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Fuel tank problem

josua

Seasoned Member
Joined
Nov 13, 2016
Messages
90
Location
Gibsonia, Pa
My XLR/V(s)
2004 Raven Black xlr 2009 sts4
My last post was about #2 fuel tank. Reason I needed to know was the fuel gauge was at 3/4 full all the time {recent development). Tech II said there's a problem with #2 fuel sensor. Read the posts about Teckron additive. Figured I'd try that first. Put the big bottle in and ran the car around a few times, no luck, still 3/4 full. Decided I had to bite the bullet. Go to the caddy dealer to get their opinion and let them scan the car. They used a newer scanner and couldn't get any info (couldn't access the ECM). He said to come back when their main techie was there. Another five days wait. Show up and he's not there. Figured oh well, talked to the service mngr about changing the pump and sensor. I told him I could get the two parts and would let him know when I got them. I filled the tank before I got home and it sat in the garage for 2 days. I hadn't ordered the parts yet. Go to the garage and started the car and the guage went to full!!!. I've taken the car to work twice and the guage is working like it should. Moral of the story is, if you have this problem, don't jump the gun and have the parts changed (couple grand or more). Dump the big bottle in and give it a while. Hopefully you'll get lucky like I did. Can't imagine spending that much when it could have cost about $20. Okay, I'm done flapping my jaws. Stay safe.
 
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05 GRAND DADDY

Seasoned Member
Joined
Jun 17, 2011
Messages
2,757
Location
South Central PA (Littlestown)
My XLR/V(s)
2005 Light Platinium Silver XLR
Tank should be under half full before adding the Techron Additive as since it’s 2 tanks the second tank on the passenger still has a full tank until driven to under at least a quarter tank of gas or less then fill the tank full to mix the additive in both tanks.


Thanks
Caddy Dan using Tapatalk
 

xlrlist01

Seasoned Member
Joined
Oct 31, 2013
Messages
252
Location
HSV
Tank should be under half full before adding the Techron Additive as since it’s 2 tanks the second tank on the passenger still has a full tank until driven to under at least a quarter tank of gas or less then fill the tank full to mix the additive in both tanks.


Thanks
Caddy Dan using Tapatalk

The XLR fuel system empties the passenger's side tank first, then the driver's side tank. Working normally, the passenger tank is emptied before the driver side starts, though fuel is being pumped between both tanks all the time. This depends on me remembering that the main fuel pump is in the driver's side tank. If the main pump is in the passenger side tank, then it is the other way round.
 

IAN

Seasoned Member
Joined
Feb 19, 2015
Messages
496
Location
Province of Québec
My XLR/V(s)
2004 silver XLR
Fuel tanks

xlrist01

Actualy the passenger tank has also a siphon jet pump in order to balance the gas in both tanks

The main fuel pump for the motor is at the driver side.

When the driver gas tank is full, the level of the passenger tank is a bit less.

Enclosed is a drawing how the siphon pump works, the arrows are showing the fuel circulation in both tanks.

IAN :thumbsup

fig4c5fuel - Copie.jpg
 

05 GRAND DADDY

Seasoned Member
Joined
Jun 17, 2011
Messages
2,757
Location
South Central PA (Littlestown)
My XLR/V(s)
2005 Light Platinium Silver XLR
So the question is then, should we still lower the gas tank then at least half way or more to get gas additives mixed though both tanks? Or does this jet pump circulate fast enough to mix it up in both tanks?


Thanks
Caddy Dan using Tapatalk
 

ChicagoDave

Seasoned Member
Joined
Jun 13, 2009
Messages
1,289
Location
Lindenhurst, IL (Far North Chicago Sub)
My XLR/V(s)
2007 Black XLR V, 2005 Black XLR, 2018 XT5 AWD , 2010 Black CTX, 2007 SRX
Same thing happened to me on my 2005 Base XLR. Took a few days/a week, for the fuel injection cleaner to do it's work on the contacts, I guess. But yes, as you said - give it a few days or a couple of weeks. What do you have to lose. Be patient ... nobody wants to dumb hundreds and hundreds of $'s to replace a sensor, when some of use have resolved with a couple of bottles of the Techron fuel cleaner. Glad your problem was resolved.

Be safe!
 

IAN

Seasoned Member
Joined
Feb 19, 2015
Messages
496
Location
Province of Québec
My XLR/V(s)
2004 silver XLR
Fuel tanks

05 GRAND DADDY.

There is a regulator in each tank to stabilise the gas level of both tanks, i presumed that the car buider have figured out the sise of the siphon pump for the need of the system.

Re the guide line of the product.... it would be wise to read the recommendations on how to used it, many similars products could have different guide lines.

Clug injectors meams clug of the fuel pump, its filter and the regulators in the tanks and could not supply the needs to the motor, the idle of it could be affected and running rought.

I use in my XLR the Hi octane gas that incude the additives for the fuel system and the motor now runs smooth, it took at least 6 months to get it running properly.
My dealer have cleans the injectors that has helped.

Regular gas is economical in the first place however it could end finally to be more expensive.....thanks that there are products to help.

IAN :wave:
 

BobbyT

Active Member
Joined
Mar 6, 2017
Messages
42
Location
New York
My XLR/V(s)
2005 Black XLR
Tank should be under half full before adding the Techron Additive as since it’s 2 tanks the second tank on the passenger still has a full tank until driven to under at least a quarter tank of gas or less then fill the tank full to mix the additive in both tanks.


Thanks
Caddy Dan using Tapatalk
My 2005 XLR gauge goes to a little over half from full (after approximately 200 mile) and then to empty. Still has about 8 gallons in the tank. DIC saids Service Fuel System. Stalled out about 30 miles later. Will the Techron help with half a tank. Any thoughts would be appreciated
 

Rob

Seasoned Member
Staff member
Site Administrator
Joined
Oct 7, 2006
Messages
5,336
Location
New Hampshire
My XLR/V(s)
Not yet!
Actually, the best thing to do is let the car get near empty, pour the bottle of Chevron Techron in, and then fill up so that the incoming gas mixes with the techron in both fuel tanks.
 

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