Focus Fanatics Forum banner

1 - 9 of 9 Posts

·
Premium Member
Joined
·
4,739 Posts
Discussion Starter #1
Hey guys well i got my new engine all broke in and Tom is remote tuning it but were having some trouble. for some reason from when i last went up to Toms shop on my old engine. the car is now running 28% richer. Tom thinks it may be a small vacuum leak. so i checked pretty well all the vac hoses and also ziptied all of them. the car idles smooth and on my vac boost gauge it is reading 21 vac. What do you guys think

Also heres some specs of my old and new engine

Old: Stock head, probe 9:7 pistons, eagle connecting rods, clutchmasters satge 3 clutch

New: Ported and polished head, 4 angle valve job, Supertech 8:8 comp pistons, Eagle connecting rods with esp coating, SVT block with oil squirters .007 bored.


Thanks
Jim
 

·
Premium Member
Joined
·
4,739 Posts
Discussion Starter #2
Nobody has any suggestions
 

·
Registered
Joined
·
789 Posts
vac in idle looks good. what are all of your a/f readings at idle, WOT, part throttle, and cruising? idle should be at 15.0+/- .3, WOT should be no leaner than 11.5 as long as you aren't getting any knock there, part throttle should be either the same as cruising or a little richer, 12.0 - 14.5, and cruising you should be at a somewhat steady 14.5 - 14.7. these are just rough figures so don't take them as preaching.

if the only one that is running rich is the WOT then you have three choices: 1)turn up the boost until desired a/f is reached, 2)get smaller injectors, and 3)pull some fuel back with some sort of fuel controller or with the tune.

if it is rich all of the time then you may need to check all of your sensors to make sure they are functioning properly, and if they are, then you may just need smaller injectors. the thing with injectors is they have a minimum flow rating as well, it just isn't advertised and you would most likely need to call the company to find out what it is. the computer in your car can only pull so much fuel back but if the minimum flow rating of the injector is higher than what the computer, or the tune, wants it to be then you need smaller injectors.

if you do end up needing smaller injectors, but you still need the extra fuel, i would suggest trying to fab up a return line system with a rising rate fuel pressure regulator so that you can get the extra fuel that you need to run the higher boost. i believe turbo turtle made a return line, so if you have to go this route you can talk to him about how he has his set up.

hope any of this has helped you out. i don't know how much help it will be since tom is helping you out, but sometimes even the best can get a good bead on things if they can't physically troubleshoot the problem.
 

·
Registered
Joined
·
11,906 Posts
If you had a vacuum leak wouldnt it run leaner since the engine would be drawing in more air than the MAF would be metering???

What is your TPS reading??? If is starting to short out it could be reading higher and moving you up in the base fuel table to a richer setting.... just a thought.
 

·
Vinyl + LED guru
Joined
·
4,243 Posts
I have a big issue with running really lean after installing the new fr head...at idle it's fine for a few min, then goes to 22.4 for a min, then normal,...I'm hoping to check all the sensors soon and that toms tune will help
 

·
Registered
Joined
·
9 Posts
Are you running the same tune?

Wouldn’t you not need allot less fuel running 8:8 comp compared to 9:7?

If you have not adjusted for this it could be your cause.
 

·
FF Affiliate
Joined
·
31,100 Posts
Are you running the same tune?

Wouldn’t you not need allot less fuel running 8:8 comp compared to 9:7?

If you have not adjusted for this it could be your cause.
No this wouldnt change the fuel much at all

Tom
 

·
Premium Member
Joined
·
4,739 Posts
Discussion Starter #8
hey guys Ive checked over everything Tom is going to change the tune so it will lean out a little bit back to normal and we will start tuning tomorrow
 

·
Registered
Joined
·
9 Posts
No this wouldnt change the fuel much at all

Tom
Tom, help me out.

I’m some what newish to Turbo's, but with the 9:7 compression would you not want to feed it more fuel and retard timing to stop pre-deto?
And when you drop the compression it would have a less likely chance of pre-deto and may actually not fully detonate at the most opportune time causing it to run rich?

Am I some what correct or am I just talking out me A$$?

Thanks,
Dave
 
1 - 9 of 9 Posts
Top