Gas tank won't fill to full. Reply #15 – October 02, 2013, 08:52:14 PM Thunder jetLike the doctor said the wires pass through the trunk however you should try to figure out a way to make the level of the fuel change so that you can take a couple or three or even four readings by resistanceI suppose there might be a connector in the trunk but I'm not sureMost definitely we need to isolate the float if you want to go that route and this is why I recommended you use the test connector to make the fuel pump run continuously you can empty it out and then add some fuel back and measure the resistance of the float and then add a little more fuel back in measure the resistance of the float so on and so forth Quote Selected
Gas tank won't fill to full. Reply #16 – October 02, 2013, 08:53:46 PM Does Kansas use a "winter" and "summer" gas blend like Illinois? Perhaps this has something to do with the ethanol content of the gas?On a side note my Mark VII does something similar. The gas pump clicks off but the needle on the gas gauge isn't at the full line. It's slightly below it. Perhaps the ethanol in the gas screws with older floats? Quote Selected
Gas tank won't fill to full. Reply #17 – October 02, 2013, 09:08:09 PM I would hate to think that our floats are starting to get full of liquid making them heavier but I suppose it could be an optionBoth of your floats yours and his would've had to of taken on the exact same amount of fluid thoughOnce upon a time a lawnmower carburetor float started to take on a little bit of gas and made it run incorrect until I Soldered it and fixed the problem Quote Selected
Gas tank won't fill to full. Reply #18 – October 02, 2013, 10:51:58 PM Mine clicks off and shows 18 or 19 most of the time. It didn't used to, but earlier this year when I switched cars and did a transplant marathon, I moved the tank to the other car (it has my Walbro 190 and there was no problems with it except that it needed a new filler grommet) and lowered it, which radically changed the stance. My variables: Tank swapped but not opened, lowered - possibly changed resting angles of the tank, and replaced the filler grommet.Sort of off subject, has anybody figured out how to stop fuel sloshing away from the pickup on hard left/left drift? Doesn't do it to the right at any fuel level, just to the left with 8 gallons or less. Quote Selected
Gas tank won't fill to full. Reply #19 – October 03, 2013, 12:07:16 AM If I stand on the throttle from a stop in my Thunderbird with about 1/2 tank or less of gas the car stalls as all the fuel sloshes away from the pump pickup :hick:. Quote Selected
Gas tank won't fill to full. Reply #20 – October 03, 2013, 08:34:06 AM Quote from: thunderjet302;422823Does Kansas use a "winter" and "summer" gas blend like Illinois? Perhaps this has something to do with the ethanol content of the gas?AFAIK, the Kansas fuel is the same year round. I think Kansas limits it to 10-15% Max. If the fuel was changing, I would think I would have noticed this before, Ive had the car here for 6 years. Im confused? Quote Selected
Gas tank won't fill to full. Reply #21 – October 03, 2013, 07:58:43 PM Here are the test procedures to enter the diagnostic mode and then troubleshoot a inaccurate fuel reading Quote Selected
Gas tank won't fill to full. Reply #23 – October 03, 2013, 08:12:28 PM full digi clusters require a sender that reads low resistance when empty, high resistance when fullclusters that are buttstuffog or only have an electronic speedo are opposite resistance readings.a snipit from my diy link below....................................==============================================Fuel sending unit infoConventional "buttstuffog cluster"87 Evtm page 127 or 129 shows Empty - resistance - 60 to 86 ohmsFull - resistance - 8 to 12 ohmsFully Electronic cluster87 shop manual 33-05-23 troubleshooting step TJ6 showsEmpty- resistance-9-12ohmsFull-high resistance - 154-160ohms88 turbo was able to verify his fuel guage was working properly. Just unplug the gray two wire connector "C491" under the package shelf accessable in the trunk. The two wires are yellow/white and a black. Insert a 10 ohm resistor in tehplug crossing the yellow/white and black wire. Make sure you have jumpered the fuel guage side of the wiring harness with this 10ohm resistor. Turn on your key and the needle should peg showing a full tank. This test was performed on a thunderbird turbo version. I wouldnt think it would be different for 3.8 or 5.0 engines but one never knows. lay on your back under the tanklook to the rightfind a two wire harnessone wire is yellow / whitethe other is likely black.this should be the sender harnessgrab harness and follow its path upit should be going up and finally under your package shelf in the trunkpackage shelf-in trunk up near speakersget in trunklook for a connector with yellow white wire and a blackunhook connectorone end goes to your dash guage the other goes to the senderdisconnect sender connectorconnect red meter lead to the yellow whiteconnect black meter lead directly to the metal tank***do not deviate from the above two steps or reading may be wrongset meter to resistance and readjot down that number you getadd 5gal of gasread senderjot down that numberif there is a change then the sender is assumed to be good.To test the guage, insert a paper clip in the connector (C491) This connector is the other end you disconnected leading to the guage turn on keygas needle will peg if its goodgas needle will peg if its a conventional clustergas needle will go to empty if its a digital cluster sendergo to my diy link below for details.go to my electrical tech sticky "1987 evtm" page 129 for wiring diagram.post your resultsYou can define what sender you have based on your readings as well as determin if it works.I have often thought that if one puts a digital cluster sender in a conventional dash car, the leads on the guage can be flipped there to compensate for the tank circuit,,,,,,,,,,(you getting this daminc?) Quote Selected
Gas tank won't fill to full. Reply #24 – October 03, 2013, 10:29:34 PM This is going to give me something to do over the winter while the car is in storage. Thanks! :) Quote Selected
Gas tank won't fill to full. Reply #25 – October 04, 2013, 11:40:09 AM so I was driving to work today. stop at a light and my temperature is pegged!but when I left for work, I also had half a tank of gas... ignore the 80mph... my speedo reads too fast dues to the 99+ mustang trans. Quote Selected
Gas tank won't fill to full. Reply #26 – October 04, 2013, 11:44:19 AM this is after cycling the key on and off and waiting for all gauges to stop moving immediately after parking the car.I'm starting to think my car wasn't overheating after all.... I always shut it down before it got into the read previously. Quote Selected
Gas tank won't fill to full. Reply #27 – October 04, 2013, 12:13:18 PM Check your IVR. I think it may be causing the pegged-gauge issue... Quote Selected
Gas tank won't fill to full. Reply #28 – October 04, 2013, 06:48:05 PM Quote from: Haystack;422919so I was driving to work today. stop at a light and my temperature is pegged!but when I left for work, I also had half a tank of gas... ignore the 80mph... my speedo reads too fast dues to the 99+ mustang trans.How the hell is it reading 84 MPH in park? Quote Selected
Gas tank won't fill to full. Reply #29 – October 05, 2013, 01:44:43 AM The indicator is clearly broken. Quote Selected
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