Stall Converter & Gas Mileage??

[Black1986Beast]

Hey, I already have a thread that has to do with the horrible gas mileage that I've gotten with my car.
I filled it up for the 1st time since I bought it..then only got about 145 miles to the tank! which = about 8 Miles to the gallon!! Now my brother thinks it's because of the stall converter (2400rpm) and I can't think of any other reason..Cuz with the stall converter you gotta give it more gas than usual to go..but I cant see how that should cut the avg MPG in half..
Any suggestions??

 

[XLR8]

I think 2400 is very close to a stock stall speed. I just put in a club orange stripe converter and get around 15 - 16 mpg mostly city driving with my foot in it all the time. I would look at your O2 sensor, air filter, and spark plugs. I only drove 2.25 miles yeasterday and got less than 5 mpg. Of course I was only driving 1/4 mile at a time.

 

[Black1986Beast]

So if I buy new plugs, an O2 sensor and a new K&N then I should see somewhat of an increase, right??

 

[Steve Wood]

If the rest of the car is in good tune and you keep your foot out of the turbo.. That means the maf, etc. all are working correctly.

 

[TurboDave]

If your new converter is a non locking type, that's where all your fuel mileage has gone.

 

[Black1986Beast]

What exactly is non-locking? And that can cause you to lose around 6 MPG?????
That's INSANE!! I replaced O2 sensor and it doesnt seem like it's helped..

 

[Chris Taylor]

Like Steve said everything has to be in tune. Your chip can play a big part in bad mileage also.

I have a Modified D5 converter that stalls around 3000 rpm. I drive my T every day and adv. 16-17 mpg and 23-24 on a road trip.

Make sure that everything is working proerly: TPS, IAC, BLM's, plugs, wires, coil pack, O2, MAF, vacuum lines etc.. Do you have a scan tool?

 

[TurboDave]

Originally posted by Black1986Beast
What exactly is non-locking? And that can cause you to lose around 6 MPG?????
That's INSANE!! I replaced O2 sensor and it doesnt seem like it's helped..

By that I mean, is your converter equiped with a lock up clutch or not? stock had a clutch for true lock up, sorta like a clutch equiped stick.
Many after market converters are designed as non lock up (no clutch).

Which is yours?

 

[GS70350]

On the way to BG this year, i got 21 mpg running at 80 mph the whole way, with the converter not locked up at all because of the sticking clutch. so, with it slipping quite a bit, i still managed 21 mpg, at about 2800 rpm. this is with the car running in pretty poor tune, with MSD 50s and a max effort chip as well, on 16 degrees of timing. so something is out of tune pretty bad on yours. around town, i get about 14 or so i estimate.
check your 02 sensor readings under cruise and see if you can lower your fuel pressure a tad. or get another chip burned that has a lean cruise mode. that helped out for me.

 

[Black1986Beast]

Yea I have a Scanmaster 2.
Let me know what my #'s in certain categories should be at idle, and then while cruising. (while cruising, please specify MPH) and I'll see if my friend and I can go for a ride and he can write down the info and we can post it here and see what you guys think.

I'll assume my converter is non-lockup..but could u go more in depth in explaining that??

Also, if you reccomend getting a chip burnt, since Testa isn't too far away from me should I drop him a line?? When you get a chip custom burnt can it be set at a boost level of your choice? (for example, can I tell him I wanna run 18PSI on the street?) Also--How Much $$ would it cost me for him to burn me a chip?
Thanks guys

 

[GS70350]

Lock up torque converters do just what they are named for. when you hit a certain speed, fluid is sent to the clutch which makes the torque converter into pretty much a solid 1:1 connection from the engine to the transmission. non lock up converters have stall speeds where they begin to tighten up and quit slipping, and begin to kinda lock up on their own, but they will always slip a bit. under lock up conditions, i see about a 300 rpm drop in engine speed from when its not locked up. so it makes quite a bit of difference.
As for the chip, Testa makes good ones. Just drop him a line telling him you want a low timing chip for pump gas and high boost, with lean cruise or whatever little things you want done. count on paying anywhere from 25 bucks for a thrasher chip, to over a hundred for some. thumbwheel chips are more. im not sure about Jim's prices though.

 

[Black1986Beast]

Ok, now I'm really considering getting a Testa chip. ( as long as I can get him to do it) but now when you replace a chip, what exactly is the process? Don't you have to do things like unplug the ECM and things like that?

Also I doubt all of this gas mileage is as a result of the chip, a chip specifically programmed for my car can't hurt, right??
What's the highest boost to run on pump gas?? 18PSI??
Thanks again, you guys are really helpin me here and I appreciate it.

 

[BLACK6PACK]

Have you checked to see if you have a gas leak? I have a 3500 rpm non lock converter and get well over 20mpg

 

[Black1986Beast]

Originally posted by BLACK6PACK
Have you checked to see if you have a gas leak? I have a 3500 rpm non lock converter and get well over 20mpg

Well it's not like I leave the car sitting and the needle is on F and I come back and it has moved..so it's not a leak while the car is off.
i'm gonna check to make sure all of my hoses are tightly clamped and stuff, too.

 

[Spoolinup]

Whats your fuel pressure line off?
BLM at idle?
BLM at 2000 rpm no boost?
WOT 02 reading?
Maf at WOT?
Maf at idle?
TPS at idle?

That scanmaster is the key here.

 

[BLACK6PACK]

I have sprung 3 different fuel leaks on my car. Two of them were where the hard line coming out of the tank switches to the rubber lines above the rear axle. Another was where the hard line switches to the rubber lines in front of the motor. Turn the motor on and check and see if you have leaks there.

 

[QuickWE4]

Jim T. now has an online form on his website to allow you to order a chip and, at the same time, record some information about your combo.

He'll recommend whatever is best for your combination, and I believe the published fee is $50.00.

Just do a member search for TurboJim and link from his profile to his website.

HTH
Rich

 

[Black1986Beast]

Results Courtesy Of ScanMaster 2

Here's the Readings at Idle:
O2--390's-400's
AF--05
L8--42.44
Bat--13.2-13.6
Int--128
GL--132
MPH--00
Clt--162
Ats--116
RPM--700
Tps--.50 (I know, I know..a tad high)
IAC--36
CC-216

Here's the readings at Approx. 2,000 RPM
O2--070, 882, 527, 648, 660, 054, etc..(are they supposed to be this jumpy??)
AF--14
L8--39
Bat--13.2
Int--121, 133, 125
GL--133
MPH--00 (I was in park)
Clt--173
Ats--130
RPM--1,975-2025
Tps-- .70
Iac--46
CC--153

So, what does this tell???\
Thanks

 

[Spoolinup]

The only time the 02 milivolts are even remotely relevant are at WOT. They are going to be jumpy at low rpm thats normal, and should not be used to tune unless at WOT.

GL is really the Block learn or BL, and 132 at idle is good.

Set the tps to .44 with the car running,

And you need a load on the car for the 2000 rpm block learn scan, so in park is not going to get it.

But what are the 02 at wot and block learn at moving rpms?

So far looks ok.

 

[Black1986Beast]

At WOT My O2's are in the 800's, but I'll hafta get back to you for the BL..