How are you makng your 94/95 331 stroker run right

[stangbangerrick]

Here's the low down have a 1995 gt with a 331 stroker. Got it dyno tuned and it ran great for about 2 months. My tuner said there's nothing wrong with the tune. My friend and I tested it with a LM1 with the chip out and with it in and it was running lean at WOT. Just changed about everything and checked everything. Put in a new electric fuel pressure guage so I could keep an eye on the pressure when I drive, changed the TFI and Computer checked timing. Well the fuel pressure guage is set at 40psi with the vacuum line off and hose pluged. The car was running ruff and with did a vacuum check and it was ok. With the car running at idle we shot a little starting fluid into the vacuum hose that is connected to the air intake tube located by the oil fill tube and the idle smooth out and it ran real nice. I turned off the car and we hooked up the LM1 and started the car and let it come up to temperature at idle and the A/F ratio was 19, shot in a little starting fluid and idle smooth and A/F 14.7. and then back to 19. Pulled the vacuum line off the fuel pressure regulator and had to adjust the fuel pressure to 50 psi before I could get a 14.7 A/F ratio at idle. That being said I would have to set the pressure close to 60 psi in order to have a good A/F ratio at wot. Have not put the SCT chip on the new computer. Have 255lph pump and changed the fuel filter when I put the pump in last spring. I'm thinking that the fuel pressure guage is bad, or fuel regulator, maybe the MAF. What I need to know what are you guys/gals doing to make your 331/347 run when using the stock computer yea I running a Ford X303 cam. This car has always run lean. I need to fatten up the fuel ratio without all that pressure. If you look at my profile you will see a list of my mods. This car needs help!!

 

[64post]

Don't mean to get off your problem here, but, when it ran well what kind of rwhp did it make with that X303 cam? I have one and I have a 331 with a small comp cam I'd like to swap in the X303.

 

[stangbangerrick]

Don't mean to get off your problem here, but, when it ran well what kind of rwhp did it make with that X303 cam? I have one and I have a 331 with a small comp cam I'd like to swap in the X303.

After the dyno tune 320rwhp and 374lbs of torque

 

[final5-0]

I think too much focus is spent on fuel pressure in this case and in general
with the entire Mustang community

After all ... the pcm has no way to measure it in the first place

If the pcm has been ... tuned then it was tuned with the amount of pressure
being used at that time. Now ... if the pressure gets changed ... that change is gonna change the tune.

Basically ... when you tune the tune is broken down to two major parts

Closed Loop or driving around town with very little throttle
Open Loop or W O T

You tune very differently for both conditions :Word:

CL the O2's output determine how the pcm controls things
OL you pretty muchly use tables that control things

I'd say you need to find a different Pro Tuner
or better yet
Tune your Stang yourself

I don't see how you are gonna make any headway trying to tune with
fuel pressure or dizzy twisting

Grady

 

[64post]

After the dyno tune 320rwhp and 374lbs of torque

That's it?....320? Good torque #'s wow, Good luck with your lean issue(s)

 

[Adam95GT]

Im just learning to tune but from my understanding your not trying to tune for a perfect AFR at idle. You need to tune more by feel at idle. Some cars would rather idle at mid 16's and 17's. Closed loop is a whole different animal then open loop.


Also if you have large primaries sometimes the readings at idle from the wideband may not be accurate.


Also what are you considering lean at wot??? you should be seeing 12.5-13.0's

 

[stangbangerrick]

I think too much focus is spent on fuel pressure in this case and in general
with the entire Mustang community

After all ... the pcm has no way to measure it in the first place

If the pcm has been ... tuned then it was tuned with the amount of pressure
being used at that time. Now ... if the pressure gets changed ... that change is gonna change the tune.

Basically ... when you tune the tune is broken down to two major parts

Closed Loop or driving around town with very little throttle
Open Loop or W O T

You tune very differently for both conditions :Word:

CL the O2's output determine how the pcm controls things
OL you pretty muchly use tables that control things

I'd say you need to find a different Pro Tuner
or better yet
Tune your Stang yourself

I don't see how you are gonna make any headway trying to tune with
fuel pressure or dizzy twisting

Grady

You are right about the pcm not being able to read the fuel pressure, it's the MAF meter that sends a signal to the pcm based on airflow and set the A/F ratio along with info from the 02 sensors. I have not check the MAF fuctions with the new computer will do that today. Could be that the A/F tables loaded in the computer are wrong. Will check a number of thing to be sure.

 

[final5-0]

I got more time this morn to talk ............ SO

You say your Pro Tune was good for a couple months

I've seen what appears to be a tune slipping away
but in reality
Various things such as faulty parts, v leaks and the like are at fault

If the above has happened
then
The tune is not really at fault

In your case so many things have been changed .......
it might difficult to get back to where they were when things were good

I can understand changing things to find the problem
but
You really don't have enough data to analyze things as I see it

Again ... a change in fuel pressure will be counter productive to the tune

I guess I'm trying to say you don't have any way to KNOW FOR SURE
you were not lean after your Pro Tune ... you have to take his word for it

Also ... How can you BE SURE your readings are correct at this time

A up or down in pressure is a GLOBAL thing and what might be good for
WOT could hose up your driving around town part of the tune

Of course ... just the opposite could be the case as well

That my friend ... is what CUSTOM TUNING is all about

You have complete control to change things as needed
at ANY rpm or load condition

After some thought ... I think the best thing to do here is return things
back as they were when tuned and see how it runs

Grady

 

[stangbangerrick]

Im just learning to tune but from my understanding your not trying to tune for a perfect AFR at idle. You need to tune more by feel at idle. Some cars would rather idle at mid 16's and 17's. Closed loop is a whole different animal then open loop.


Also if you have large primaries sometimes the readings at idle from the wideband may not be accurate.


Also what are you considering lean at wot??? you should be seeing 12.5-13.0's

Dont know why it's running lean at wot all I know I have a issue with the fuel delivery, will troubleshoot today.

 

[stangbangerrick]

That's it?....320? Good torque #'s wow, Good luck with your lean issue(s)

Tuner said I could pick up 20hp with the holly intake, and he only took it up to 5900rpm, the X303 cam makes power up to 6200rpm

 

[final5-0]

Im just learning to tune but from my understanding your not trying to tune for a perfect AFR at idle. You need to tune more by feel at idle. Some cars would rather idle at mid 16's and 17's. Closed loop is a whole different animal then open loop.


Also if you have large primaries sometimes the readings at idle from the wideband may not be accurate.


Also what are you considering lean at wot??? you should be seeing 12.5-13.0's

Well Adam

There are several ways to tune and I'll share a thought or two with you

WOT tuning is walk in the park compared to Closed Loop tuning :Word:

In the self tuning world ... THAT seperates the men from the boys

Honestly ... I never found wideband data to be all that helpful when tunning
for CL

I pretty muchly used KAMRF & LAMBSE readings in my datalogs to tell me
what was going on and tuned from there

We all know the CL part of your tune is contained in the lower half of the meters t curve

In a nutshell ... I found once I got my CL part of the tune stable and
dermined where the cut over point of the t curve (point between CL & OL)
was ... I then tuned for WOT using fuel tables and upper part of the t curve
to arrive at desired af ratios

If this concept draws some interest
we might wanna start a new thread in tuning so as not to hihack the op's
thread here

Grady

 

[bayellowstang]

OT I would love to talk some more about this Grady.

Back on topic I have the xcam using a twEECer and Binary editor to tune with. I need to weld a bung in for my LC1 so have been using kamrf to tune low end like grady was talking about. But I can never seem to get idle rich enough.

Went to the track yesterday for the first time in 3 years and the car went .5 second slower(in the 1/8) then before so I have something screwed up now. I have way to much gear to run the quarter have to shift into OD at 1000ft or run 4th to 6700 and it starts to break up at 6200. Trapped 104mph in 4th and 95mph in OD.

 

[final5-0]

OT I would love to talk some more about this Grady.

Back on topic I have the xcam using a twEECer and Binary editor to tune with. I need to weld a bung in for my LC1 so have been using kamrf to tune low end like grady was talking about. But I can never seem to get idle rich enough.

Went to the track yesterday for the first time in 3 years and the car went .5 second slower(in the 1/8) then before so I have something screwed up now. I have way to much gear to run the quarter have to shift into OD at 1000ft or run 4th to 6700 and it starts to break up at 6200. Trapped 104mph in 4th and 95mph in OD.

OK Steve

I'll be happy to share some ideas that worked for me

Notice I talk in the past tense here

Truth be made known ... I ain't done any tuning in YEARS

I've forgotten quite a bit probably more than I ever knew
and
The software has changed a WHOLE BUNCH :Word:

I can most likely remember the main points
therefore
My input would only point you in the right direction

So ... I guess you would be the judge about if I can be of any help

Yes ... For WOT you need to know for SURE several things

wideband is accurate
wideband output is synced with the rest of the data in your dlogs

Sounds like you are getting things setup for all that

Grady

 

[stangbangerrick]

Here's the low down have a 1995 gt with a 331 stroker. Got it dyno tuned and it ran great for about 2 months. My tuner said there's nothing wrong with the tune. My friend and I tested it with a LM1 with the chip out and with it in and it was running lean at WOT. Just changed about everything and checked everything. Put in a new electric fuel pressure guage so I could keep an eye on the pressure when I drive, changed the TFI and Computer checked timing. Well the fuel pressure guage is set at 40psi with the vacuum line off and hose pluged. The car was running ruff and with did a vacuum check and it was ok. With the car running at idle we shot a little starting fluid into the vacuum hose that is connected to the air intake tube located by the oil fill tube and the idle smooth out and it ran real nice. I turned off the car and we hooked up the LM1 and started the car and let it come up to temperature at idle and the A/F ratio was 19, shot in a little starting fluid and idle smooth and A/F 14.7. and then back to 19. Pulled the vacuum line off the fuel pressure regulator and had to adjust the fuel pressure to 50 psi before I could get a 14.7 A/F ratio at idle. That being said I would have to set the pressure close to 60 psi in order to have a good A/F ratio at wot. Have not put the SCT chip on the new computer. Have 255lph pump and changed the fuel filter when I put the pump in last spring. I'm thinking that the fuel pressure guage is bad, or fuel regulator, maybe the MAF. What I need to know what are you guys/gals doing to make your 331/347 run when using the stock computer yea I running a Ford X303 cam. This car has always run lean. I need to fatten up the fuel ratio without all that pressure. If you look at my profile you will see a list of my mods. This car needs help!!

Well been talking to Willie at dirtydirtyracing.com and I put the SCT chip in the new (remanufactured) computer I got Friday from NAPA and the above testing was done on the computer prior to installing the SCT chip in the new computer and long story made short the car runs much better. Had to bump up the fuel pressure to 50psi to get the ratio to acceptable levels, need to take it back to the tuner so he can tweak the chip for the new computer and the fuel pressure will be back in the 39-41psi level again.