Misfire on new motor

[Phone Man]

Yes. Get the motor to TDC on the #1 cylinder as explained. Drop the dist down making sure the rotor points at the #1 tower. Most caps have the cylinder numbers on them.

 

[pontiacgta2002]

Okay, i have 3 videos i took and placed on youtube. Dont mind the file name as i didnt change it before uploading them. on the 3rd video showing the scanner i cant get it any closer to 0 can_retard as it is hitting the fuel rail and upper intake. I hope the below links work for everyone.

1. http://www.youtube.com/watch?v=8T36eJaIECg
2. http://www.youtube.com/watch?v=ircE6wnER1Q
3. http://www.youtube.com/watch?v=CA_ecH6ywUo

 

[Phone Man]

Your misfires are all at close to zero. Having a few is normal. Get the timing to 0. On another note, the position of your dist is a bit off in comparison to mine. The flat face of the front of the cap runs parallel to the edge of the intake on mine. It looks like the #1 wire is pressing against the manifold. It just seems wrong to me. If you turn the dist counter-clockwise you'll get to 0?

 

[pontiacgta2002]

If i turn the distributor counter clockwise it stumbles and goes up into the 35+ range on the cam retard. if i turn counter clockwise it wont start and while running it starts to die. If i move the distributor counter clockwise one tooth i can get to read 0 cam-retard and into the negative numbers with no advance for cam_retard. I also find that it stumbles when starting it up after it has been run. once it catches up to its self its fine. Has any one ever had to adjust the valves on one of these new motors? Sounds like the rockers on number 4 cyl. are loose.

 

[07whitetahoe]

Is this dis. new? If used, is the gear worn? A worn gear will be obvious and is cheap to replace. Cam retard -+2* is acceptable. When you get a reading on scanner, it is set in pcm. You have to rev the engine over 1100 RPM to get a new reading when adjusting for cam retard.

As previously mentioned, if you are a tooth off you should be able to rotate it close enough, unless the gear is badly worn.

Rockers should be close. I've had them make some noise, but even if they are loose they won't cause a misfire. BTW they are self aligning rockers.

 

[SunlitComet]

your rotor is off one tooth towards clockwise. that is to much rotation on the cap. as far as your misfires go i think you should fix the install first. set the retard to zero as measured at specified rpm's redo your crank learn and recheck to see which one misfires afterwards. we will address your rocker arms afterwards.

 

[pontiacgta2002]

Okay got it set to 0 by moving the distributor counter clockwise one tooth. She sits at dead 0 cam_retard. CPK learn has been re-learned. Seems misfires on 1, 2 and 3 cyl now. So people say that a few are okay, why is that? I will do a video of the noise i hear under load this evening and hopefully the camera will pick it up.

 

[SunlitComet]

on run your monitors like before would like to see the history on video again.

 

[pontiacgta2002]

Okay, here are my latest videos please feel free to comment.

http://www.youtube.com/watch?v=KNQERUXmBK0&feature=g-upl
http://www.youtube.com/watch?v=ao6UtoBHPDM&feature=g-upl
http://www.youtube.com/watch?v=_BA496Lwn4w&feature=channel&list=UL

 

[SunlitComet]

so far so god . and excellent work on the dizzy position and cam retard. was the cap an rotor from delco or someone else? also did you ever update to the new injector system? other then a very unlikely compression problem the only other thing that comes to mind is sticky valve to valve guide issues. but that happens under load. more details on make and # of cap, rotor, wires and plugs please. i think your sparks are bleeding out some where. that is what i read from your scanner results.

 

[pontiacgta2002]

THe new distributor is a no name brand. I did update to the MFI system, the motor is brand new GMgoodwrench crate motor. Plugs im using are ACDelco iridium, the wires I think are Duralast, i discarded the box. My old cap has white deposits all over the posts and the rotor has black soot on the tip of it. I see this on the new distributor also. I'm going to try and post the pics of the old distributor cap and rotor.

 

[pontiacgta2002]

Cap and rotor pics from old distributor. New one starting to look like these also. Plug gap is .060

 

[noJeepshere]

Get some ACDelco parts to replace that cap and rotor, they're a known weak spot in these motors. Even that little bit of corrosion will cause a few misses. Make sure that whatever you but, it has brass internals, not aluminum ones like yours has.

 

[SunlitComet]

white and crusty is normal over time but i hope dark line below rotor tip is dirt smudge. if it is carbon tracking then you are screwed. for now the duralast wires should work but get delcos when you can. for the cap and rotor replace it now with delco units. D465 rotor and D329A cap. $40 at amazon plus tax & shipping if that applies to you. I pay neither. oh and 9718Q for delco wires when you get to it. unless you want beefed up wires. the plugs are delco 41-993?

 

[pontiacgta2002]

Here is what i have as of now. I replaced the cap and rotor with ACDelco ones. Im still getting the misfires over a few different cylinders. I have attached some pics from the scanner showing the misfire results. The plugs are ACDelco 41-993. Would or could the Electronic Spark Controller (ESC)cause these misfires? The ESC and the computer (PCM) are the only direct ignition pieces that havent been replaced. The MAF, MAP and EGR sensors all test okay. Side note the truck use to start on the first key turn hot or cold with in 2 - 3 seconds old motor. Now every once in a while i have to turn the key two or three times before it starts and sometimes it will stumble then catch up to its self new motor.

 

[SunlitComet]

i cant recall have you compression tested the engine or know the condition of intake gaskets?

 

[pontiacgta2002]

The engine is new so I never did a compression test. Guess i could to rule out any issues with it. The intake doesnt appear to have any leaks. I have sprayed carb cleaner around the intake mateing surface and everything seem tight.

 

[Matt06Yukon]

Are you getting any codes? From what I can remember from my Dizzy install, its been a couple of years, was I had to get it fairly close as far as lining up with #1 TDC and then the PCM would take over ? I did have to play with it for awhile, and it did seem like it wasn't perfect, but the codes went away and it runs awesome. Don't know if it adjusted the little bit that it had to or I got it right on. My Dizzy was off ebay for like $55, all aluminum and definitely cap and rotor with brass points. I've never had an issue since I last worked on it. New intake gaskets, new dizzy, new spider assembly, and new water pump. Starts on about a half a crank everytime, be patient you'll get it.

 

[SunlitComet]

no don't bother with the comp test. as far as the intake i was more concerned that coolant was the stuff leaking in but now that i have looked at your misfires screens again i know that is near impossible. How about watching your valve train while running looking for sticking valves?

 

[pontiacgta2002]

I'll pull the covers off not this weekend but the following one and shoot a video of it. I'm getting a noise on the driver side, ticking sound. How much oil should i see flying around in the valve cover when looking in through the oil fill hole?