Flooded TBI: result of new fuel filter?

[ccarley]

The rain stopped this afternoon, so I finally got a chance to get under my Sub to change the fuel filter. A good thing to do I figured, since I hadn't done that since I bought it last year. It looked pretty crusty too, quite possibly original with 160k miles on it.

Installed new fuel filter, checked for leaks, and fired it up. Checked again, no leaks, sweet! Then, after a couple of minutes, it dies? I try to fire it back up, and it kind of chugs and dies, sounds flooded? So I floor it, it raps & snorts and finally clears out, and runs fine...

Could that be a symptom of air in my fuel line? Or do I just have the normal Gremlins at work under the hood?

Clay

 

[ccarley]

Sooooo after searching the intarwebz, I've found that I may have a bad engine temp sensor...

Every post that google shows me about flooding mentions the coolant temp sensor; the other symptoms "they" report are similar to my symptoms as well... but my symptoms are not as severe as what "they" say.

I'm headed to Autozone and/or O'Reilly tomorrow anyway, so I'll just pick up a new sensor while I'm there.

I'll keep you updated...
Clay

 

[dremu]

The fuel line is fairly long, so yeah, air in the line, as caused by replacing the filter, would cause starvation up front. If you really mean over 100 seconds, though, for "a coupla minutes", I don't think the line holds enough fuel that it would run for that long before the bubble made it up front and burped itself out.

You may be overthinking this, however: Was this a one-time occurrence, or is it still chugging and dying intermittently?

Rohnert Park, hmm. Why am I seeing a bumper sticker that says "USE AN ACCORDION / GO TO COTATI"

-- A

 

[sweetk30]

also temp sensor in the INTAKE 2 wire plug feeds computer. NOT the sensor in the head 1 wire that does the gauge

and i always try and blow threw a used fuel filter it will tell you a lot of info.

if you cant blow threw it even a little you have a vary old filter/vary dirty system/bad gas station place if pluged super quick from new filter to pluged.

and if the system has been trying to push threw a pluged filter for a long time be on the look out for a possible fuel pump soon as it will now spin faster/and much less restriction and can go bad. seen it before.

also if you can and it was a pluged filter or real close then do a big favor and change the filter again in a few houndred miles . you would be amaized what will still be in there.

 

[ccarley]

Thanks for the info guys!

Indeed, there had been a minor issue, which I thought was just a Gremlin showing his head from time to time. The problem was so odd that I figured I'd wait until it got worse:

I would fill up with fuel on the way home, and the next day, heading out, usually as the engine was warming up, it would hiccup pretty badly; if I was driving, it would continue running, however at a stop, it would die, but restart just fine...

The old filter was easy to blow through; it looked like there might be a check valve in there? If there was, it was wide open on the old one. Perhaps it was just the outside that was crusty.

Ahhh yes, accordions & Cotati. Are you in the area, dremu? Or just been through before? Cotati is my backyard

Thanks as always for the wisdom SweetK30, I'll be sure to change the filter again in week or so just to be sure.

Clay

 

[dremu]

I would fill up with fuel on the way home, and the next day, heading out, usually as the engine was warming up, it would hiccup pretty badly; if I was driving, it would continue running, however at a stop, it would die, but restart just fine...

Ahhh yes, accordions & Cotati. Are you in the area, dremu? Or just been through before? Cotati is my backyard

East Bay, but drive through on the way to my folks in Mendocino, etc.

This only happens when the tank is full? Wonder if it's the pump acting odd ... my experience with TBI trucks is limited, but I do recall that the second time you R&R the pump, you end up cutting an access hole in the floor above it, so you don't have to drop the tank. Especially the 43-gallon Burb tank is a bear to drop, even if you use an ATV jack like I do.

-- A

 

[ccarley]

East Bay, but drive through on the way to my folks in Mendocino, etc.

This only happens when the tank is full? Wonder if it's the pump acting odd ... my experience with TBI trucks is limited, but I do recall that the second time you R&R the pump, you end up cutting an access hole in the floor above it, so you don't have to drop the tank. Especially the 43-gallon Burb tank is a bear to drop, even if you use an ATV jack like I do.

-- A

It's quite possible the pump could be on it's way. I am willing to bet the maintenance plan of the previous owners was fill with gas & change oil. Oh yeah and keep it detailed.

It's possible that I only noticed the Gremlin after filling up because of temperature as well; I would normally head to work in the early hours of the morning when it was cold out. Friday evening I'd fill with gas, and Saturday morning head out later to go mountain biking.

I'll keep the fuel pump in mind for sure!

Clay

 

[ccarley]

I replaced the CTS (coolant temp sensor) on the intake yesterday, and we took a drive out to the beach (even though the weather was "icky"). I was a tad nervous; first time our baby rode in the Suburban!

It drove great, had decent enough power (as usual) to get up the hills in 3rd. Temp gauge reported a good steady temp, and the engine seemed to run smoother than it did before. When we were leaving, and the truck was idling, it seemed like the computer was trying to see how low it could idle, and pick it back up again. The wind was cold out there, so the temp must have changed; perhaps the coolant in the radiator got cold while sitting there, even though the engine might still have been warm, and once the computer saw the cooler fluid, may have tried to make it run different.

Otherwise, the drive was just fine, as far as the engine running is concerned. I'm still thinking of replacing the fuel pump before we take it on a big trip though...

Clay

 

[Fordum]

Sounds like what ever the heck is the GM version of Ford's Idle Air Control Motor is sticking and needs cleaning.
Some one will chip in and come up with the correct name.

I have about an hour and a half to go until this damn tooth either gets pulled, drilled, reamed, or whatever and I will be able to think straight again.

 

[ccarley]

Ohhh that could be too... I'll check that out as well.

Good luck with your tooth!

Clay

 

[Fordum]

Yep, the computer uses that to control the idle. If it is physically sticking, the computer commands a small move, nothing happens and the engine continues going faster or slower.
Then the computer commands a bigger move because things have progressed, and suddenly the motor moves and its now too far and so the engine almost dies.

I have seen it on Fords many times. Usually I pull it off, give it a shot of carb cleaner and it does fine.


Just go back from the dentist, feeling fine. Got my first ever root canal. So far so good.
He has given me scripts for painkillers, and I will fill them, but we will see how much I need.
Pain and I are old friends.

 

[496truck]

When we were leaving, and the truck was idling, it seemed like the computer was trying to see how low it could idle, and pick it back up again. The wind was cold out there, so the temp must have changed; perhaps the coolant in the radiator got cold while sitting there, even though the engine might still have been warm, and once the computer saw the cooler fluid, may have tried to make it run different.

Clay

Good thought but you're thinking too far into it. The actual coolant temp doesn't differ that much throughout the system and won't effect the idle speed like you describe. Typically when the GM TBI IAC fails it fails in a high idle position, it doesn't fluctuate. Common issues for idle fluctuation are a bad EGR or EGR solenoid or both, vacuum leaks either through vac lines or TBI gasket or intake gaskets, fuel pressure issues whether it's a bad pump or bad pressure regulator, etc...

When I start mine cold it will fluctuate a bit till it warms up, then it smooths right out and drives normal. I've gone through pretty much everything, only thing left would be a new fuel press regulator. Gonna try that soon.