Is my fuel pressure to high and questions on Scan maste readings

[transampacecar]

Newbie trying to learn, hopefully not the hard way by breaking something.
The TTA is stock (and I would like to keep it that way, but dont mind bolt ons) except for
1. 160 degree thermostat
2. Adjustable Fuel pressure reg
3. Mild chip set for 93 Octane done by Caspers.
4. K & N filter in the stock air filter box.

I have adjusted the actuator and the boost is 17 lbs.
1. Scan master reads at WOT in 3rd gear, 864 for the 02 and 3.3 knock.
2. The fuel pressure gauge is set ot 47

I did not record yet the other readings in Scanmaster, but trying to find out if the above readings and fuel pressure is a problem.
What are any suggestions as to what I should change, upgrade, tune, etc.

Also, I just ordered a Walpro 340 and Hot wire kit, but I assume that is not going to change any of the above.

 

[mark b]

Julio & Co are more the experts here, but...

O2 is a tad rich - fuel pressure could come down a little. You should get near 780 or so I believe. However... as a newbie, it's better to be a little rich than lean. Smart move on the Walbro - get that in there and hot-wired, then start tweaking the FP.

 

[Lee_Burough]

The fuel pressure gauge is set ot 47

When the 'Experts' come back from the Buick Nationals to read your post, they're going to want to know your fuel pressure reading....With the vacuum hose OFF the top of the regulator. I'm not sure what you mean when you say your guage is 'set' to 47....Does that mean you read 47 PSI?

 

[transampacecar]

Yes, when my mechanic put a gauge on the regulator, it read 55, he turned it down to 47 with the vacuum hose on.

 

[Murt TTA]

With the vacuum line off, your fuel pressure should be between 42 and 45.

Tune the o2 numbers for 800 in the top of third gear, 864 is way rich. Bring it down to at least 810 or so.

IS the knock occuring on shift? or is it increasing knock in the top of third?

IF its on the 1-2 or 2-3 shift a few degrees is normal, just watch if it increases, or decreases.

Increasing knock is bad, decreasing, probably just false knock.

Whats your timing in your chip? If your running 18* or so you should be able to run 17-18 lbs of boost on 93 octane, give or take.

Bring those o2's numbers down by decreasing fuel pressure and watch for knock increase.

Good luck.

 

[turbota633]

slightly straying from the topic..but

reading the FP with the vac line off, as opposed to the line on, what would the difference be..readings would show lower FP with line on, or higher? also, what is the reason for reading with the line off, more accurate, i've always seen people refer to it as a "line off" reading, never really knew what it meant, now i do, but don't see why. also, what is the stock fuel pump on a TTA, curious, because i always heard that was one of the slight changes from the GN to the TTA, and while back i swear i heard it was a walbro 340, but i see people talkin of upgrading their TTA to a walbro 340, so it has me wondering. thanks in advance for edumacating me...again, hehe
-Joe

-p.s. i tried to search before i ask an already answered question, but my internet has been acting funny lately, search didn't wortk for some reason

 

[Lee_Burough]

Joe,

The stock FPR was a Bosch 237 (45 PSI). Red Armstrong says he's never seen a 237 vary more than one half pound of pressure.

If you put a pressure guage on the fuel rail and remove and reinstall the vacuum line, you'll see the pressure fluxuate every time.

I suppose at some point in the evolution of FPRs, that a standard condition for fuel pressure measurement became 'line off'. There may even be an engineering reason for it that I don't have a clue about....

Stock FP for the TTA is the same as the SY/TY pump. Slightly more flow capability than the GN/GNX. Those values are posted somewhere on GNTTYPE.org, but I don't know right off hand where they are.

lee

 

[transampacecar]

Matt
I called Caspers and they said that the chip I bought was set up for 93 octaine, 160 thermostat, 18lbs boost and 18 degrees of timing.
I will try to decrease the FP and see if that brings down my 02 readings.

 

[transampacecar]

Murt TTA
Thanks
I called Caspers and they said that the chip was set up for

160 degree thermostat
18 lbs of boost
18 degrees of timing
93 Octane

I added a couple of gallons of 104 octane to a full tank and took it out

On WOt at the top of 3rd gear, the knock went to 4.0 and at one point the 02 went to 910

At idle the scan master read

AF 30
L8 36-40
BAT 13.8
INT 131-134
BL 149
CLT 151
ATS 81
r 750-850
TPS .40
IAC 20
cc 07-250

At 45 mph cruising

AF 30-33
L8 96-129
BAT 14.0
INT 121-135
BL 112-134
CLT 156
ATS 61
r 750-850
TPS .64 - 1.2
IAC 56 - 65
cc 26 - 220

Not sure what all these numbers mean. I have to start learning fast.

 

[Murt TTA]

your BL numbers at idle are way high. You probably have a vaccum leak. Search for high BLM and you will find a post by razor on diagnosing a high BLM condition that is very helpful. You want to get your BL to around 128 at idle before anything else.

When you say this: On WOt at the top of 3rd gear, the knock went to 4.0 and at one point the 02 went to 910

What was the lowest the 02 numbers went down to, and did the knock decrease, or was it increasing as your speed increased?

910 is way overly rich. Are you getting any smoke out the tail pipes?

You should try tuning with just the pump gas, and only add octane if you suspect false knock. No reason to tune your car for 93 octane and a few gallons of 104 when your going to be driving it everyday with just regular octane.

Use the search feature, its priceless...

-Murt

 

[Lee_Burough]

Originally posted by Murt TTA
Snip....your BL numbers at idle are way high. You probably have a vaccum leak. ....-Murt

I chased a high BLM for a LONG time....When I finally took ....RAZOR's advice to hunt down High BLM's.... and checked the PCV valve, I found a non- AC-DELCO valve with too big a hole in it (causing high BLM at idle). I'd start looking for that vacuum leak by checking the PCV valve and making sure it is good and is AC-DELCO.... My PCV Valve was AC-Rochester.

The voice of experience.

lee

 

[turbota633]

also...

i don't know how much it would effect your readings, but yout tps at idle seemed a little low as well, at idle shouldn't the reading be .44-.46. and at WOT 4.8-4.9 or so.
http://www.gnttype.org/maint/basics.html

HTH
-Joe