Fuel gauge affected by temperature
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H-T White Ops
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Fuel gauge affected by temperature
1988 CRX HF with D16Y8. Wiring outside of engine harness and ECU wiring is stock.
Gauge tested fine a few months back.
Fuel gauge reads FULL almost all the time. On occasion it will read the actual level. It seems to only read the actual level when the car/weather is cooler.
I'm assuming this is a sending unit issue, but I'm curious about why the temperature seems to play a roll.
(My car also apparently has a 10.6 gallon tank but will start cutting engine power through turns at about 8.5 gallons.)
Gauge tested fine a few months back.
Fuel gauge reads FULL almost all the time. On occasion it will read the actual level. It seems to only read the actual level when the car/weather is cooler.
I'm assuming this is a sending unit issue, but I'm curious about why the temperature seems to play a roll.
(My car also apparently has a 10.6 gallon tank but will start cutting engine power through turns at about 8.5 gallons.)
Re: Fuel gauge affected by temperature
It's probably the sending unit. Probably clogged or something. I don't remember exactly how it reads. But I know you can shift the gas enough to where the pump isn't extracting enough. I would replace the sending unit on the tank. May need a new fuel pump if you are losing power in the turns. I know my guage reads lower on some turns, but that's all.
Thread Starter
H-T White Ops
Joined: Feb 2004
Posts: 17,603
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From: USA
Re: Fuel gauge affected by temperature
Mine reads FULL almost all the time. Can't say I noticed it moving around in the turns for the past few months at least (duration of the reading issue).
I'll order the sending unit and get that figured out first. Hope Honda stocks it because O'Reilly doesn't.
I'll order the sending unit and get that figured out first. Hope Honda stocks it because O'Reilly doesn't.
Thread Starter
H-T White Ops
Joined: Feb 2004
Posts: 17,603
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From: USA
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Thread Starter
H-T White Ops
Joined: Feb 2004
Posts: 17,603
Likes: 22
From: USA
Re: Fuel gauge affected by temperature
From what I understand the fuel tank must be dropped to remove the pump, but not for removing the sending unit.
*The DX and Si have different assemblies and the HF sending unit is no longer available from Honda. Also not available from Autozone or O'Reilly Auto Parts.
I'll test everything again and post the results asap. Might be a couple days. I think I had some odd ground concerns back there on the sending unit wiring before.
Re: Fuel gauge affected by temperature
The fuel pump on the '88-'91 CRX HF is on the backside of the fuel tank and the sending unit is under an access cover beneath the personal trunk.
From what I understand the fuel tank must be dropped to remove the pump, but not for removing the sending unit.
*The DX and Si have different assemblies and the HF sending unit is no longer available from Honda. Also not available from Autozone or O'Reilly Auto Parts.
I'll test everything again and post the results asap. Might be a couple days. I think I had some odd ground concerns back there on the sending unit wiring before.
From what I understand the fuel tank must be dropped to remove the pump, but not for removing the sending unit.
*The DX and Si have different assemblies and the HF sending unit is no longer available from Honda. Also not available from Autozone or O'Reilly Auto Parts.
I'll test everything again and post the results asap. Might be a couple days. I think I had some odd ground concerns back there on the sending unit wiring before.
Thread Starter
H-T White Ops
Joined: Feb 2004
Posts: 17,603
Likes: 22
From: USA
Re: Fuel gauge affected by temperature
Thread Starter
H-T White Ops
Joined: Feb 2004
Posts: 17,603
Likes: 22
From: USA
Re: Fuel gauge affected by temperature
Okay. Got some time today. Car was definitely acting weird during some of the tests. I repeated the tests to make sure I was getting reliable results which could be replicated.
The instructions for the test:
Connections used here are the 3 pin on top of the access cover, the ground bolt coming off of just after that plug, and the 2 pin under the access cover.
Here are my test results.
So I got it to be predictable at least...
And now it's back to not wanting to fall! Lol wtf?!
The instructions for the test:
For a quick test of the gauge and circuit, remove the access cover (underneath the lockbox behind the seats) and you'll see a 2-pin connector right on top. This is the fuel level sender, unplug it. With the ignition switch ON, attach a jumper wire between the two spades on the plug, and the fuel gauge should start climbing towards full.
Here are my test results.
Code:
2p disconnected, ignition on II. Continued reading FULL. 2p and ground bolt disconnected, ignition on II. Continued reading FULL. 2p and 3p and ground bolt disconnected, ignition on II. Continued reading FULL. 3p and ground bolt disconnected, ignition on II. Continued reading FULL. 2p and ground bolt disconnected, ignition on II. (This test was already done.) Gauge falls. 2p disconnected, ignition on II. (This test was already done.) Gauge falls. At this point I realized I didn't have a jumper wire in the car so I took the keys and went to get a jumper. Come back and put key in, turn to II. Paperclip jumped across sending unit plug causes gauge to rise. Remove jumper and gauge does not move... it was falling earlier in that state. At this point I confirm that there continuity between the two pins on the 2p only when the ground bolt is connected. I disconnect the ground bolt again. I sit for awhile with the ignition on II waiting for the gauge to fall. Suddenly the gauge starts falling again. I connect the ground and the gauge still falls. Jump the 2p and the gauge rises. Remove the jumper and the gauge falls. Plug the 2p in (to the sending unit) and the gauge rises reliably.
And now it's back to not wanting to fall! Lol wtf?!
Last edited by NOFX; Sep 23, 2013 at 08:41 PM.
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