H/C/I finally done but.....

[vladasap]

TFS stage1, ported gt40's, ported lower gt40

the car sounds and drives awesome, the popping and shaking at idle is unbelievable but the problem is it doesnt idle all that long =(

first of all, the idle drops fine until about 2000, n then hangs for a few n drops down. Then, at low rpm's when i take it out of gear, the rpm jumps to 2000, hangs n then falls back to normal again,
and FINALLY whenever i come to a full stop it surges n ....pfffttt...shuts off

ideas?? help please

other than these lil issues im really happy n the car never felt better

btw this was me when i first got it running for more than 10 secs n i heard the cam at idle --->

 

[zkillrr]

.

Sounds like a good problem to me, the rougher it idles the meaner congrats on the build and have fun !

 

[final5-0]

The first thing you wanna do is to see what all you did as nothing different from
what all Ford did when they put your motor all together

Well you used different parts ... but that is a given

By that I mean ............

Everything you touched is all back together just as Ford did it

No electrical connections left un-done
No vacuum connections left un-done

No NOTHING left un-done
or
In a state of condition no differently than when the project was started

Sounds like a vacuum leak to me

Did you run over all the lower intake bolts several times to check for even
tightness? Not doing that can result in a v leak between the head and lower.

How about a possible v leak between the upper and lower intake

Just be very thorough :Word:

and

Check EVERYTHING you touched ... which in a project like you just did ...
is everything hanging off the motor

It is gonna be something simple
and
My money is on a v leak somewhere

Grady

 

[PUNISHER RACING]

sounds vacuum related to me bud !

 

[Stanger007]

If you don't find any vacuum leaks, a tune might be just what you need.

Worked on a very similar issue today on a car, messing with the ISC values in the tune got the idle to fall nicely to commanded instead of hanging for a while and then dropping.

Wes

 

[vladasap]

ok thats what i was hoping some1 was gonna say!!!

i really double-checked everything n i cant find any vacuum leaks...anywhere...so this tuning thing
would it be sufficient just to adjust the fuel pressure and timing on a dyno OR do i have to go out n get a chip burned to get the issues outta the way???

and what exactly is the benefit of getting a chip vs. the fuel pressure n timing adjustments tune?????

oooohhh n before i forget, i put on the taller fms valve covers n now i cant fit a breather on either side of the covers cause they sit close to the manifold so i just used regular oil filler caps n sealed them shut, is this going to cause excessive crankcase pressure issues???? (i think the pcv system is original and in tact cause i never touched it)
and also i have a gauge for oil pressure n seems like the pressure is just a bit higher than usual although that might be the 20W50 oil that my mechanic recommended

 

[Stanger007]

The things I changed were items only a chip will give you. What is your vacuum at idle? This car had a TFS1 cam and was pulling 15inHg at idle, needle very steady. (we checked for vacuum leaks before tuning around a physical problem)

After the idle stuff was done we hit the WOT tuning, we added exactly the right amount of fuel at exactly the right spot, getting him to run right at 12.8 throughout his run and with 34* total spark from 3,000rpm up. By only adding fuel and spark where we wanted it, we still keep great stock drivability down low -- not too much fuel there or too much spark to cause crazy bucking.

Your dipstick will pop out if you have extra crankcase pressure. If your motor has some age on it, you may have some buildup. BUT, if you add a breather, that will be sure be a vacuum leak because the PCV will be sucking in air from the breather.

The oil pressure sounds normal to me, but see what others say.

Wes

 

[final5-0]

Several more thoughts since you feel you got NO v leaks

Stick to mechanical things you can adjust before you say nothing else can
be done to help with these issues

The isc ... make sure it is working like it should be

The amount of opening you have on the t b blade
The isc working correctly
The bleed screw

All three of these things kinda work together to obtain a stable idle

Also ... an unstable idle might be effected by ...........
Excessive spark at the dizzy
How far away from the OEM value of fuel pressure you run

Now ... these last two won't necessarily always effect the idle
but
The thing is ... they certainly can ... AND ... the bad thing about it is

If they are causing or are a part of the cause of an unstable idle .......

It will take a good while for it to happen as they cause
the pcm's adaptive strategy to compensate and that is
where it can take some time before you see the
happening occur.

If you do a pcm reset and things get noticeable better or worse .........
then
Over time ... things start to change for the better or worse

You know the pcm is trying to help
but
The amount of adjustment it needs to make ......
Well ... it may be beyond its limit of range it has to work with

One thing that can help with a cam that lopes a good bit is raising the
idle rpm up to at least 800.

You an find a T O N of threads on how to obtain a stable idle
so
Focus your search on NOT the pcm tuning stuff
but
Do focus your search on setting the mechanical stuff

Now ... This is V E R Y important ... about all this idle stuff :Word:

You want the pcm to help you
so
You need to know how to assist it in its ability to do it

Here is how I'd start the whole process

Ensure the isc is functioning correctly
Adjust tb blade
Adjust bleed screw
Reset the pcm

You gotta give the pcm enough time to get some reference points
You then gotta give the pcm enough time to make some changes

You just can't rush this process :Word:

I'd say if your Stang is a dd ... this could take a 2 or 3 days
and
A lot of how much time it takes depends upon .......
how much time you have spent at stop signs, stop lights, and the like

Now ... say you wanna make a change to find more improvement

*** Do just O N E change and O N E change only ***
Reset the pcm
Give it 2 or 3 days again to see how it goes

Make sense

btw ... that cam you used has been used by MANY peeps

I've seen some say it was not too bad without a tune
and
I've seen some say they finally gave in and got a tune

You got nothing but some time to loose with seeing how much good
you can do with the mechanical stuff is how I see it

Almost forgot ... Dump those breathers ... They allow un-metered air
Ensure the pcv valve is functioning correctly

Ensure you got a tight seal around the pcv valve as it can be a
source for a v leak that is easy to over look way back there at
the back of things.

Good Luck!

Grady

 

[Stanger007]

I would bet money you can cover up the idle problems with a higher idle... a 850-900rpm idle will cover many sins.

Grady's advice above will keep it from dying -- go for a custom tune if you want that low rumbling idle with stock or better than stock manners and the most power out of the car.

Wes

 

[PUNISHER RACING]

Is your diz. even close to #1 and TDC, what is your fuel pressure set at

 

[final5-0]

I would bet money you can cover up the idle problems with a higher idle... a 850-900rpm idle will cover many sins.

Grady's advice above will keep it from dying -- go for a custom tune if you want that low rumbling idle with stock or better than stock manners and the most power out of the car.

Wes

You know what Wes

I did want to say to start out with an idle speed of 1000 rpm to start
with ... and in fact ... I did just that once when I was starting all over
from scratch on a tune .... but ... remember I got a stick trans.

I had a concern about the auto trans boys
so
I posted less rpm than I would have if knowing a stick trans was involved

Seems like an idle that high might be a bit violent when you go from park
to drive

The last auto trans experience I had was with older C4 stuff
so
I wanted to ask you since you like the flavor of ... AUTO

How would it be with these aode transmissions
and
Using an idle kinda high like 1K

Just Curious

Grady

 

[Stanger007]

I would say that it is dependant on the person driving the car as to what they consider violent or not. On the stock tranny/tune a 1k drop into idle isn't very rough at all, especially if the car is being forced to idle higher than the commanded stock rpm by means of the ISC or TB screws.

Once you start physically and digitally messing with the line pressures you can make it jarring or gentle. But everyone with an auto has a different opinion on how they should shift. My personally, I don't like my head snapped when cruising/light throttle but I want it to shift quick when at the track. The twEECer and valvebody mods can give you that best of both worlds.

I have my neutral idle set at around 900rpm (where the S-trim really sings) and the commanded idle at 650 - the drop into gear is very smooth... you won't spill your cappuccino.

Some people run into problems dropping their auto into gear when the ISC isn't setup correctly. The calculations are off so when it goes into gear, the idle dips low and then the PCM shoots it back up to compensate and it either catches itself or the car dies trying to stabilize. The TB Airflow and Neutral/Drive idle airflows are the primary tuning areas here. There are also a good many other tables involving the transition to and from idle. It is a pain in the butt and my most unfavorite area of tuning. I'd rather be logging a wideband and doing WOT runs.

Wes

 

[final5-0]

Good info my friend

My last encounter with an auto trans was so long ago

All I remember was

A tiny tc

A valve body this guy drilled some holes in
and
Added or was it took away ball bearings

but ... Most of all

When you put it in gear or it shifted ..........
Well ... On a regular basis .......
You had to check and see if your teeth fillings were still in place

Grady

 

[Stanger007]

You had to check and see if your teeth fillings were still in place

I have ridden in those kinda cars... talk about a pain in the neck lol.

VLAD, any updates?

Wes

 

[vladasap]

well i do have a manual and i did raise the idle to just a bit over a 1000

well the idling issue went away and it doesnt stall on me at all after i did this, it was at about 850 originally when it was stalling every single time at stop, then i tried all in between n this is the lowest i could go without having stalling issues....hasnt turned off on me at all in the past two days =)

now the hanging idle started going away every now n then
it'll be running a 100% ok n then an hour later hang for a sec or two n drop again...just cant pin point out what happens or what do i do before it happens...but ill get it to it - doesnt bother me much

anyways - now that i sort of have idling and starting issues out of the way(for the most part)....theres a driving issue - i feel like the car is no faster than before - i went from a stock GT to ported cobra heads, ported lower n a cam - n it just sounds diff n the gas pedal feels great but i dont really feel much more power, if any at all

could my mechanic have retarded the timing just as a precaution??? cause he told me to come back for a "check-up after 500 miles" n he did mention something in regards to timing (but i was so excited that i didnt really listen - i know, i know- DUMB move!!)

anyways i might just take it to the cheap tuner n have him dyno it n adjust the timing n f.press. n then i might see some results .... although i really wanted to feel more power than a stock gt even w.out a tune

 

[vladasap]

i got home a lil unexpectedly n guess what i find is on my comp screen
a receipt for the 10th anniversary cobra brake kit

isnt someone in my house really sweet??? =)

***sorry for the completely random comment but it made my day***

 

[Bullitt95]

....theres a driving issue - i feel like the car is no faster than before - i went from a stock GT to ported cobra heads, ported lower n a cam - n it just sounds diff n the gas pedal feels great but i dont really feel much more power, if any at all

It's likely that you've lost some torque at lower revs with the ported Cobra heads and cam, and gained torque at higher revs (4000rpm upwards). That could be the reason why the engine feels soggy lower down.

 

[vladasap]

well i hope i gained power overall

really wanna see mid 13's =)

 

[5.0fox]

Have you upgraded your fuel pump? I ran the top end mods in my sig with a stock fuel pump and could only muster a 14.1 at the track. But with the only change being a 190 lph pump i gained 8 tenths and 7 mph. Just make sure you have the foundation to suport your mods!

 

[vladasap]

yup
got a 255 lph walbro fuel pump