Starting Issues

[UrbanOffroad215]

Recently I did some repairs concerning my intake manifold and fuel injectors. (Vortec 5.7 SFI) After my repairs the motor ran great for about a week. Around day 5 it started giving me some trouble starting..It would take about 2-3 cranks to turn over..then a few days later it turned into 4-6 cranks. Now it just cranks and does nothing. Not even a sputter. If i spray a little starting fluid in the intake, it fires right up with no hesitation on the first crank and runs smoothly. Once started, It runs and drives fine under normal driving conditions. If i put the peddle to the floor, It struggles like it is starving for fuel and wont go above 3000 RPMs. I replaced all of the seals and gaskets on my injectors and manifold, Installed a new air filter and fuel filter. All connections are connected and secure. Checked my fuel pump and it is working properly.

I am completely puzzled by this. Does anyone have any ideas?

 

[barebones 1500]

i would check spark. maybe it is starting to get weak and it is not enough to pop on start-up or heavy load. also does your starter seem to be cranking good? i haven't seen it too much but i have seen some that can't get the motor to the right speed for starting but are not bad. if both those are good then it might be a sensor or something, not sure which one it would be though. hope that something in there helps or someone has some better info and you get it going.

 

[UrbanOffroad215]

i would check spark. maybe it is starting to get weak and it is not enough to pop on start-up or heavy load. also does your starter seem to be cranking good? i haven't seen it too much but i have seen some that can't get the motor to the right speed for starting but are not bad. if both those are good then it might be a sensor or something, not sure which one it would be though. hope that something in there helps or someone has some better info and you get it going.

My starter seems to be fine. Spark as well. I pulled all the plugs and wires, everything seems to be working correctly. I thought a possibility could be timing. But i do not have a scanner to check. Apparently timing can not be check with a timing gun on the Vortec motor. A stupid design in my opinion.

 

[barebones 1500]

if spark and starter check out then your guess it as good as mine. i had an explorer with the same problem but it would barely pop with starting fluid. put it in the shop and they went through EVERYTHING and still could not find a problem. try hooking a scanner to it and checking for codes that might point you in a better direction

 

[Hodges87]

What is your fuel pressure with the "key on engine off" & "key on engine running"? It sounds like a fuel delivery problem (fuel pump or fuel pressure regulator)

 

[UrbanOffroad215]

What is your fuel pressure with the "key on engine off" & "key on engine running"? It sounds like a fuel delivery problem (fuel pump or fuel pressure regulator)

I dont have a fuel pressure gauge to check.. After speaking with a GM tech today..he told me that a good possibility is that my EGR may be clogged with carbon "pellets" or pieces of carbon. Apparently this is a common issue when doing any repairs that involve the "spider" injectors.. I am hoping this is the case, id really hate to take my manifold apart again