fixing the fuel sending unit

First off. GM Canada has changed its policy with the fuel sending unit (FSU). They will not repair the FSU under warranty under any circumstances now. As I was told "you are on your own". Even though the FSU is one part with the fuel pump, now the FSU is not covered under the powertrain warranty. This policy has changed since december.

So I called Merlin at St.Charles Isuzu to order one for my 2000 rodeo ls and I found out that the FSU is made specifically for the 1999 model My 2000 rodeo pcm would have to be reprogrammed and even after the reprogramming St. Charles Isuzu has had customers return with complaints. So they only change the FSU on 1999 models only. All other models they replace the whole fuel pump.

So my questions are

1) Has anybody replaced their FSU successfully on 2000 and later models? Did you have to reprogram the pcm

2) Can my currently damaged FSU be removed and repaired (say clean contacts or tweak something)

I'm cheering for #2

John

I had my FSU replaced about 3 or 4 months ago at the dealership. It cost me about $400.00 bucks.

I'm interested in this as well. I have a 2000 and aI have the FSU sitting on the shelf from St. Charles waiting to go in. Would hate to go through all that work to continue to have problems.

suvguy


First off. GM Canada has changed its policy with the fuel sending unit (FSU). They will not repair the FSU under warranty under any circumstances now. As I was told "you are on your own". Even though the FSU is one part with the fuel pump, now the FSU is not covered under the powertrain warranty. This policy has changed since december.

So I called Merlin at St.Charles Isuzu to order one for my 2000 rodeo ls and I found out that the FSU is made specifically for the 1999 model My 2000 rodeo pcm would have to be reprogrammed and even after the reprogramming St. Charles Isuzu has had customers return with complaints. So they only change the FSU on 1999 models only. All other models they replace the whole fuel pump.

So my questions are

1) Has anybody replaced their FSU successfully on 2000 and later models? Did you have to reprogram the pcm

2) Can my currently damaged FSU be removed and repaired (say clean contacts or tweak something)

I'm cheering for #2

John

.......2) Can my currently damaged FSU be removed and repaired (say clean contacts or tweak something)

I'm cheering for #2

John

Sure can. You can bend the 'wiper arm' contact back against the circuit board. These two parts loose contact with each other ( the mating surfaces wear) over time causing the sporatic fuel gauge readings. From what I understand, the same thing will happen again every 30-60000 miles, with a new or 'adjusted' FSU. There are write-ups on this floating around either here or planetisuzu.
G/luck
Joel

I'll add this bit of info to the FAQ's....

What's the part number for a 2001 Rodeo? I clicked on the St Charles Isuzu but it took my right back to the FAQ page.

This is an older post, but I figured it might help someone Googling.
I have a 2006 Trailblazer with only 36k miles. For the last 10k miles, I had been getting poor mileage (17 - 18 mpg Highway) and I was told - normal for this truck. Also, it had been to the dealer several times for check engine lights, sputtering, injector cleaning etc. At 36.5k miles, the fuel gauge started acting erratically... Full, totally empty, and everything in between within seconds. Engine sputtering, check engine lights, etc. Was diagnosed as FSU. Since I was outside of warranty by 500 miles, Chevy told me that it was not covered by the warranty... Parts cost $130, but dealer p&L was close to $500... I went the route of cleaners, etc... did not help. Honestly, I was close to trading the truck due to reliability and poor mileage...

After a little armtwisting, GM agreed to replace the fsu free of charge as it was so close to being within the warranty.. the minute I got it back from the dealer, I noticed a jump in the responsiveness, performance... my mileage is at 23-24 highway.... where it should be.

Lesson learned... fsu is not just a fuel gauge sender... apparently, its issues caused the engine to go into a limp mode. Dealer tech said that it was common and issues had nothing to do w sulfur deposits..

My advice (from experience), if you are having issues and are within warranty, jump on it... i was told that replacing the unit yourself was not advisable... have to remove braces and take down the tank.... can be dangerous and is not for the rookies.

Sure can. You can bend the 'wiper arm' contact back against the circuit board. These two parts loose contact with each other ( the mating surfaces wear) over time causing the sporatic fuel gauge readings. From what I understand, the same thing will happen again every 30-60000 miles, with a new or 'adjusted' FSU. There are write-ups on this floating around either here or planetisuzu.
G/luck
Joel
Although this is a mighty old thread . . .

Sure hard for me to see how. I changed mine recently & the variable resistance contact was burned almost down to a nub. Hardly anything left to bend. I simply replaced the entire pump since it had 110K miles & I was hoping not to have to drop that tank again for the remaining term of my ownership. No ECM re-flash required in my case.

http://www.supermotors.net/vehicles/registry/media/664909http://www.supermotors.net/vehicles/registry/media/664909
http://www.supermotors.net/vehicles/registry/media/664909

I'd love to see those pics if you could get them to work.

Not sure how long bending them would last. The sulfur reacted with the metal of the contacts allowing them to wear quickly. I would think the effects of the sulfur would still be there. Should not be a problem with new FSUs since the epa mandated much lower sulfur levels in gas starting in '06.

Here are some pics of my old FSU vs. new..

http://www.geocities.com/gizmo_42/jpgs/oldfsu.jpg
http://www.geocities.com/gizmo_42/jpgs/newfsu.jpg

Thanks!

I tried to post the pic of mine, but cannot get the photo attachment function to work for some reason.
http://www.supermotors.net/vehicles/registry/media/664941

so let me get this straight.. that thread stickied about the FSU, is that what you got? Anyone buy a FSU from there? I just bought one for my 1999 model, will i have issues or no? Well.. if you bought it from that sticky then i guess my last question will be answered.:tongue:

Techron fuel system cleaner said in a press release that sulfur in fuel was corroding or otherwise messing with the senders and causing that problem. Techron has been refomulated to address that problem.

for those who want to know, my fsu was burnt out too, a new fsu can be bought on ebay for 35 bucks if you know how to put it in....however when i pulled out the fuel pump there was a hole in the hose too so I just bought an all new set up at kragen for 161$ !!!! pump, filter,float,fsu.... everything and has a 1 year warranty. the tank was pretty easy to drop.

don't go spending 350 on just the fuel pump, go to kragen! hopefully you can find someone to put it in cheap.

as far as bending th eold ones down to make contact...verry if'y :shakehead

the arms are so short and frayed looking after getting burned up it would be hard to bend it right and be sure it made correct contact. just get a new one. it's worth not having to drop the tank all over agin if it doesnt work.