long story short. my cap, rotor, cam and crank sensor were replaced by the "mechanic". i told him ac delco everything. said he couldnt get the sensors delco but he could get cap and rotor. i go to pick it up...nothings delco. i wasnt happy. i know how these trucks run on aftermarket cap and rotor, and it only took me a week to find out. told him i wanted ac delco so i bought the delco parts online (cap rotor and cam sensor) and brought the truck back. he took out the junk and put in my parts (i think) i noticed cap was correct.

anywho. i went to start my truck after sitting overnight. it was pretty rough. checked plugs on distributor and it seemed alright. im not bringing it back to the place that did the work because i dont feel like them pulling another one over on me

any help would be greatly appreciated

 

As LeWhite mentioned in your other post, has a crank sensor relearn been performed?

 

yes i have. sorry i forgot to mention that.

 

Good job! And now someone else can chime in

 

Could be your rotor is not lined up right,double you know if he played with the distributor shaft? Sounds like the rotor is off a bit, you did say it ran but rough right? Just had fun doing this myself as my shaft had to be replaced

 

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it starts like a gem when it hasnt been sitting a while, starting to wonder if i have a small vacuum leak. it runs great since it was switched to delco cap rotor and camshaft sensor.

 

What does the misfire detection system say about your misfire? With both crank and cam sensor replaced and a fresh crank relearn it should be working great! Honestly, sound like someone has been guessing.......

But if you have no P030x codes stored or pending, but a felt misfire - then the misfire detection is not working.

I hate to keep saying this, but I really like the idea of inducing a miss to verify the misfire detection system is working properly on these problem children. It's a very easy thing to do - 3 minutes of work - but you need a scanner, an extra plug wire, and extra spark plug, and something like a pair of vice grips to clamp the spark plug against something metal on the engine. Just select a plug wire for a cylinder that is not setting a misfire code and pull it from the cap. Now plug your test wire setup into the cap to give the spark some place to go. Start the car and monitor misfire detection on all cylinders if you have the extended GM PIDs. If you don't have that capability, just look for pending misfire codes.

If the misfire detection system is not working properly, then that is indicative of a problem and diagnosing why the misfire detection system doesn't work can (but not always) lead you to the cause of an actual miss. Irregardless, the misfire detection system should be working on these vehicles.

Do you have a fuel system problem? (doesn't start well after sitting for a while?)

 

i wouldnt say theres any misfires, runs and idles pretty smoothly (smoother than recent years before this was all done). I have gone over fuel testing procedures with captain when i replaced the fuel pump (ac delco), isolating the fuel pump pressure test and at the port were both in range of what he said i needed to be at. from reading online, if there is a leak after the maf sensor and undetected air is getting in, it can cause hard starts. my issue with that is, it starts beautifully after being warmed up.

 

You could leave the fuel pressure gauge on and see if is typical pressure after the 2 sec key-on pulse (after sitting for a while). Could it be leaking and getting flooded while sitting?

If it's just a vacuum leak I know that would affect the fuel trim and O2 sensor readings. Maybe you can investigate that angle.

So it sounds like all you are really wanting to fix is a hard-start after sitting for a while? I guess I don't have anything solid to tell you past the fuel system testing. sorry.

Good luck and best wishes.

 

yea in a little im going to grab a bottle of soapy water and with the engine running, im going to spray around anywhere i suspect a leak, and see if the engine begins running rough just wanna rule it out first since it seems the easiest and cheapest solution

i do appreciate the help thank you!