GuLuMoNeY

hey guys. thanks for taking the time to read this and the help.

recently my car just starting shutting off on me while driving. the first time it happened i was low on gas maybe like an 1/8th of a tank left so i just assumed i was running low on gas and maybe the gauge was off. got some gas and it started fine. drove it for a few days nothing happened. took it on a 100mile trip and it started shutting off again but with a full tank of gas. (im still out of town and over 100miles away from home, its gonna be a scary drive back) to me it feels as if the fuel pump is not sending fuel and the car is struggling to stay on and then just shuts off. so while rolling on the freeway i'm turning the key to the off position then back on and hoping for it to start. so far i have been lucky and it starts but when i'm slowing down to park it will shut off and sometimes it takes a good 20 or 30 turns to get the car started again.

has anyone had this happen to them? does this sound like a fuel pump malfunction? what can i do to diagnose this issue?

any help would be appreciated. thank you all so much.

also if anyone has a fuel pump for sale or knows someone with one i would also be interested.

Gill
916-871-3719

meatyCTS-V

I would start with pulling the fuel line, when it's cranking and not starting, and see if you are getting a constant fuel flow, or if it's just sporadic.

Then from there, if it's just low fuel flow, I'd take a look at the fuel filter, if it hasn't be replaced recently.

If it's sporadic, and you've already eliminiated the possibility of it being the filter, I'd take a look at the pump.

I'm not familiar with the electronics in the Cadillac, but if there is a way to set the fuel pump on without starting the car, that would be a good way to diagnose the condition of the pump flow, or lack thereof.

You may even look to a shop that can hook a gauge inline with your fuel pump and check fuel pressure. It's the "safer" way of doing it.

-meaty

GuLuMoNeY

thank you meaty i appreciate it!

BudRacing

iTrader: (3)

Is there not a schrader valve on our fuel lines/rails somewhere? I'm new to this platform.

AAIIIC

iTrader: (19)

I'm not sure if there is, BudRacing, as I haven't had any need to look for one. If there is a schrader valve that would definitely be the right way to check fuel if you're getting good fuel pressure.

Intermittent problems like this could be so many different things that it's tough to know where to start. It doesn't sound like a fuel issue to me because of the intermittent nature of it. I could be wrong (I've never had a fuel pump go bad on me), but I would think if the fuel pump is bad, it's bad - it wouldn't work OK one minute, die the next, and then work again a minute later. Same goes for the fuel filter - it should either flow, or not flow, I wouldn't think there's any way for it to flow just fine, then choke off flow, then flow just fine again.

I assume the car isn't throwing a Check Engine Light? Even if the CEL isn't lit, it probably wouldn't hurt to go to Autozone or some other place that will pull codes to see if there's a "pending" code in the system.

Ekshail

Sounds like a fuel pump issue to me. When mine started going out in the Explorer it did the same thing you're describing. It finally gave up the ghost about a week later.

Listen very carefully when you go to start the car. You should hear the fuel pump prime before actual start up. If you don't hear it, then that's your problem. If you do hear it (and it sounds strong), then it's most likely a clogged fuel filter.

Ls2SilverBullet

My mothers Chrysler Pacifica just was going through the same thing or something similar. She would be on road trips and it would begin to shutter and vibrate and cut off. Sometimes it happened it would fire right back up. Sometimes she would sit there for 20min trying to get the damn thing to turn back on. After we experienced this a couple times we took the car up to RPM automotive by where they live to have diagnostics ran and they couldn't find a damn thing wrong.

So the car acts fine during normal driving conditions for about a week. She has to go out of town again and we have found nothing wrong with the car so we crossed our fingers and went for it. About 2 hours away from home the Pacifica shuts off and wont start back up. She had to get the car towed and got a rental. The tow truck driver refered her to someone he knew and trusted, aparantly, and they replaced both fuel pumps. $800 later the car is fine and there has not been a problem since.

Sounds like you are having the same problem, but I wouldn't jump to conclusions before testing the fuel lines tho. Hope this helps

adanieljohnson1

iTrader: (1)

Sounds like the crank sincer... did the same thing to me about a year ago!

AAIIIC

iTrader: (19)

Is a "sincer" kind of like a sensor?

Ls2SilverBullet

Exactly the same, but different.

vmapper

iTrader: (8)

if the rail is the same as the LS1, the schrader valve is on the front drivers side end, should be able to remove the rubber end.. then see the valve. I dont remember, I have FAST rails on now...

serik21

Check fuel pump but my gas would be with crank sensor I had a buddy's car do that work fine as soon as it got up to operating temps the car would die. And would be hard to start until engine got below 135 degrees it wouldn't start. Monitor your temps next time it's having that issue and if it starts on cold no problem but has a hard time starting on a warm engine 90 percent sure it's your crank sensr

adanieljohnson1

iTrader: (1)

Lol, *** off, what u expect? I drive a puke green car! Ima loud to furk up mi words foo!

meatyCTS-V

Any new information on whether or not you have solved your problem?

The only thing a Troubleshooting thread needs is a happy ending with an explaination as to what the problem was!

Don't leave us in the dark...

-meaty

adanieljohnson1

iTrader: (1)

This
VVVVVV
I'm sure its the Crank sensor though... He's prolly having issues at idle or when ingaging the clutch.. Also prolly noticed RPM spikes increasing on normal driving which sucks because it made me feel like my motor was fuked( no cracks about my LS6 foo's).. it was real speratic when it happened to me!

GuLuMoNeY

Thanks everyone for the replies, scenarios, etc! i'm no mechanic here but a friend of mine is pretty good with cars and he was monitoring the car with a fuel pressure gauge and noticed (after having the car idle for awhile) the fuel pressure dropped instantly and shut off, he tried to start the car again and there was no fuel pressure what so ever after. so its looking like its the fuel pump. the fuel pump must be overheating(which i have heard is a common gm/chevy thing to happen) so i have ordered one should be arriving tomorrow and my friend will be installing it within the next few days. i'll keep ya guys posted.

thanks again! have a great memorial weekend

meatyCTS-V

My diagnostic fee is $60 per hour, rounded up

-meaty

EdmundGTP

Interesting. I had a similar issue with a different car of mine. Ended up being the crank pos sensor. Another dead giveaway of a crank pos sensor issue is funky tach behavior, or the tach just dropping to zero (with the engine still running fine) while driving along.

meatyCTS-V

When my CAS went out on my Miata, it just shut off, no warning, nothing. Just dead. I pushed the car the two blocks home (I wasn't very far, on the way to work). Car never started with that CAS ever again. Overnighted another one, despite many people saying it was not the problem, and it was. *shrug*

I hate all these silly electronics sometimes.

-meaty

FRiCK

iTrader: (7)

Replaced fuel pump and crank position sensor. Still no fuel pressure.

Going to check for any soft codes, as there is no engine light on...

Thoughts....??