stangtrader

iTrader: (2)

Anyone have any info on getting the fbody clusters fuel gauge to work with a foxbody sending unit? I have all my wiring but that figured out for my swap.im using my 98 fbody harness/pcm/gauge cluster.I know its been done but there seems to be no info on it out there.i do still have my fbody parts car as well,would it simplify it to modify the fbody sender to the mustang?
Thanks

itsslow98

iTrader: (18)

I wish I had more info but when I was doing mine it wasnt a priority. From what I gathered the output was completely different in the mustang then the fbody so my plan was to just buy a cheap aftermarket gauge.

69 Ghost

I just responded to another thread on this. You can program the PCM to output whatever you need to show the proper level. The 98 PCMs are easier since they already have a fuel level output. What you need to do is wire the gauge through the pcm then program the output level to what you need.

stangtrader

iTrader: (2)

Heres a question maybe you can answer then, do I need the 5v ref off the c210 connector? I obviously need the signal in and out off that connector but the reference has me confused.im assuming under the table in hptuners I just enter in the ohms resistance of the ford sending unit?
Thanks

69 Ghost

If memory serves me right the sending unit uses 5 volts which is correct. The PCM in return reads milliamps (ohms law). It is your output from the PCM that drives the fuel gauge. I ended up using a 0-90 ohm sending unit -the original and a 0-90 ohm gauge. I converted to a 04 GTO PCM and OS and it is a bit different because they added another table to control the output. I had to have that table added and turn on the fuel output switch. This was done in Tunercat so there may be slight differences. The 411 PCM did not need the second table it only used the first which is ohms to gallons. In the future I will be using a newer pump/gauge setup that reads 40/240 with my fuel gauge still being a 0-90ohm unit. BTW I do have all the pinouts to convert along with the connector info for a 98 car harness converted to use the 04 PCM. PM me if you need it it could help you out.

stangtrader

iTrader: (2)

What your saying makes sense.im confused because the ford sending unit uses two wires(ground & signal), now what I was thinking is I use the signal wire off the c210 and connect to the factory fox signal wire,which leaves the 5volt referance un used because there is no where to put it.or am I mistaken and the signal wire should go to the ground lug on the unit and the ref to the signal wire on the sending unit? Sorry I cant make much sense of this wiring isn't something ive been good with understanding.
Thanks for the offer on the pin out.i may cross that bridge at some point but for now I already have alot of credits tied up on this pcm.
Thanks joe

69 Ghost

The 5 volt reference goes to the signal and the ground will just be the ground. If you look at say a standard GM sending unit it is grounded so there is only 1 wire which is the signal. Hope this makes sense.

LILHEMI

in for future reference.

Vcious04

iTrader: (16)

GM PCM's recieve the info from the fuel sending unit directly. That signal is converted by the PCM and sent output thru a serial data wire (1 wire) along with other gauge reading such as coolant temp to show correct readings on cluster which then can be changed via HPTuners and such. Stock fox body fuel gauge is basically power and ground to show fuel level. I used an aftermarket gauge on mine.

Good luck.

stangtrader

iTrader: (2)

Ok cool thanks for clearing that up,one thing tho so others looking at this 98 fbody cluster does not use serial data.98 is a odd ball animal.
Thanks again guys

69 Ghost

OK 1 more time. In the 99+ cars the dash uses a serial signal to control the fuel level sensor. The Express Vans and I believe some trucks use a separate fuel level signal from the PCM. You can program the PCM to send the fuel level output to your fuel gauge regardless of what your sending unit or fuel gauge units use there should be no need for an aftermarket gauge if done properly. Do a search on Fuel Level Segment swap for the programming system you are using, TC, EFI, HPT.

Vcious04

iTrader: (16)

The segment swap you are reffering to adequates to 2nd tank adjustments as it is a different size than primary tank. Any values +- can be entered along with fuel tank capacity to make the gauge read whatever you want.

HOWEVER,

What the OP is asking, "How to make stock foxbody fuel tank sending unit work with f-body fuel gauge". That has nothing to do with your fuel segment swap. Fox body use's a standard power and ground to adjust the "banana" gear voltage to a gauge.

stangtrader

iTrader: (2)

ok bear with me here,this is what confuses me.so basiclly what your both saying is the 5 volt refernce wire off the c210 connector will go to my sending unit for the signal,then the signal from the pcm goes to the guage cluster.and the the sensor is grounded like it is normally.but then im still left with a another fuel level signal wire thats supposed to go to the sending unit?
if thats how its supposed to be done so be it and that makes it easier.i think the extra wire and looking at the fuel gauge output vs level table in hptuners has me confused,and id also think from looking at my 98 sending unit that id need to un ground the wire and hook up the extra signal wire.
thank you guys for trying to help my understanding of this.

stangtrader

iTrader: (2)

i think i just found the needed info that explains how to get the gauge to work.i looked up the phr ls1 swap article and skimmed threw and found this and heres a link:
http://www.popularhotrodding.com/tec...t/viewall.html

"To eliminate this mess, we installed a gauge cluster from a Camaro Z28 into the Mustang's dashboard. Because the speedometer, tachometer, and most other gauges are fed data directly from the PCM, we knew it would be more accurate than the Ford gauges. The only gauge that needed modification was the fuel level, which required switching from measuring resistance through ground, to measuring resistance through 5 volts positive. We simply disconnected the grounded end of the sender, ran the 5-volt positive signal wire to one end of the sender, and connected the other end to the signal input at the PCM. The Ford's fuel-level sender reads 0 to 90 ohms.


Meanwhile, the Camaro sender used to read 33 ohms empty, and 240 ohms full. Luckily, the PCM acts as the fuel-level gauge buffer and calibrator, so you can recalibrate the gauge by programming it with EFILive or HPTuners."

N20neenee

iTrader: (3)

The PHR article is a dead end. Vinnie Kung never got it to work before he sold the car, but he made it sound like it was super easy. Im going use the Fox guages/senders and use a GPS speedometer

stangtrader

iTrader: (2)

hmm thats good to know.i thought i read some where he got it to work and that it worked great.in theory it should,seems like you just need to change the settings in hpt. i pulled my fbody sender out of the parts car. i think for the ease of everything i am just going to modify and swap the electronics part on to the fox sender and run the two wires.seems like the easiest route at this point

cam

iTrader: (9)

Anyone have a screen grab handy for which tables to tweak in HP for the level sender? Ive done the sending unit swap in the past and run direct from the tank to gauge and no issue. Trying to do more digitally now LOL

TDMKR496

iTrader: (3)

So was the problem with the PHR car with getting the PCM mapped correctly, or getting it to work with the Ford sending unit??

TDMKR496

iTrader: (3)

Anyone??

LILHEMI

im using the stock f body sender that i fabbed onto the stock mustang sender assembley. youll have to shorten the arm to get it to work in the stock location but itll work just fine. then its just a mater of running an extra wire.....