2000 k2500 454 starts sum times right away and sumtimes it cranks like it dose not have spark.

[braedan mlodik]

Sum times the truck fiers right up. Other times it cranks for like 20 seconds and then it starts but dose not reve up to a normal runing rpm. I did new lower intake gaskets and had the injectors rebulit. Put a new fuel presure regulator in. Got a new distributer cap and plug wires. New fuel pump, New plugs, new fuel filter, New iac, New pcv. It just seams to start bad sumtimes and sumtimes it fiers right up. When the truck is runing it runs great and has all the power you need. Thankyou you in advanced

 

[Schurkey]

Connect a scan tool, find out what the computer wants you to know. "Codes" can be helpful, but the real diagnostic power is in the data stream. I'd be looking especially for an RPM signal when cranking, Coolant Temp Sensor accuracy, and TPS accuracy.

Confirm proper fuel pressure, and proper fuel pump "prime" cycle when key is turned from "Off" to "Run".

Assure no vacuum leaks.

Test coil spark-power using a spark-tester calibrated for HEI.

 

[someotherguy]

All of what Schurkey said, and to add to it I'd question rebuilt injectors. Who did them and did they give specific details on what was done? It's my understanding there's no rebuilding the Multec injectors that are original on these engines. Someone may have just flushed them with cleaning solvent, replaced o-rings and called them good, when the OEM injectors are a known trouble spot on these engines.

Richard

 

[braedan mlodik]

The injection were not rebult they were tested and all new o rings put on. It was done by my local injection place and they do great work we take all of our diesel injection stuf there and never had a prolbem. Thanks for all the help and I will try hooking a scan tool up to see what it seas.

 

[someotherguy]

The original Multec injectors are terrible and are often the cause of a long crank/stumble to idle symptom on the Vortec 7.4. The FPR is another suspect but I see you've already replaced it. I wouldn't rule out the injectors, as they tend to leak. However, I wouldn't just shotgun them as they are expensive $$$ and you already put money into the ones you have. I'd go through Schurkey's suggestions and also be sure when it acts like it doesn't have spark - does it have spark?

Richard

 

[braedan mlodik]

I tested it it dose have spark. I ordered a new crankshaft position sensor to see if that will fix it. If that dose not do it I will have to throw it on a scanner to see the rpm signal and coolant temp sensor activity. And I also put a new tps in so I hope that is not the prolbem but you never know.