• The site migration is complete! Hopefully everything transferred properly from the multiple decades old software we were using before. If you notice any issues please let me know, thanks! Also, I'm still working on things like chatbox, etc so hopefully those will be working in the next week or two.

misfires after cam install

G

gtptim

New member
Well I just install an XP cam. When I started the car up and leave it idle the RPMs will jump up all of a sudden and back down then it will idle. It do this repeatedly. I have checked for vacuum leaks repeatedly and found nothing. I even took the supercharger back of and siliconed the gasket and it will still do it. I did a compression test and every cylinder is within +/-10 of 160psi. Someone else said I should be using 103s instead of the 104s. The plugs are lapped .060 and I'm using PRJ wires. My current mods is Gen5, 3.4mps, XP cam, TOGs with cat-less down pipe, custom ported head with matching ported LIM, 180* drilled thermostat, and 42.5lb injectors. I'm at a lost to what causing this but I am see some mist coming from my exhaust but I don't know if that's normal for a cat-less exhaust system or not?
 


you double check the plug wires are on right?


plugwires.jpg
 
Plug in a code reader and tell us the codes if you have any. Are you getting misfires and if so on what cylinders.

Is the only thing you changed the cam, you already had the gen 5 and other mods on the car and running.
 
Rico said:
A 3.4 with a GEN V? Holy crap Batman!
Click to expand...

I should be able to run a 3.2 or push it a little bit and run a 3.0 pulley but the biggest pulley that I had at the time was a 3.4 pulley. I know I got the plug wires on each cylinder rite but on each ignition coil Idk I will have to look when I get back into town. I have an aeroforce gauge but its saying I have 0 misfires but I can go to the back of my car and hear it misfire out the end of my exhaust.
 


gtptim said:
I should be able to run a 3.2 or push it a little bit and run a 3.0 pulley but the biggest pulley that I had at the time was a 3.4 pulley. I know I got the plug wires on each cylinder rite but on each ignition coil Idk I will have to look when I get back into town. I have an aeroforce gauge but its saying I have 0 misfires but I can go to the back of my car and hear it misfire out the end of my exhaust.
Click to expand...


I'd stick with the 3.4. Headers and cam don't equal 3.0 in gen 5.

Your getting no codes?
 
at idle, too small of a gap will cause misfires... And that being said IDK how mine even runs it misfires at idle so bad.

as far as the idle surging... many things cause that, usually its tuning related and considering you changed like everything... uhh.
 
sseilmnop said:
I'd stick with the 3.4. Headers and cam don't equal 3.0 in gen 5.

Your getting no codes?
Click to expand...

How do you figure that? I dont read no mention of ported heads in the quote from you. I do have 2 codes coming up on my aeroforce gauge but there from my EGR valve which I deleted the EGR just didnt delete them from the PCM. Yes the plug wires on everything is correct.
 
Last edited:


gtptim said:
How do you figure that? I dont read no mention of ported heads in the quote from you. I do have 2 codes coming up on my aeroforce gauge but there from my EGR valve which I deleted the EGR just didnt delete them from the PCM. Yes the plug wires on everything is correct.
Click to expand...

Not sure how to gauge custom ported heads. If you can run 3.0 with no knock great. I think you will end up bigger.
 


Rico said:
A 3.4 with a GEN V? Holy crap Batman!
Click to expand...

3.5 runs pretty good too ;)

Gen V can be fun, clayton is running a 3.4 on his gen V with an s1x cam and derek with his vs. Gonna advance my timing and retune to see what I can pull with the 3.5 and then drop it down to a 3.4 and retune depending on my injectors.
 
You must log in or register to reply here.
Back
Top