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Re: 1996 dodge van, 5.2 mag. what controls the fuel & timing? [Re: 360view] #2403711
11/14/17 09:39 PM
11/14/17 09:39 PM
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Balt. Md
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383man Offline
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Originally Posted By 360view
1996 first year of OBD-II software in PCM.

PCM fires ignition coil after getting signal from slots in flexplate rim, then calculating delay. PCM "knows" number one cylinder from sensor in distribultor.

Fuel injectors squirt individually for each cylinder, but spray onto backsides of closed intake valve for better atomization.
Below 80% throttle, PCM "knows" air to fuel from O2 sensor and keeps modifying two memory counters, one short term and one long term AFF and AAF, to stay near 14.7 to 1

Above 80% throttle PCM goes to very rich air to fuel ( 10.5 to 11) to surpress detonation and to keep catalytic converter ceramic from melting/ cracking.

Several "off road" PCM OBD-II software modifiers can write a custom tune.

Your friends 1996 still has mostly individual wired up speedo and gauges,
but the OBD-II PCM had its first year of twiddling with the pressures inside the automatic 46RE trans. Also first year of EGR valve elimination.

http://dodgeram.info/tsb/1996-index.htm

Has list of known engine trans issues.
Be sure to re-route the ignition wires.
Check for blown plenum gasket.



Very well said. From my years at Mopar dealers I would have said just about the same as you did a good job explaining it. Basically he is saying the dist hall effect is the cam sensor on your eng as it has a crank sensor to know when #1 is at TDC and the dist cam sensor tells it when #1 is on comp.
Funny but some years of this eng will keep running if you unhook the dist harness after the eng is running. Thats because once the PCM learns when #1 is on comp it dont have to look at it again until a restart. I found this out by accidently unhooking the dist with the eng running. They say if you crank the eng with the dist unhooked it will start but it may take a long crank time as if it dont see a dist/cam sensor signal the PCM will start trying the firing orders until it gets it right and starts. But not all year Mopars will run without the cam sensor signal.
One thing I saw alot was the lower intake plenum gasket blowing out and sucking oil into the intake also.
As for the trans fluid I remember when we started having trouble first in the front drive cars with the 604 (41TE) trans as they can do partial lock-up on the converter and we would see the cars shudder at about 30 to 40 mph from converter clutch chatter. So that one reason the trans fluid was changed to help stop the part throttle shutter from the converter clutch. They used to have us flash the trans controller so it would only let the converter clutch be full on or full off with no partial lock-up. We also had to burnish the converter clutch on new converters on some models.
But bottom line IMO is the ATF+4 will be fine in your trans as we used it in all cars. In fact I use ATF+4 in the 727 in my 63 Sport Fury trans which I built with all Mopar clutches and steel plates and it shifts as hard as any trans I worked with using the ATF+4. Since I worked at a Mopar dealer for 24 years and did trans work I have a few extra bottles of ATF+4 around so I use it in my hotrod and so does my brother and it has worked great in our hotrods. I have had my 63 on the road since 2006 and I still have the same 727 in it and I have never had it out or apart and it still shift great.

I would get a good scanner if I were you as the PCM has good diagnostics in it and with the Mopar DRBIII scanner you could diagnose them so well with all it let you do. Good luck with it.

Last edited by 383man; 11/14/17 09:41 PM.
Re: 1996 dodge van, 5.2 mag. what controls the fuel & timing? [Re: 383man] #2403737
11/14/17 10:41 PM
11/14/17 10:41 PM
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Lincoln Nebraska
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RapidRobert Offline OP
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this high tech is way beyond what I can grasp! If there is an issue I'm gonna tell him to unload it. thanks guys.


live every 24 hour block of time like it's your last day on earth
Re: 1996 dodge van, 5.2 mag. what controls the fuel & timing? [Re: RapidRobert] #2403908
11/15/17 12:18 PM
11/15/17 12:18 PM
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Manitoba, Canada
DaytonaTurbo Offline
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If he's getting 12 in town in a ram van he's doing great. Best I ever got with one of these was 18.5mpg doing 55mph on the interstate in the flatlands of north dakota with the cruise set and no load in a 97 ram 1500. 70+mph dopped me to 12mpg. Sounds like there's nothing wrong with his to me. I agree with dogdays that the worst thing you can do is to start monkeying with it to try to fix a problem that doesn't exist.

Re: 1996 dodge van, 5.2 mag. what controls the fuel & timing? [Re: DaytonaTurbo] #2403952
11/15/17 01:45 PM
11/15/17 01:45 PM
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Lincoln Nebraska
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RapidRobert Offline OP
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I will inform him that 12 is very good & I may have misspoke earlier, I have no plans at this point to (possibly) convert it to carb unless the FI would go bad in the future (tho its worrysome that a system you ain't familiar with could potentially go bad) & everything appears to be good so far on the one time I rode in it (no noises/handles good & he says it starts/stops real good) so all is good in the 'hood. thanks guys.


live every 24 hour block of time like it's your last day on earth
Re: 1996 dodge van, 5.2 mag. what controls the fuel & timing? [Re: RapidRobert] #2404001
11/15/17 03:38 PM
11/15/17 03:38 PM
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360view Offline
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Advise your friend to get his 1997 van into good appearance and running smoothly,
Then sell it and buy an earlier model year van with carb and transmission chosen for reliability.

Maybe when the LA small block in that earlier van is tired, put a Magnum 318 or 360 into that earlier van with a carburetor and appropriate M1/MPI manifold. The Magnum heads will give a slight economy boost, and a noticeable hp boost.

Re: 1996 dodge van, 5.2 mag. what controls the fuel & timing? [Re: RapidRobert] #2404247
11/15/17 10:35 PM
11/15/17 10:35 PM
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Posts: 27,421
Balt. Md
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383man Offline
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Also we have to remember that van is like pushing a huge box down the road so it surely has the most wind resistance of any vehicle which sure dont help mileage. Ron

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