB bolt.

-Misc hoses off the parts car.

-Oh yeah Mustang TB gasket and SVT TB gasket.

Y2KSVT I am sending you a PM.