Well, I drove my 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 yesterday 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 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 in there. 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!

Anyway, I haven't messed with it since it was 11:30 when I got home. But the fuel lines run about 2-3" from the right side header. Is that close enough to get them heated up and cause vapor lock or is my fuel pump weak and would a new pump help prevent this? I'm going to check the fuel pressure tonight when I get home.

Thanks for reading my long ass post. I had a few drinks last night since I was a little fired up and I'm hungover! Plus it sucks to be back at work after having last week off.

Jeff

I run uncoated headers and I have no fuel problems. It's normal to have pressure in the system if you loosen the fuel line nuts. Did you change anything else when you installed the headers? It could be related or could be unrelated. Time to start doing some diagnostics...fuel or ignition related.

Matthew

ps- I deleted the dup post.

Sorry about dup post. Not sure how that happened.

The only thing we did was the entire exhaust and the water pump.

Maybe it was just because I had been driving it for 7 hours.

When I cracked the fuel line there was a lot of air before any fuel came out.

I hope you find the cause of your problem. All I can say is my fuel line is about 3/4" from the header and there is no vapor lock.

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How full was the gas tank?

I had just filled up about 10 miles before this happened.

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Any chance they had water in their gas?

I thought about that too. I had a little over 1/2 tank and just topped it off.

If that were the case though, why would it start once I got it home?

Ok, I went out and fooled with it some tonight. Got out the pressure gauge and hooked it up. Car had sat all night since I did not want it to leave me stranded trying to get to work.

When I hooked the gauge up it had 0 pressure at the rail. I turned the key to run and it primed up to 30lbs. I tucked the pressure gauge under the wiper and went for a ride. The pressure never got above 40. After I drove for awhile it started to buck a bit. Got in the driveway and it was idling terrible. Parked it in the garage. Pressure was now reading 25lbs.
Then I found a hose clamp that I must not have tightened enough when I did the water pump and spent 30 minutes fixing that and cleaning up the mess. I rolled the car out of the garage without starting it to clean up under it. Then when I started it to pull it back in the garage it acted just like it did last night. no throttle and barely idling. I managed to coax it into the garage and hook the pressure gauge back up. There was no pressure when I turned the key during the "prime". When I tried to crank it the pressure went up to 5lbs and it won't crank. I left the gauge on it and I'm going to check it in an hour to see what it does.

Does that sound like a fuel pump? The fuel filter only has about 1000 miles on it.

What year is this again?

Look for a recent post I made in c4 tech within the last day to check the fuel system.

Matthew

It's a 90 L98 w/ 128K


Hour later and still nothing when I turn it to run.

2 hours later and now it will get up to 20lbs.

This morning it will prime up to 30lbs. again.

I will look for that post. Thanks.

No matter what you find out to be the problem, its a good idea to use some thermal tape on the gas line just in case. When I put in my 383 with headers, the first thing I did was wrap anything that looked like it was close to the headers, fuel lines, brake lines and I even put a couple layers on the bottom and side of the brake booster.. It can't hurt...WW

Ordered a fuel pump from Racetronix just now. Figure even if it's not the true problem it can't hurt.

There is a "performance" shop down the street from work so I might stop by on lunch and see what they have to wrap those fuel lines with.

Sounds like dying fuel pump. Mine would hold at 20lbs driving and when u floored it or much above 50% it would bog. THen it got worse to 25% throttle.

Changed the fuel pump and solved it all.

Dont forget to change the fuel filter at the same time

Sounds like fuel pump. How does it sound? Have someone else cycle the key while you listen to it.

I don't see how vapor lock could be happening with 40 psi of fuel pressure and the high flow rate, vs. a carb where the fuel only moves as the engine consumes it.

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On a EFI with a correctly working pump , the moment pump starts it will remove any vapor via the bypass back to the tank

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Now that makes sense of why there was so much air or vapor in the lines when I cracked them open. Thank you!

I feel pretty confident that it is the fuel pump.

Got the fuel pump installed last night. So far so good.