5.9 magnum hates mods?

http://www.bionicdodge.com/Download/Adjusting%20the%20idle%20for%20a%20Magnum.pdf

http://www.bionicdodge.com/Download/Camshaft%20Timing%20and%20Setting%20Fuel%20Sync.pdf

From my site, maybe these will help.

Man, you guys are awesome! All good advice and I'm reading the PDF's from Bionic Dodge now, good stuff. I thought the Mopar Performance computer would be able to keep up with these mods, & if it was a '96 I would be able to flash it. I will get this thing synced this evening, and see what it does. What would be the next step up for injectors? I think I recall reading something about using blue ford injectors, but I cannot find it. Thanks again for all of the replies.

Tom in Texas

No problem. Bruce is a Ford guy but his site is a good source for injectors.

http://www.fiveomotorsport.com/

Well we think we have solved the rough idle problem. For several days I had a friend over tearing down the motor when we started this build. Well today we noticed a lot of jitter in the timing & misfires, so we went back to check the crank sensor and reluctor, and every hole was bent up so badly that it chewed the end of the sensor off.


With friends like that, who needs....

Remember, MT and AT crank Hall effect sensors are different lengths. Or...crank bolts loose?

Rick

looks like a bar in the cps slots to rotate the ingine during build up ??
Thad

Yep, large phillips screwdriver was used to turn the crank. Truck now has a new reluctor and sensor, but still isnt running right. Any Magnum experts in the Houston Galveston area??

Ps: The cam barely made the engine lope, no interference with the pistons, good vacuum. Yay! I cannot run the Mopar perfomance computer at all though, it makes the engine run really rich, my eyes were burning like fire until I switched back to the stock box.

Just a quick update & some dyno data. Pig rich condition was caused by a TRW o2 sensor, switched to NGK & truck ran good. Still not the power I expected from the mods though, so I put it on a dyno in Houston & here are the results.

RPM. HP. TQ. AF.
2250. 89. 209. 12.6
2400. 93. 202. 11.9
2700. 105. 205. 11.7
3000. 114. 200. 11.3
3275. 118. 190. 10.9
3575. 125. 180. 10.3
3875. 129. 175. 10.3
4175. 134. 167. 10.2
4450. 135. 160. 10.2
4750. 152. 169. 10.5
5000. 160. 169. 10.7

Obviously something is killing it in the middle, good TQ off the line, flat on her face until 4700 when the AF starts coming back up. From top to bottom I have a 5.9 mag, 14" open air cleaner, stock TB, stock injectors, Mopar M1, Comp Cams 262hr, MP lifters, EQ Magnum heads 2.02/1.62 (no port work), MP computer, large exhaust manifolds dumping into 3" magnaflow cat, then to a 3" muffler that splits to 2 tailpipes. Is the stock TB choking her down? This has me stumped, and wanting to get a megasquirt II & wideband so I can tune it, obviously the Mopar box can't cut it...

have you pulled the distributor? If so who set your fuel sync and what is it set at? It could be your fuel sync is so far off that it is running rich.
Just a thought. Mine is set around 0 to +1, the computers will run as long as its set anywheres from -10 to 10.

I stabbed it per the instructions on bionic Dodge. I did call 3 local dealerships to get it synchronized, but all 3 said they didn't have the box to do it anymore. I'll go back & do it again tomorrow just to be sure. Do you really think the sync would hurt it that much? Thanks for your suggestion, I'm stumped...

The stock computer goes to max injector pulse width above a certain RPM and with the throttle floored, so the AFR change as RPMs increase is normal. Not good for fuel economy or power, but safe.

the fuel sync tells the injectors when to fire. The dealer ship needs a DRB to be able to set the fuel sync. It literally takes about 5 minutes to set. There is one snap on unit that can do it too but I do not remember the number for it.

I think that wild cam is causing all the problems.

Your dyno numbers are really low, it's almost as though this thing has no compression. Perhaps the cam is bleeding what little compression (8.9:1) the 360 has out of it?

There is a Mopar cam that is supposed to match the PCM you have, that may be another route worth looking at.

Not sure if you have come across this yet, but there is a re-flash available from Chrysler that will raise the shift rpm and make the truck feel a bit more responsive. I had it done to my '01 360 but it has the stock PCM. Just my opinion, but I would go to a 318 Magnum cam (hotter than the 360 cam) and go back to the stock PCM.

If you have to stick with what you have, you could also go with a four-barrel.

What is the measured intake centerline on the cam? What's the cranking compression? Which ECU are you using? That's way too rich and hurting power. Can you measure the vacuum at WOT to see if you've got an intake restriction? How about exhaust back pressure?

Seriously, do yourself a favor. Go to a boneyard and pull a OBD2 pcm from a 96 Dakota V8 truck, pull the computer harness and OBD2 under dash port. Get it wired, its not that hard. Then, call Marty at KRC performance and have him build you a tune that you can download through a SCT tuner. You can run that cam with your combo, but I agree that it is probably to aggressive for that compression ratio, injector size and throttle body. A SCT tuner is dirt cheap right now and the parts cant run much more than $100.

KRC Performance no longer exists. I would double check the cam is installed correctly. Sounds like cam timing is off a tooth. Also, are those cam duration numbers at .050" lift? If so, thats way to big for the PCM. If thats advertised, that cam is fine.

I got mad after the 5th dealership told me they couldn't set the sync, & bought a Snap On MT2500 scanner. Sync was off, +12 so I rolled it back to +6 per the recommendations of some Ram & Jeep guys. Other numbers from the scanner were:
Idle 736rpm
Map 2.1v
Tps .82v
Closed loop
Vac 15.2v
IAT 2.87v
Coolant 2.0v
O2s .1-.6v
Adv +6deg
Sync +6deg

The can is really tame, duration @ .050 is 206/210, 112deg Sep, 108 centerline. One interesting thing I found, is the scanner will not talk to the MP computer, only the stock computer. It does feel stronger now that the sync is rolled back, but still not what I expected from these mods.

Now that you tried what the internet hacks said, try what the factory says and set it at zero

That's the plan. When I can find another $25 dyno weekend in Houston, I will do some pulls at 0, 3, & 6 just so we can see once & for all what the magnum likes.

Something else is still wrong, that combo should run it's ass off in a '95 even with the synch a few degrees off.

I would to +4 for that combo.

Re-check the cam timing

Check the compression on all 8 cylinders. You may have a problem there, too.

Are you sure that the valve train is right? Is there a valve hanging open due to wrong pushrod length?

I ran a lot more cam and head combo in a 318 on nitrous with the stock 19lb/hr injectors. That stuff is not causing your problem.

Good point Ron. What rockers and pushrods are on this thing? Does it still have a catalytic convertor that might possibly be plugged up?

Cat & entire exhaust is new, all magnaflow. Used the comp cams double roller chain, used the 0deg marks, but will see if I can scrounge up a degree wheel. Heads were ready to run from Clearwater, had beehive springs, comp cams tech said spring pressures were close enough to recommended, so I torqued them down. I'll run a leakdown when I do the compression test, just to be sure. When I get the new TB, I figured I would be just under 300 to the wheels, this thing should be well over 250 now...

Here's a fairly easy and quick way of telling if the cam timing is off without pulling the front cover, using degree wheels, or a dial indicator. It works for me to at least tell me I'm close. IIRC the cam gear has 36 teeth, crank 18. 2:1 ration. Every tooth on the cam gear is 10 degrees of timing. Put the engine at TDC #1 intake (not compression) stroke. The balancer on Mag motors has 4 slots around it every 90 degrees. Get a tape measure or better a tapestry tape and measure from the #1 mark to the next mark counter clockwise. Cut the measurement in 1/4's and mark the balancer. Each mark is 22.5 degrees. Get your cam card, see when intake opening starts. Pull the #1 intake rocker and as you turn the crank slowly clockwise, watch the pushrod. As soon as it moves stop and see where the balancer lines up on the timing cover. The cover has ten degrees of timing marks, so you should be able to figure out if the cam is any wheres near close to opening like the card says. This worked for me when I found my timing set off 3 teeth. I did the math, figured out how many teeth to turn the cam gear and the engine fired right up. It's not accurate to a single degree, but if your off one tooth, it will tell you.

Many years ago I had a timing set that was several teeth off.

I'm also thinking valve timing is off.

"Fuel sync" does very, very little (emissions mainly, and a skosh of low-end torque) - BUT, if way off, the distributor rotor can be misaligned with the cap towers - that's why is needs to be set right. Many early MPI systems weren't even sequential - they were batch fired.

Rick

What does the truck sound like? I put a cam and timing chain in a 81 dodge truck I had (MP260/268) with a 318 and lined up the wrong dots (MP chain, it appears that one set of dots may have been for a set up for a machining operation possibly, but there was definitely 2 dets of dots, on opposite sides of the gears IIRC). The truck ran but sounded REALLY weird. It had dual exhaust with glass packs and was very loud with the cam set up wrong, it would REALLY bark at low rpms (1500), then completely run out of steam at about 3500 RPM and sound almost like a high revving deisel, very weird, and it had about half the power it should've. It also ran hot. IIRC the chain was out about 3-4 teeth advanced.

http://www.youtube.com/user/tommyjdj

Here is a video of the truck running.

That engine is running how it should be running on the low end with that combo. (Based on what I'm hearing in that video, but you didn't crack open the throttle there!)

Your biggest problem is that it's not tuned, and you don't know for sure if the cam is timed properly right now.

Just a final post about this project. I installed a polished TB from a board member, and it helped a little, but I never was able to get this truck right. My guess is the cam was a little off, and I sold the truck to help pay for new toys. If anyone else does a Dak, may I suggest a couple things? First, start with a 96 or newer truck so you can tune the thing, or get the other M1 intake and put a carb on it. Second, double and triple check the cam timing! Save yourself the headache, and buy or borrow a degree wheel. This truck should have been well into the 13's at the track, not 17's. I'm now working on a 71 Demon 340, and have bought a degree wheel, do not trust the marks.

Tom