Losing fuel pressure when hot
Thread Starter
Burning Brakes
Joined: May 2010
Posts: 840
Likes: 4
From: High Point NC
Losing fuel pressure when hot
Well, I drove my 90 L98 Vette from NC to PA last Wednesday without a hitch. Got up to my dads and found out that it needed a water pump. Since we were already going to install headers and magnaflow exhaust on it the water pump was just one of those things.
Anyway, we took two days to install the exhaust which included modifying the stock Y pipe to mate up with the Hedman headers. I had to go with the uncoated Elites.
It really ran great we drove it around town and Sunday morning I headed out towards home. It ran like a champ all the way down until I got about 60 miles from home.
I stopped to fill it up in Roanoke, VA then about 10 miles down the road I stopped at a McDonalds to get some food and when I went back out it would fire but sounded like it was fuel starved. Any throttle and it would cut off. Before I even opened the hood I sat in the car and ate my fries because I knew I was about to lose my appetite.
I had some wrenches in the back so after I let it cool for about 15 minutes I cracked the fuel lines loose at the rail. There was a bunch of air that came out before any fuel. I tried to crank it again and it still wouldn't run. So, I called the tow truck. $200 later we got in front of my house. Dropped it off the rollback and it fired right up! I wanted to light it on fire!
Last night I got out the pressure gauge and hooked it up. Got 30lbs. when I turned the key to "RUN"
Drove for about 20 minutes with the gauge at the windshield pressure never went over 40lbs. When I was heading home it started to stumble. Pressure was at about 25lbs when I shut it off in the garage.
Had to tighten a coolant line and pushed the car out of the garage to clean up mess under it. When I started it to put it back in the garage it didn't want to run again. So I got the gauge back out and it had 0 pressure. Cranked it and got 5lbs.
1 hour later still 5lbs.
2 hours later 20lbs.
This morning 30lbs.
I'm not sure if the fuel lines being 1" away from passenger side header are causing a "Vapor Lock" or if my fuel pump is toast.
Any help would be greatly appreciated!
Jeff
P.S. Carlisle was AWESOME!!!
Anyway, we took two days to install the exhaust which included modifying the stock Y pipe to mate up with the Hedman headers. I had to go with the uncoated Elites.
It really ran great we drove it around town and Sunday morning I headed out towards home. It ran like a champ all the way down until I got about 60 miles from home.
I stopped to fill it up in Roanoke, VA then about 10 miles down the road I stopped at a McDonalds to get some food and when I went back out it would fire but sounded like it was fuel starved. Any throttle and it would cut off. Before I even opened the hood I sat in the car and ate my fries because I knew I was about to lose my appetite.
I had some wrenches in the back so after I let it cool for about 15 minutes I cracked the fuel lines loose at the rail. There was a bunch of air that came out before any fuel. I tried to crank it again and it still wouldn't run. So, I called the tow truck. $200 later we got in front of my house. Dropped it off the rollback and it fired right up! I wanted to light it on fire!
Last night I got out the pressure gauge and hooked it up. Got 30lbs. when I turned the key to "RUN"
Drove for about 20 minutes with the gauge at the windshield pressure never went over 40lbs. When I was heading home it started to stumble. Pressure was at about 25lbs when I shut it off in the garage.
Had to tighten a coolant line and pushed the car out of the garage to clean up mess under it. When I started it to put it back in the garage it didn't want to run again. So I got the gauge back out and it had 0 pressure. Cranked it and got 5lbs.
1 hour later still 5lbs.
2 hours later 20lbs.
This morning 30lbs.
I'm not sure if the fuel lines being 1" away from passenger side header are causing a "Vapor Lock" or if my fuel pump is toast.
Any help would be greatly appreciated!
Jeff
P.S. Carlisle was AWESOME!!!
Burning Brakes
Joined: May 2006
Posts: 857
Likes: 1
From: Morrisonville Illinios
More than likely FUEL Pump. My sons "Z" pumps (ZR1 has 2 pumps) shot craps about a mile from home was able to nurse it home and checked the filter assembly with the line off NO FUEL FLOW!!! Not that big of a dela to replace the unit. it is all under the filler lid. as a side note we have MELROSE headers on ours and have never had a problem with vapor lock. Shop aropund for the best price and GOOD LUCK
wro87
