1996 dodge van, 5.2 mag. what controls the fuel & timing?

A friend has one & I was wondering what "controls" the fuel/ign so if it acts up we'll know what we might be up against. thank you for your time.

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.

Thank you for the comprehensive info, much appreciated. thats scary stuff! If it acts up & he wants to keep it we may have to convert it back to a carb/electronic dist/mech fuel pump or a low po electric.

Easy to work on and easy to troubleshoot. Don't let it scare you...

run it in the dark and check for old plug wires arcing to heat shields.

Jim, when I read 360views' first sentence I became scared straight. Max, I will check for that the next time he stops over after dark. He said it starts/runs/stops/handles good & his only complaint is the mileage (12 iirc) & on my quick inspection nothing jumped out at me as needing attention. thanks guys.

https://www.ebay.com/itm/1996-DODGE-RAM-VAN-WAGON-REAR-WHEEL-DRIVE-FACTORY-SERVICE-MANUAL/382258712670?hash=item590065105e:g:8EwAAOSwHLNZWvIs&vxp=mtr

Will pay for itself many times

Chrysler also sells a thinner supplement book on
Diagnosing the Electronic Fuel Injection MPI system that has helpful fault guide tables and IF-Then troubleshooting flowcharts

This one is for the V10 pickup
but look for a similar book for the 1996 Ram Van

https://www.ebay.com/itm/1994-Chrysler-Dodge-Ram-Truck-8-0-L-Electronic-Fuel-Injection-MPI-Manual/292150250650?hash=item4405830c9a:g:0uQAAOSwAO9ZQOSr&vxp=mtr

No Mas

I found out it is a '97. I wanted to clean the batt cable terminals but I did not know if you have to jump the terminal to maintain continuity when doing that in order to not mess up the computer?? Also from way back there was something about haveing the injectors cleaned regularly?? is that something that can be sprayed into the throttle body (easy/difficult?) or is that a dealer job?

If you disconnect the battery the PCM computer will "relearn" the fuel injector memory banks and auto trans shift memories over a few hours of driving. A trouble code will be set in PCM computer memory when the battery is reconnected, but the CEL light will not usually turn on continuously just because of that.

Techron Fuel Injector Concentrate Plus
is a good in the gas tank treatment,
as if Yamaha Ring Free.

The injector cleaning rigs that splice into the fuel lines and substitute burnable detergent for gasoline are more expensive but clean quickly.

Taking the fuel injectors out and sending them off for cleaning is typically $25 per injector but they flow test each one. Put the highest flowing injector in cylinder #7. The "catch screens" at the top of each fuel injector get replaced when this is done, probably a good thing.

Moparts members here have built their own pressurized cleaning rigs.

Some owners report that the cheap ultrasonic jewelry cleaners will clean fuel injectors.

Buy new o rings when re-installing.

The one thing that engine was famous fo the coils rusting out the bottom and resulting poor performance or no startAlso for whatever reason many people thought they had plat or 100k Plugs wrong!The vans ran well for the engine size and overall gas mileage was poor they can be a real reliable runner with low maintenance

Good info & much appreciated & I think I am going to leave it (all) alone & hope it stays running good for him but he is my best friend & this is a new acquisition of his so I wanted to be proactive if possible.

12mpg is a touch low if it's highway driving. Plugged catalytic convertor usually biggest cause and next is cleaning both O2 sensors.

Bigger thing to worry about is having fresh ATF4 and filter no later than 60,000 miles. Find out when/if it was done or you'll be under there with Him grunting that sorry-excuse for a transmission out of there. DAMHIK.

12 around town, what trans does it have? I had assumed it was a 727

If it is a high mileage 46RE automatic transmission I would not put current spec Chrysler ATF+4 in it. This new ATF allows the friction surfaces to slip at lower torque.

12 around town is great, there's nothing wrong with it.

360view, would the current ATF cause shudder at idle in gear? I get it on the rare occasion in my truck.

Not sure about shutter at idle with ATF+4

ATF+4 comparison to 3 other ATFs

Kinda technical

https://www.scribd.com/document/96178547/SAE-982674

Sample quote

The results of this evaluation are shown inFigures 5 and 6.
ATF C is the General MotorsDEXRON-III
ATF D is MERCON-V.
ATF D is the Chrysler MOPAR ATF+ Type 7176

End quote

Blazin' Bob,
Put away the axe! You cannot solve any problems on that 1997 van by chopping things up. The computer is so well integrated into the system that it would be more work to try to do without it than to just get things working properly. Most of the time it isn't the computer's fault. They regularly last hundreds of thousands of miles. Chances are that "rebuilt" computer you get at Autozone is used and has been checked for function and put in the box with an AZ sticker on it. Nothing was done to "rebuild" it besides checking function.

That kind of mileage around town is typical. Last year I took a 400 mile trip in a 3/4 ton Ram 2500 4x4 truck and it was mostly highway driving. Truck had approximately 40K miles on it and has been maintained very well. Fuel mileage for the trip was 13.5mpg. I was shocked. I began to understand why people say Dodges eat gas. That truck would be hard pressed to get 11mpg around town.

On a 100K+ vehicle it is not uncommon for the O2 sensors to have started to drift. You won't get a CEL but they are not optimum. They don't cost too much from Rockauto. You can get both from Rockauto for less than $70. I prefer NTK, then Delphi. I have heard (three most dangerous words) that NTK are preferred over Bosch. Delphi is the most high tech of American brands, even though they are GM. I am buying NTK whenever possible.

I'd suggest checking the individual plugs and plug leads using the clamp-on timing light method. Look for any traces of missing flashes. That will give you an indication of a problem. I suppose if you were really serious your friend could chain the van to an immovable object and you could run the test with the vehicle in gear with torque converter at stall speed. This is obviously unsafe and so I am not recommending it to you. I guess a chassis dyno would be the equivalent.

360view's information is worth rereading.

Last point, getting the injectors cleaned and flow matched can't hurt although it feels expensive. One mismatched injector could throw off the whole fuel computation system.

First off for those that read the Tech paper - while it isn't made real clear in the publication - there is a distinct difference in operating systems between Electrohydraulic (EH) versus hydraulic (H) transmissions.
Torque converter controls on the EH allow for clutch modulation which controls slippage from near zero to 60 rpm where the H units do not provide slippage by design. As for actual clutch actuation the same thing applies. EH units monitor and control clutch slippage on the gear change and after. H units apply the clutch but do not provide slippage by design. Friction material did not go through any design or material changes during these fluid tests. As a result control systems did not change either. In short what that means is you will not get any issue going from ATF 3 to 4 on the H transmissions at idle or down the road. H units are 30/31TH fwd, 904/998/999, 727, 42/44/46/47/48 red units.
RFE units fall under EH as do 41,42,62 FWD trans. For guys using the H rwd units note in the pub that using 4 greatly reduces wear - and on the OD units, there are light years differences betweeen dexron and 4 regarding wear.
As for cold fluid viscosity - 4 is the best of the fluids ever used by Chrysler. Reference to "wax". Dennis and Tracey (female) were both sharp cookies. Dennis retired and Tracey left Chrysler for a job at another company - at a great loss to Chrysler.

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.

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.

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.

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.

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.

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