I have a 2001 4x4 that had a gutless 318. Did the usual mods to get some power. No dice.Decided to buy a 360 long block from Carolina Machine Engines.Swapped engines and now I have a mis/studder that drifts in and out at idle and just above.Not a dead constant mis.Truck has good power when you stomp on it.
Mods include- Thumper throttle body,Mopar Performance intake, Ford injectors, ordered long block with " RV " cam , SCT tuner from Hemifever with cam-heads tune.
Changed harmonic balancer and flex plate to externally balance 360.
Distributor is in correctly. Fuel sync'd with a borrowed Snap on Solis.All ignition components are brand new except cam sensor. I have swapped ignition system around with old parts from 318 to try to diagnose. Nothing changes.
What do you guys think I should look at. I'm at a complete loss.
Like I said before truck has power just has an irritating mis that comes in and out at idle.

 

Did the tuner compensate for the motor change from a 318 to a 360? I am not sure but wouldn't you need another pcm?

 

nah- no new PCM.. that one can be modded to handle it..

what the 360 has in displacement, the 318 has in greater lift and duration- it's damn near a push (so far as lean/rich are concerned)..

my concern would be matching up the cam to the injectors and ignition timing.. it may be that you'll need to locate a performance shop and have it dyno'd to be certain.. when you mess with a cam you mess with valve timing.. when you mess with valve events you mess with proper time to squirt..

you could call hemifever and ask about the cam set up.. if you have the card or the grind, it's possible he already has a tune for it..

when your engine was built, did they put the chain on straight up or advanced/retard it? that could be an issue, too.. It may be as simple as calling and asking them how the timing chain was installed.. if it's cammed, it may likely be mechanically advanced there- which will cause issues especially at idle if you don't know about it..

put that borrowed scan tool back on there and look at raw data.. monitor vacuum signals and timing advances.. check out your fuel trim too..

you'll get there eventually, dude.. new engines and/or cams take patience to get right if it is a road less traveled..

 

I havent called Carolina about the cam but I doubt its that big. I was hoping the cam tune would have fixed it.
I have a tech buddy I'm thinking of dropping the truck off too thats an ace with his scan tool and just pay him. I'm about at the end of my rope with it. Hoping somebody that has done this swap might have seen this before and had a fix.
In the mean time I will contact Carolina on the cam.

I will say the truck runs and drives like a truck now with the 360. It was an 100% embarrassment on 33's with the 318 trying to pass somebody or pull a boat.

 

have you contacted Hemi? if its running good everywhere except at idle, i'd guess the tune is just slightly off. describe it to Hemi and make sure he has the cam spec's. try some different tunes by trial and error.

 

well let's say it isn't a big grind w/ huge lift.. let's say it increases duration on both phases of valve actuation.. let's say it opens about 5* sooner than the OE cam, which would be about right for an RV low end torque cam- if so, if your fuel sync is dead nuts 0*, that can cause issues.. you'll need to advance the fuel sync to match the valve events...

let's keep figuring here.. and though I figure your issues are about ignition and fuel timing, let's reach further out.. idle.. what cam grind did you use again? where does it produce peak? what torque converter are you using? what is your vacuum signal at idle, in gear with your foot on the brake? if you are producing enough torque low enough, you may have created a mismatch that will have to be addressed.. I doubt it, but it's a possibility..

which FMS injectors did you select? If they are in the 225ml/min range, (19~21#), and you increased your lift and duration, you may be starving the engine at idle.. if you used larger, say 252ml/min (24#), you may be too rich at idle.. you'll have to wideband it and get a good look at your a/f ratio..

generally speaking, and for what it's worth-

OE injectors stream more than spray, and fuel sync @ 0* catches the valve train a hair before opening- what happens is the spray atomizes off the back of a hot valve so it's better dispersed.. if you use four hole sprayers like most FMS injectors are, you are better served retarding the fuel sync.. mine likes -3* w/ the 1.7rr's, but yours will be different.. it means it doesn't hit that valve so much as it directly injects into a gasping cylinder.. poof- better response to power- but also, less duty cycle of the injector because the volume of a 24# injector at 50% dc is equal to the volume of a 21# injector at around 70~75%.. better use of the fuel sprayed takes place.. this HAS to be tuned into the PCM tables, and the Fuel Sync HAS to be done with a scan tool.. it's a very nice mod when done correctly..

we (you) gotta know about that cam.. you gotta look at the map of it, or you gotta dyno the thing and let a pro do it.. HemiFever most likely will know precisely what needs to happen, as he has nifty software that crunches the figures (ratio, length of rods, lift, duration, event timing, best time and volume to spray, ect..) he WON'T be able to help you with fuel sync.. you'll have to discover that on your own with your buddies scan tool..

you may be aggravated, and I can appreciate that for sure, but you're likely not that far away from having one bad **** rig.. see it through.. break it down into small edible portions and make sure those are right before moving to the next portion.. you'll get there..

I'd call crane cams.. or, I'd consider logging into bionic dodge and asking Marty about cams and grinds.. HemiFever hangs out there more than here.. you're a little beyond 'help I'm broken' which this place is fantastic for, you're more in the realm of 'I gotta tune and balance my performance parts and pieces', which that site is better for..

hang in there..

 

Did you have fuel sync reset?

Did the crank sensor get bumped when installing the engine?

Did you have the PCM reprogrammed for the larger engine?

Real possibility what you are experiencing is a Lean-Burn Miss. if the pcm thinks it's idling a 318...... I do believe at idle, it is in open loop. (ignoring the O2 sensor) So, mixture may not be quite right.

 

also, at idle, the timing lowers to single digits and the fuel sync bounces quite a bit..

I'd be curious about the timing chain- I wonder if the builder advanced timing there, which will toss the PCM's thinking and cause an advance at idle it doesn't want..

 

I gave sean the specs on the cam and he said the cam could be run with stock programming but it would not be optimal.
I keep hearing about reflashing the PCM to the 360....isnt that what a custom tune is for or am I missing something? I wish I could get a definite answer on the PCM flash.And who do I get to do it?
Bottom line is the "RV" cam is not big enough to cause this issue . But it was there in the beginning as soon as the new engine was started.Sync'n the fuel never changed anything.
Getting it scanned is my next step I guess.
There is nothing left to change but O2 sensors. I'm tired of throwing money at it with no results.

 

Try running it with the O2 sensors just disconnected, see if it runs any better. if it doesn't, don't bother spending money on them.

If you PCM has been reflashed..... my question would become: Who flashed it, and what did they flash it to?