Occasional starting problems (fuel pump?) Please Help!

[frito-bandito]

I have a intermittent starting problem on my 98 ECSB 5.0L 4L60E. It started about a week ago, I noticed that sometimes, the engine had to crank a little longer than usual to start. Then it would start normal for a while. We took the truck cross country to Minnesota last weekend with minimal problems, it only took a long time to crank maybe two times. Yesterday I went to my friends house (about 10 miles) and when I went back out to leave an hour later, it would not start. So I sprayed some ether on the air filter and it started but died once it burned off, so obviously its a fuel problem. I left the truck there overnight and when I went to tow it home this morning, it cranked right up. So far I changed the fuel filter, and it still is hard to start sometimes... would a fuel pump give me intermittent problems like this, or is it something else? Thanks.

*edit- I forgot to mention that once I get it running, it runs perfect, thanks again

 

[Hodges87]

Yeah a fuel pump would cause this problem. You need to buy or borrow a fuel pressure gauge and test your fuel pressure. It should be 55 or over while the engine is running, and 55+ with the key-on engine-off (55 minimum, 60+ ideal)

Also a fuel pressure regulator will cause this problem. Do a search and I'm sure you will find some good info on it.

 

[frito-bandito]

Thanks, I suspected the fuel pressure sensor, the only thing I'm not sure of is how the truck wouldn't stay running when I sprayed ether in the intake. is there anyway to test the fuel pressure regulator other than a fuel pressure gauge. (I know on gmt800s you pull the vac line and if there's fuel in it, the sensor is bad, but I don't think this is set up the same) thanks again for your help!!

 

[EMT96]

Turn your key to the on position and listen for a humming sound . That sound would be your fuel pump. If you don't hear it the pump isnt turning on.

 

[frito-bandito]

I did that, I can't hear the humming and the truck suddenly is working fine