01 Fuel Pump going out?

N

nov74fj40

Member
Anyone want to take a shot at this? Still looking for advice...

Need a pro's advice to troubleshoot this problem. Truck sits for a week and about 30 minutes in on hwy trip suddenly loses power. No hills involved, just hwy. This has happened a couple of times recently - eventually it comes back on line but is a real hazard. I am beginning to wonder if it is a fuel pump issue? Weather has been hot/humid. I currently have a check eng light - comes back emissions code. All replacement parts OEM (except shocks).

Recent fixes to 01 SR5 V6 4runner in order:

4 new bilsteins - total reset of CPU at dealer (started acting up within weeks after install)

These were done 2 months prior to issue:
New charcoal canister
New cat conv and 2 new O2 sensors
2 New emissions elect valves that allow emission flow back to intake = mounted inside fender well of DS
New plugs, knock sensors, fuel injectors, typical with manifold removal
(truck worked fine for a couple months)
Clean carb butterfly
Clean MAF

Thoughts welcomed -thanks
 
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How much gas was in it when you started having issues on the highway? I'm honestly not sure what the issue is, just thinking out loud and wondering if a hot/straining fuel pump was having issues with a low gas level on a hot day?
 
Thanks for taking time to respond. I just took if for 30 min hwy run to see if I could duplicate... no dice.

No collateral issues - just check eng light. I have noticed when filling tank with gas the gage doesn't always go to full. Have to turn turn off eng and turn back on and that usually solves problem.
 
So then what code is it throwing if you are seeing the CEL?

EDIT: If P0170 you may have a bad MAF, mine was super clean but once changed, issue went away...mine was up hills when I really noticed it though.
 
I am going to go ahead and try the MAF for starters to see what happens - it is darn near the only thing under the hood I have not changed out seems like.
 
nov74fj40 said:
Anyone want to take a shot at this? Still looking for advice...

Need a pro's advice to troubleshoot this problem. Truck sits for a week and about 30 minutes in on hwy trip suddenly loses power. No hills involved, just hwy. This has happened a couple of times recently - eventually it comes back on line but is a real hazard. I am beginning to wonder if it is a fuel pump issue? Weather has been hot/humid. I currently have a check eng light - comes back emissions code. All replacement parts OEM (except shocks).

Recent fixes to 01 SR5 V6 4runner in order:

4 new bilsteins - total reset of CPU at dealer (started acting up within weeks after install)

These were done 2 months prior to issue:
New charcoal canister
New cat conv and 2 new O2 sensors
2 New emissions elect valves that allow emission flow back to intake = mounted inside fender well of DS
New plugs, knock sensors, fuel injectors, typical with manifold removal
(truck worked fine for a couple months)
Clean carb butterfly
Clean MAF

Thoughts welcomed -thanks
Click to expand...

When you say it loses "power" are you saying the gas pedal doesn't respond or the motor actually stops. If the motor stopped, all your dash warning lights would come on and it would be hard to brake and steer.

What were you chasing that you replaced all those other parts? Where they OEM parts?
 
the "power" loss was engine would not respond to acceleration (pedal). Vehicle slowed but did not stall. All other functions worked properly. I did the changes because I was going to drive X-country and try to get through smog in Cali. It was time for stuff to be done - truck has about 200k miles.
Once strange intermittent problem was the gas guage - sometimes it will not move to full after filling - it just sits on E - doesn't register. Then turn car off and restart and it returns to F (as it should after fill up).

I was chasing getting rid of check eng light too. Still has it on and all replacements were OEM
 
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TheDurk said:
Not THAT bad.

https://smile.amazon.com/gp/product/B00274XAEK/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

With 200k, it doesn't owe you anything. Real issue is the labor. It's a pain in the ass job to drop the tank.

OP? What code is the CEL showing?
Click to expand...

Ditto. About $75, and 2-3 hours of time if you're an average Joe. I did mine back in May as preventative maintenance. It's a lot easier if you don't have to mess with an aftermarket fuel tank skid too. The hardest part for me was releasing the one connection on the check valve I think it was. I couldn't get it to release so I dropped the tank down as low as I could which gave me enough room to pull the assembly out. Swap the pumps, clean the contacts, and put the new one in with a new gasket. Fuel pumps aren't hard, but you're gonna smell like gas afterwards. Especially if you spray it all over yourself like I did. Make sure you really depressurize those lines. I underestimated how much fuel/pressure would still be in them. @Jhlems has a fantastic write up on replacing the fuel pump in his build thread.
 
Unner said:
Ditto. About $75, and 2-3 hours of time if you're an average Joe. I did mine back in May as preventative maintenance. It's a lot easier if you don't have to mess with an aftermarket fuel tank skid too. The hardest part for me was releasing the one connection on the check valve I think it was. I couldn't get it to release so I dropped the tank down as low as I could which gave me enough room to pull the assembly out. Swap the pumps, clean the contacts, and put the new one in with a new gasket. Fuel pumps aren't hard, but you're gonna smell like gas afterwards. Especially if you spray it all over yourself like I did. Make sure you really depressurize those lines. I underestimated how much fuel/pressure would still be in them. @Jhlems has a fantastic write up on replacing the fuel pump in his build thread.
Click to expand...

I did mine as PM, too, (at 170k), because I had the tank off for my frame swap. No issue on pressure, because I had run the engine with the FP unplugged until it died, since I knew it would be sitting for weeks and I didn't want fuel system plugging up.
 
TheDurk said:
I did mine as PM, too, (at 170k), because I had the tank off for my frame swap. No issue on pressure, because I had run the engine with the FP unplugged until it died, since I knew it would be sitting for weeks and I didn't want fuel system plugging up.
Click to expand...

I cranked mine for awhile thinking it would be good, but there was still a lot of pressure. I made a pretty good mess when I got that first line off... I did mine at 220k as PM. It didn't show any issues, but I didn't want it to start showing any issues either...
 
Unner said:
I cranked mine for awhile thinking it would be good, but there was still a lot of pressure. I made a pretty good mess when I got that first line off... I did mine at 220k as PM. It didn't show any issues, but I didn't want it to start showing any issues either...
Click to expand...

I also let it sit for a week before I got around to the fuel tank.
 
update on troubleshoot / symtoms

Here is what I have noticed - when I fill tank, I noticed there is never pressure when I unscrew gas cap. Gas cap is new. I also catch a whiff every now and then of gas but it is not coming from spout, smells like it is around the tank but it is not "wet" Based on what you guys have shared sounds like I need to drop the tank and start replacing pump, etc. Question, would a leak create an intermittent guage reading problem?

Thanks
 
nov74fj40 said:
Not sure on code guy in shop said "emissions". Can autozone pull a specific code?
Click to expand...

Order an OBDII Bluetooth reader off of Amazon for $12 if you don't want to spend $150 on a scangauge. You will be able to read real time codes on your phone with it and will help with troubleshooting a lot.
 
Thanks Tystaco, Unner, TheDurk

Ordered CEL reader today from Amazon. Needed one for my '98 LC anyway. Will keep you all posted....
 
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