Help me fix the hard start in my 98 I just sold

[ChrisAU]

So I thought I had it fixed after it fired right up 4-5 times after replacing the fuel filter like it was a brand new truck. However, today my buddy told me its doing the same thing it was before that. I don't think its the check valve in the fuel pump, you can cycle the key all you want and the starting symptoms are the same. The pump will buzz the first time you turn the key, but on successive KOKO's, it is silent. The truck will start after about 10-15 seconds of cranking and run fine. No codes other than one for the oxygen sensors, which is due to it not having cats. Where should I start? I am suspecting injector/regulator issues, the truck has 288k on it. Whats the best way to diagnose that?

 

[Birchyboy]

Whats the best way to diagnose that?

Have your friend take it to a garage

 

[badazzbulldog]

crack open the throttle body and shine a light in and see if it looks wet in the plenum

 

[ChrisAU]

Thank you sir, we will do that tomorrow. He is coming over and we are taking my winch off and putting new plugs/wires in it. It does have a slight miss under load, maybe that will fix it, and it needs it regardless.

Reading up on FSC it may be the fuel pump. They are saying anything less than 60-65 PSI and it will struggle to start but run fine on 50 PSI or more.

 

[badazzbulldog]

a clogged return line to the tank can cause hard starting also.went thru this last winter blew out three pressure regulators before issue with return line was found

 

[ChrisAU]

How did you fix that?

 

[kennythewelder]

Vortec engines are very sinsitive to fuel pressure. If the fuel pump is not putting out over 60 psi, you will have trouble starting the truck. Once the truck is started, it will run fine, and even start good as long as it doesn't sit for a long time, (like ever night) When I had this issue with my 97 Silverado 5.7 L. After trying everything else with out any of it helping, I ran a fuel pressure test. My pressure was in the 50s. I changed the pump, and it is now around 64 P.S.I. The truck now starts as soon as you turn the key, like it did a long time ago. There are some good how to test you fuel pressure videos on you tube.

 

[badazzbulldog]

ran new steel line from tank to the section under the cab where it changes to rubber line before it goes up to the engine.undid that connection and tried to blow air back to tank thats how i found the blockage.it was rust in the line

 

[ChrisAU]

We are supposed to work on it this coming weekend, doing plugs and wires and then some diagnosis if it persists. Wondering if the CTS on the manifold may be a possible culprit?

 

[bluex]

Check the cap an rotor to. Mine was throwing a code for the ignition module an turned out the rotor was shot an the cap had all kind of crud on the posts