wasnt this setup running ok prior to the rebuild? how are you measuring the timing? on my 2000 the crank method doesnt work, timing jumps all over the place. could you have a vacuum leak?

 

the truck ran perfect prior to the rebuild other than the rod and main bearings were wasted. i did have a vacuum leak which i traced down to the oe intake which had a small crack at the base and was slightly warped which is the reason i put the m1 intake on, i had not planned on going this far with the mods but one thing kept leading to another. i've changed and checked the cap and rotor,going to change plugs and put oe coil back on tonight and put vacuum gauge on to recheck for any leaks. thanks for replies guys, appreciate the effort.

 

you mentioned in an earlier post about retarding the cam timing, was the cam timing set the same prior to the rebuild?

You also mentioned that its running fine up till 3500 rpms then it starts falling flat on it's face... what's the fuel pressure and AFR doing?

I recommend you keep the motor as close to the configuration that it was prior to the rebuild, then work on fixing it. if the setup worked prior to the rebuild, there is no reason it cant work now.

Is the distributor setup correctly? I've never had mine out but I recall reading that there was a gear in the motor that needed to be setup right for the correct timing. I tried looking for it in the FSM and only found a reference to it. go to this thread and download the FSM and have a look for it... make sure that gear is setup correctly.

https://dodgeforum.com/m_340929/tm.htm

 

Is that M1 intake a little too much for that motor? I'm just spitballing here but if you were going to run it shouldn't you have a bigger than stock throttle body on it too? I'm just wondering if that combination is choking the motor out past 3500.

 

What is the lobe separation on your new cam? If it is less than 112 degrees you are not obtaining enough vacuum into the MAP sensor. Try re-routing your throttle body MAP sensor input from the normal location to lower in the intake manifold.This will fool your MAP sensor into thinking the reading is correct and it will stop trying to adjust your timing. I had this problem with my 01 360 as I was only getting a reading of 6 to 7 inches of vacuuma at the MAP port but 14 to 16 lower in the intake. The MAP sensor expects about 14 during normal operation.

Anyway, it only takes about 10 minutes to try this fix.

Hope it works.

 

steve00ram360,the cam timing is set at stock,when i tried to start the motor initially after the rebuild it would't start,after a little research i pulled the timing cover back off and found i had used the wrong timing marks[the mopar perf.timing set i have has 2 sets of timing marks as well as 3 keyways]so i laid the new set out on top of the oem set to make sure they went back in correctly at the stock setting, i also called the crane tech line to ensure this was correct,as for the distibutor,i'm almost 100% sure it is correct as i had downloaded a diagram of the position it should be in at tdc and it lines up pefect, i've had the front and top of this motor off so many damn times i could probably do it in the dark. silverram, not sure if that intake is too much for the stock tb, never thought about that, anyone out there have any thoughts or experience using the m1 intake with the stock throttle body? turkeyhunter,i'm not sure on that lobe sep. i think it was 112 or 114, just looked at the spec sheet that came with the cam and it dosen't list it, i'll have to give their techline another call or see if i can find it on their website, but it makes sense since the map sensor helps control the timing and i checked the vacuum at the base and not up top,guess i'll stop at the parts store after work and pick up some line and fittings. Thanks for all the responses guys i do appreciate it.

 

if your convinced the motor timing is set right (cam & ignition) then dont tear it down again. go with your instincts... if you have the skill to do what you did, you've probably done it right so leave it alone. my suggestion at this point is take it to a dyno, Look at the AFR, timing, air intake temp (if possible) and anything else they can hook into. the more data you have the easier it's going to be to fix it.

find out if it's running lean/rich or what at the 3500 rpm point where it's falling flat on it's face. although the dyno is not cheep or free, it can be your best friend at this point. tell the operator, your on a debugging mission and want all the data he can give you on it. if it takes half a dozen runs to collect it all, do it.

 

oh yeah, another thing to ask... when the fuel rail was off, did you flush it and pull the injectors off? I've heard that crap can build up in the rails and impeed flow to the injectors. popping the rail & injectors off shouldnt take too long and may be worth a look.

 

steve00ram360, i'm almost 100% certain the cam timing is right on the money,the afr gauge i installed is a summit digital led unit, it show the ratio being right on, maybe just a little rich all the way up to 3500rpm, beyond that i don't know because i always back out of the throttle as soon as the detonation starts. i did flush the fuel rails while i had them off. all my past experience with rebuild has been on carburated engines, this computer controlled stuff has me second guessing too many things. thanks for the input.

 

ok, so it's detonating past 3500 rpms... what's the fuel pressure at that point? could you be running out of volume? I had a very similar problem with my ram and I found a couple of things contributed to it... 1st being the fuel pump. my mileage started creeping up without good reason, almost made it to 15 mpg which would have been awesome if it werent for the pinging. I was also running an MSD off-road box which was killing my cap & rotor. that contributed to the pinging under load and at higher rpms. took me a while to figure it out but that was the causes...

My suggestion at this point is go get some 100 octane fuel, 3~5 gallons of it and mix it in with the gas in your tank... so your effective octane is pretty high. then take it out and collect some AFR #'s, and if you can timing #'s... maybe you just need a scan tool for the timing, IDK... but if you can see what the data is then it may help figure it out.

what coil are you running and are you running any aftermarket ignition box?