That was my next question. If you are not getting any B272X codes, then the VATs is working, and the BCM is satisfied. If the BCM is not providing a ground, even though it receives the correct resistance, then that suggests a problem with the wire between the BCM and the TDR, or a bad BCM.....or a BCM that has been exposed to moisture. Personally, I like to know what's wrong, and get it replaced/repaired...I don't do band aid fixes.....unless it's for troubleshooting, or temporary to get me home.

 

I said I DO know what bleed down is .... check the second link on Bills post to find the BCM B2647 ambient light code

 

The only codes present were the ones posted. I will check fuel pressure when I get a chance to work on it (12hr days ya know). Just dreading replacing the pump(or pumps) if necessary.

 

If it's the pump the engine would never run. I'll wager a nice chicken salad sandwich and a bottle of Dos Equis dark it's the check-valve built in (i.e., non-replaceable as a seperate item) to the line.

See post 13. Cereal.

 

Like the man suggested, put a fuel pressure guage on it and let it set for several hrs. or overnight and see if the pressure holds or has dropped to zero. From your description, it sure sounds like the fuel pump is leaking down. Good luck!!!

 

Fuel pump not leaking down. It's the checkvalve leaking down in the line. Don't need several hours. You can find out in 5 minutes.

 

I saw post 13 and thought I would check that out. As you said in most cases electric pumps work...or don't.

 

Hey Lonestar,

What is this check-valve and where about is it exactly? The whole section of fuel line must be replaced then?

I just like to know of any issues that may arise as I'm pushing 130K now..

Thanks,

Donnie

 

From what you're describing as the sypmtoms, I think I may have your answer.
Either do, or have done, a fuel pressure check. Engine off but turn the key on only. It should read between 55-61 lbs, and here's the key, it should stay there. If it bleeds back down rapidly, there are two possible culprits. One (and least hassle) is the fuel filter/regulator. The other is the check valve in the rear fuel feed pipe is not working, thereby allowing the pressure to immediately drop off. You may also experience the occasional lean backfire, or "pop" upon startup.
Try replacing the fuel filter first (10299146). I have a hunch it may not solve the problem, but at least you'll have a new fuel filter (and the pressure regulator that is part of the filter too) and have eliminated it as a possible cause.
What I suspect is the rear fuel feed pipe, or as GM calls the "Fuel feed rear hose". The part number is 10448899. Installing it will involve lowering the driver's side fuel tank to replace.
Last year I started experiencing the exact same symptoms. The car would always start on the second try, but it also puts double the wear and tear on the starter too.
After replacing the rear fuel feed pipe, problem solved.
As I said earlier, the inability of the fuel system to hold pressure is the giveaway here.
HTH,
This is thanks to lonestar from a post about 4 years ago! Seems like the culprit...tks Lonestar!

 

Thanks blackbeast, I'm actually not having any issues. I just wanted to know what the check valve was and where exactly it was located.

Take care and let us know if you get it fixed or not,

Donnie

 

Thks. It might wait for a winter project, seeing as how here in MN I don't have much longer to have the cars out. Seeing as how I've already replaced the fuel filter/regulator this seems the culprit, found it for about 45 bucks. It will join the C5 brake conversion and lowering of the C4 as winter projects...Thanks everyone for their Help!

 

Most likely yes, but do not forget about the injectors....which would be the third culprit. Just isolate when troubleshooting to make sure.

 

Will do! and tks for all the advise Lucky! Hmmmm wonder if I could slip by some larger injectors past the wife as something the car "needs"

 

94BB: You are quite welcome for the info. Learning from others here is what this place is all about.

Seems as though this problem crops up from time to time and usually (not always) involves '99s for some reason. Maybe due to a bad batch of fuel hose assemblies (or at least the check valve) from one of GM's vendors that year. Dunno for sure. Unfortunately, the check valve itself is made into the hose and non-serviceable separately. PITA to replace too because of the routing plus the stiffness of the hose.

I have given serious consideration to coming up with an alternative way to replace that hose without a) dropping the L/H tank or b) not dropping the tank and installing the hose and running the risk of kinking the nylon hose. It's the relative non-flexibility of the nylon that's the main problem. It could be done using 3 push-on quick connect fittings, a "Y" fitting, an aftermarket check valve, and some flexible high pressure fuel line hose like the black stuff on the market from Russell, etc. That way you could install the assembly fairly easily, without dropping the tank, and with no risk of fuel hose kinking, OR you could even buy the GM hose assembly, sacrifice it by cutting out the section with the new check valve (using a tubing cutter) and splice it into the old line using some of Dorman's nylon fuel line slice/repair fittings for a nice permanent repair. Maybe even cut/splice in an aftermarket check valve too.

Food for thought.