LT1 Intermittently Stalling

[greenformula92]

Sounds a little bit like a fuel pump issue

[FlyingDutchman]

Update:

Went to Sheetz and bought a can of starter fluid to test for spark. Hooked up the battery to a jumper since it was dead and tried to start it. Same result as last time, sort of started and quickly died, attempts after that just resulted in the engine cranking. Its like the pump builds a tiny bit of pressure but not nearly enough to continue running. Moved the intake elbow out of the way and sprayed some starter fluid in. Turned the key and it ran for a few seconds and died. Sprayed some more fluid in and it ran for a bit until the fluid was gone. It would appear there is spark.

Safe to say the fuel pump bit the dust?

[FlyingDutchman]

Called a local garage to get an estimate ... New filter and pump including the labor to remove the rear, exhaust and everything else in the way was $850 ...

So I asked, that's a top of the line pump right?

Well that's an AIRTEX pump.

Ok do you supply ACDelco or Delphi by any chance?

Well the Delphi pump itself is like $700 by itself so that would be about $1200 together.

Wow.

Rockauto has ACDelco listed at $290 ACDELCO Part # FLS1077 {#19179528}

[sweetbmxrider]

Or you could get a walbro/aeromotive/etc for under $200 and reuse your sending unit. This is also why people cut up their cars instead of remove the rear and exhaust. I would verify fuel pressure with a gauge personally and check for power going to the pump via the relay under the driver foot rest plastic. Did you try pulsing spray into the intake to keep it running?

[FlyingDutchman]

Originally Posted by sweetbmxrider

Or you could get a walbro/aeromotive/etc for under $200 and reuse your sending unit. This is also why people cut up their cars instead of remove the rear and exhaust. I would verify fuel pressure with a gauge personally and check for power going to the pump via the relay under the driver foot rest plastic. Did you try pulsing spray into the intake to keep it running?

Doesn't the walbro pump require some hotwiring kit to supply the correct amount of power? They weren't plug and play from what I read. Ill see if I can get someone to pulse spray while I crank it.

I can get a volt meter. How can I check to see the relay is transmitting power without disconnecting it?

[LTb1ow]

The fuel pump relay is under the left foot area kick panel, pull it out and verify it is clicking when you switch on the igniton. I would just pull it off, and then plug it back in, see if something changes.

You could throw a jumper lead across the connections so the fuel pump is just seeing power not going through the relay.

Otherwise, yea, a fuel pump is easy to do if you hack your car up, or a long job if you do it right. I would say a racetronix kit with the walbro is the closest and cheapest you will get to plug and play without it being a fortune.

[sweetbmxrider]

The computer only commands the pump to prime though.

Orange - Constant power from PCM BATT fuse #3 15 amp
Gray - Power feed to pump
Green/White - PCM relay command, hot when initial prime and running.
Black/White - Constant ground
Red - Fuel Pump Prime Connector. There is a stray lead by the pcm in the harness that you can jump 12 volts to and force power to the pump. If the pump doesn't run then, you can be most certain it is bad. Only other issues would be bad ground at pump or break in the circuit to the pump or ground.

[FlyingDutchman]

So it turned out the fuel pump was dead so it was replaced with a stock replacement. Thanks for the input/guidance

However, a new problem surfaced. After the mechanic had finished putting everything together he let it run for at least 15 minutes in the shop while he was doing some other odds and ends. He said the overflow tank was overflowing and the car was running hot. He said the fans didn't appear to be running. So he let it cool down and did it again with the a/c running and noticed the fans were running and the overflow tank didn't fill up. Took it for a test drive and at highway speeds (50+mph) it ran around 195*F and about 210*F around town (normal operating temps).

Drove it home last night 400miles and the temperature gauge stayed at a steady 190-200*F with no overheating issues. Although I did not just let it sit and replicate the problem.

Random event? Or possibly a bad thermostat like he was suggesting to me?

[sweetbmxrider]

Our cars are notorious for being a pain to air bleed. Try doing that first, ensuring the coolant is topped off beforehand before throwing any parts at it. The lt1's take a specific thermostat as well so make sure you get one for your application and not just a sbc one.

[greenformula92]

Could also be a bad CTS. That btw may not set an SES light. It will just give the ecm the wrong temp. reading