i have a 55 chevy i did a 53 swap in, all was great been driving for 8 years i guess maybe more , this is second time , the first time my car wouldnt start i pulled my hair out trouble shooting and finely changed battery and started right up, this time i drove to town to car meet and drove home washed and cleaned it and must have left the door ajar or something it cranks fine but i only here the fuel pump for a sec, normally i here it longer, i got a new battery and same thing.
so my question is why ? its cranks fine ( fast ) but no fuel pump or hit
the first time i checked the fuel pressure and 2 relays found nothing all i did was charge the battery, this time must be something different . iam going under and check all my grounds .
what else can i check ?

 

motor needs: fuel, spark, compression

battery is good as you say. I would test starter and alternator. easy to check.

After that I would check fuel pressure. Also check for spark at the plugs.

 

i did all these things the last time it did this, the common thing i notice the fuel pump only runs for a sec at most, it normally runs longer 5 or 5 sec ? ill check pressure at fuel rail and see what i have to start with, if i have 58 or so after it shuts off ill go on to something else
thanks

 

it cranks good , i swapped the relays and no good , ill check fuel pressure at rail and check spark .
where can i get a diagram for wiring ?

 

For what? The 55 Chevy, the unknown year or vehicle 5.3, or the possible aftermarket harness.

 

Maybe you should pull the codes, that may be a great starting point, and where I would start.

 

yea 55 chevy i did a 5.3 from a 06 truck

 

no codes that my problem , i dont remember the name of after market harness

 

might be a good time to invest a good obd2 scanner. would recommend a Xtool D7. it's basically a small computer. will tell you everything you need to know.

 

i went out this morning and plugged in both relays and checked to see and it started the fuel pump ran like it should the 3 to 5 sec. so now i have to wounder did i have a stuck relay ? and if so why , its been like 8 to 10 years on the build, the brand is hella should be a good, so anyway i will start carrying a extra relay in glove box

 

I went out this morning and plugged in relays and turned the key on and heard the fuel pump for the long term and started right up, could I have had a bad relay or stuck relay ? is there a better relay to get ?

 

is there nay relays better than others? mine is a hella brand