For those of you with Aftermarket Fuel Pumps and running out of gas at 1/4 tank!
10-05-11, 08:55 AM
#16
I know where you're going with the question, unlike others that have run out at 16 or 17 gallons because of the siphon isn't doing the work; its run completely out. When it did this, it would take the full 19 gallons. What I go by now is counting miles an listening for the walbro to start humming.
There's two 400's with swaps that I know an neither have the issue. Ones using the stock 400 pump an no SARD JPK, an the other is using the walbro 255 WITHOUT the SARD JPK. The three of us are on stock twins and I'm the only 300
There's two 400's with swaps that I know an neither have the issue. Ones using the stock 400 pump an no SARD JPK, an the other is using the walbro 255 WITHOUT the SARD JPK. The three of us are on stock twins and I'm the only 300
sounds like the temp fix is Jeff's idea. 2 extra gallon tank in the trunk!
10-05-11, 09:55 AM
#17
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Indeed, the cluster change to the TRD is the only cure I've heard so far, for those of us who have the issue, but that being said, the ones that don't have the issue since day 1 never changed clusters, so it throws that theory out the window also
10-05-11, 04:38 PM
#18
I still stand by my theory that the injector size being changed is throwing off all the fuel gauge calculations. As I said, the cars that were low boost with stock injectors had a perfectly tracking fuel gauge. The gauge would read inaccurately as soon as the injectors were upgraded, even while keeping the stock fuel pump and in tank return system just to keep things consistent.
I have a possible theory as to why the TRD cluster MIGHT be tracking accurately. Maybe the multiplex signal for the cluster is not the same as what the float and ecu is feeding. This could cause it to just read straight from the float and ignore the MAF signal stream.
My electronic fix was to see if I could trace which wire was feeding the gauge cluster the MAF signal and eliminate that. Then it would just default to reading straight from the tank float.
EDIT: Another thing, the standalone guys that either unplugged the MAF entirely or just left it dangling in the engine bay(not in the pipe) got even worse fuel level accuracy. They were the ones having the gauge dropping every 1/4 tank increments instead of tracking down smoothly. I had my MAF still in the air stream in the pipe in my standalone car and the gauge tracked accurately down to the 1/4 bottom mark.
I have a possible theory as to why the TRD cluster MIGHT be tracking accurately. Maybe the multiplex signal for the cluster is not the same as what the float and ecu is feeding. This could cause it to just read straight from the float and ignore the MAF signal stream.
My electronic fix was to see if I could trace which wire was feeding the gauge cluster the MAF signal and eliminate that. Then it would just default to reading straight from the tank float.
EDIT: Another thing, the standalone guys that either unplugged the MAF entirely or just left it dangling in the engine bay(not in the pipe) got even worse fuel level accuracy. They were the ones having the gauge dropping every 1/4 tank increments instead of tracking down smoothly. I had my MAF still in the air stream in the pipe in my standalone car and the gauge tracked accurately down to the 1/4 bottom mark.
Last edited by JeffTsai; 10-05-11 at 04:42 PM.
10-05-11, 06:24 PM
#19
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I still stand by my theory that the injector size being changed is throwing off all the fuel gauge calculations. As I said, the cars that were low boost with stock injectors had a perfectly tracking fuel gauge. The gauge would read inaccurately as soon as the injectors were upgraded, even while keeping the stock fuel pump and in tank return system just to keep things consistent.
I have a possible theory as to why the TRD cluster MIGHT be tracking accurately. Maybe the multiplex signal for the cluster is not the same as what the float and ecu is feeding. This could cause it to just read straight from the float and ignore the MAF signal stream.
My electronic fix was to see if I could trace which wire was feeding the gauge cluster the MAF signal and eliminate that. Then it would just default to reading straight from the tank float.
EDIT: Another thing, the standalone guys that either unplugged the MAF entirely or just left it dangling in the engine bay(not in the pipe) got even worse fuel level accuracy. They were the ones having the gauge dropping every 1/4 tank increments instead of tracking down smoothly. I had my MAF still in the air stream in the pipe in my standalone car and the gauge tracked accurately down to the 1/4 bottom mark.
I have a possible theory as to why the TRD cluster MIGHT be tracking accurately. Maybe the multiplex signal for the cluster is not the same as what the float and ecu is feeding. This could cause it to just read straight from the float and ignore the MAF signal stream.
My electronic fix was to see if I could trace which wire was feeding the gauge cluster the MAF signal and eliminate that. Then it would just default to reading straight from the tank float.
EDIT: Another thing, the standalone guys that either unplugged the MAF entirely or just left it dangling in the engine bay(not in the pipe) got even worse fuel level accuracy. They were the ones having the gauge dropping every 1/4 tank increments instead of tracking down smoothly. I had my MAF still in the air stream in the pipe in my standalone car and the gauge tracked accurately down to the 1/4 bottom mark.
10-05-11, 08:05 PM
#20
I still stand by my theory that the injector size being changed is throwing off all the fuel gauge calculations. As I said, the cars that were low boost with stock injectors had a perfectly tracking fuel gauge. The gauge would read inaccurately as soon as the injectors were upgraded, even while keeping the stock fuel pump and in tank return system just to keep things consistent.
I have a possible theory as to why the TRD cluster MIGHT be tracking accurately. Maybe the multiplex signal for the cluster is not the same as what the float and ecu is feeding. This could cause it to just read straight from the float and ignore the MAF signal stream.
My electronic fix was to see if I could trace which wire was feeding the gauge cluster the MAF signal and eliminate that. Then it would just default to reading straight from the tank float.
EDIT: Another thing, the standalone guys that either unplugged the MAF entirely or just left it dangling in the engine bay(not in the pipe) got even worse fuel level accuracy. They were the ones having the gauge dropping every 1/4 tank increments instead of tracking down smoothly. I had my MAF still in the air stream in the pipe in my standalone car and the gauge tracked accurately down to the 1/4 bottom mark.
I have a possible theory as to why the TRD cluster MIGHT be tracking accurately. Maybe the multiplex signal for the cluster is not the same as what the float and ecu is feeding. This could cause it to just read straight from the float and ignore the MAF signal stream.
My electronic fix was to see if I could trace which wire was feeding the gauge cluster the MAF signal and eliminate that. Then it would just default to reading straight from the tank float.
EDIT: Another thing, the standalone guys that either unplugged the MAF entirely or just left it dangling in the engine bay(not in the pipe) got even worse fuel level accuracy. They were the ones having the gauge dropping every 1/4 tank increments instead of tracking down smoothly. I had my MAF still in the air stream in the pipe in my standalone car and the gauge tracked accurately down to the 1/4 bottom mark.
I have upgraded 370cc injectors and stock fuel pump. (I have a walbro 255lph fuel pump but I havent installed it yet) Fuel gauge reads accurately till empty just like it did before the upgraded injectors. I will be installing the upgraded fuel pump soon so i'll let you guys know what happens.
On a side note, one weird thing is my stock navi (trip computer) says i'm getting close to 30mpg now, even though i'm really getting closer to 12 due to me running rich and not having my piggyback installed yet. This started happening after installing my supercharger and larger injectors. I'm not sure what the stock trip computer uses to figure out the mpg's.
Btw I have a GS430
10-05-11, 09:11 PM
#21
Upgrading the injectors just a little does not throw it off. If the size is close to stock injectors, then you won't notice too much difference. Like on a GS300 the stock injectors are 280cc, if you upgrade to 350-400cc it won't really mess with your fuel gauge much. Now, when you start doing like 550-650cc range or higher injectors is when you will start having issues.
10-07-11, 10:48 AM
#22
I just wanted to add my experience to this thread. My car as far as engine and fuel is completely stock. I have never replaced the injectors. Coils and packs are original. Spark plugs, and 90k maintenance have been done. Fuel filter was changed about 2 years ago. I only use 93 octane. Since I bought the car in the end of 2005, I have had the issue of running out of fuel at the 1/4 tank mark. I've just learned to deal with the issue and fill up my car when I approach a 1/4 but it would be great to have a resolution. Thanks in advance for any input.
10-07-11, 02:47 PM
#24
I just wanted to add my experience to this thread. My car as far as engine and fuel is completely stock. I have never replaced the injectors. Coils and packs are original. Spark plugs, and 90k maintenance have been done. Fuel filter was changed about 2 years ago. I only use 93 octane. Since I bought the car in the end of 2005, I have had the issue of running out of fuel at the 1/4 tank mark. I've just learned to deal with the issue and fill up my car when I approach a 1/4 but it would be great to have a resolution. Thanks in advance for any input.
10-07-11, 04:50 PM
#25
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GS300 here with gte vvti swap running the stock aristo ecu and stock injectors. walbro 255 pump as well.
safcII tweaked a little and i run out of gas at the 1/4 tank mark.
when i fill it's usually 16 gallons near the quarter mark.
lately i fill just under half and fill about 14 gallons.
i've run out of gas twice now and once some what intoxicated at night in a ****ty neighborhood on a hot houston night. walking 2 miles to the gas station and getting ripped off for a gas tank sucked lol
safcII tweaked a little and i run out of gas at the 1/4 tank mark.
when i fill it's usually 16 gallons near the quarter mark.
lately i fill just under half and fill about 14 gallons.
i've run out of gas twice now and once some what intoxicated at night in a ****ty neighborhood on a hot houston night. walking 2 miles to the gas station and getting ripped off for a gas tank sucked lol
03-09-12, 10:40 PM
#26
Pole Position
Has there ever been a fix for this? I was thinking of ordering a jdm cluster and swapping out the fuel gauge portion if it can be done. I have a friend stationed over in Japan that can send me one.
03-10-12, 07:40 AM
#28
I did a stock twins vvti swap for a guy a few months ago, using the stock 440's, aristo ecu, walbro 255 and I just modified the stock hanger for a return and removed the intank fpr. His fuel gauage has been working properly ever since. I warned him to pay close attention to the gauge and the gallons he is putting in but he has ended up having no issues with it. ??
03-10-12, 07:57 AM
#29
I have a possible theory as to why the TRD cluster MIGHT be tracking accurately. Maybe the multiplex signal for the cluster is not the same as what the float and ecu is feeding. This could cause it to just read straight from the float and ignore the MAF signal stream.
My electronic fix was to see if I could trace which wire was feeding the gauge cluster the MAF signal and eliminate that. Then it would just default to reading straight from the tank float.
My electronic fix was to see if I could trace which wire was feeding the gauge cluster the MAF signal and eliminate that. Then it would just default to reading straight from the tank float.
But as for the fuel sender diagram to the cluster it seems as simple as any other cars out there with the floats just going directly to the cluster.
I kinda wonder about fooling the signal going to the cluster? AMSMIKE posted the resistance readings from the senders above, so if one's gauge read off the same amount consistently and always ran out at the same mark, then would adding resistors into the sender feed raise the resistance to the point that the maybe the cluster may drop sooner thinking the float is lower than it is?
This way the cluster is going closer to empty before the tank does, although maybe still not 100% accurate but at least it may be a bit better?
Just a thought.
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