Another Ram truck problem...

[Magnumcharger]

Since the other question was answered so fast, I'll take a kick at the can!

My truck is a 1996 Dodge Ram 4x4 with a Magnum 318 and overdrive automatic.

The situation: While towing my loaded car trailer up a hill, the cruise control suddenly kicked off. I started slowing down immediately, and stepped on the gas.
The engine didn't increase in revs and the transmission didn't kick down. All I got was a hollow "roaring" sound from the engine - similar to sucking on a straw in a milkshake when the cup gets empty. (To me it felt exactly like when the transmission kickdown linkage on my old Road Runner came off the carb).

Finally, as I was on a hill, the truck slowed to a stop.

I put the truck in park, and revved the engine with no problem. Putting it into drive I stepped on the gas again, this time the truck - now in low gear - started to slowly move forward. If I pressed harder on the gas I just got the sucking sound again.

I nursed the truck like this to the top of the hill, then after reaching a level surface, the truck started to pick up speed. After a bit it upshifted to second then third and finally overdrive. Upon reaching the next hill, it wouldn't downshift again and I found the truck slowing down. I couldn't give it any gas more than a high idle and it crawled up the hill. On my first avaliable off-ramp I pulled into a service station and checked my transmission fluid. It was full. I checked the transmission kickdown cable...no problem.

After taking three hours where I would normally take an hour to get home, I parked the truck.

Any ideas?

[Tilar]

Just a wild ass guess, but if it has the electonic throttle control I'd say a throttle controller.  Only reason I'm saying this is because our busses have them and when they go bad it creates the exact same situation you described.

[moparstuart]

Just a wild ass guess, but if it has the electonic throttle control I'd say a throttle controller.  Only reason I'm saying this is because our busses have them and when they go bad it creates the exact same situation you described.

that was my guess the throttle positioning sensor !!!   did it ever jerk or act up on normal hills not towing like it was kind of kicking in and out of  Over drive or passing gear ?   

[gtx6970]

sounds like it was loosing fuel pressure

Just a wild ass guess, but if it has the electonic throttle control I'd say a throttle controller.

96 has a throttle cable as opposed  to the newer Hemi trucks are drive by wire. There for - if it's connected if you push the pedal down the throttle body opens

[Magnumcharger]

Throttle sensor was replaced once. I've heard they carbon up sometimes. I'll pull it out and check it over.
It really does sound like something electronical though.

[Stretch]

It sounds like fuel pressure to me aswell.

[moparstuart]

Throttle sensor was replaced once. I've heard they carbon up sometimes. I'll pull it out and check it over.
It really does sound like something electronical though.

we have had tons of TPS problems on our  94-2000 dodge delivery truck  weather v10, v8 or deisel  all of them go hinky

[ACUDANUT]

May sound simple, but what about the Transmission fluid level ?

[Back N Black]

also, sounds like MAP sensor, it measures load on the engine. in park no load and revs up fine.

[ACUDANUT]

Newer Dodge Trucks have a bad rap with it's transmissions and electrical problems.  Oh wait..It's a Ram and they no longer even say's "Dodge". OR FIAT. 

[Todd Wilson]

96 was the first year for the electronic transmissions.  It very well could be the TPS. If it wigs out it can keep the tranny from downshifting and the TQ unlocking which sounds like something it was wanting/needing to do pulling with the 318 on a hill.    I recommend in the future to shut the OD off when pulling especially with the 318. You will come to find out the truck will pull better and in most cases use the same or less fuel and its not putting a terrible strain on things.

Read here..........

http://www.dodgeram.org/tech/transmission/automatic/TPS_adjust.htm



Todd

[Stretch]

Most of the time the when it's the TPS you will notice a RPM spike here and there. The TPS signal drops out and the ECM thinks you spiked the gas and unlocks the converter. If I am reading the first post correctly it sounds like the more throttle input there is the more power it lacks. I would put a fuel pressure gage on it and see where it's at.

You can check any 3 wire sensor on your car mith a Multi meter. Put the black lead to battery ground, the meter on DCV and back probe the sensor wires with the Key on engine off. One wire will read 12v. this is your power supply to the sensor. One will read about 5 volts. This one goes to the ECM. The other wire is ground. This is the one you want. You should see .10 volts or less on this wire with KOEO. If it's more than .10volts your sensor is bad. The only three wire sensor this does not apply to is some O2 sensors. The ground will show 1 volt or more up to 2 volts. The forth wire is the 12 volt heater wire.

[472 R/T SE]

On my first avaliable off-ramp I pulled into a service station and checked my transmission fluid. It was full. I checked the transmission kickdown cable...no problem.

May sound simple, but what about the Transmission fluid level ?

Whatever Bill says.   

[bull]

May sound simple, but what about the Transmission fluid level ?

Whatever Bill says.   

Right, but he said he checked the level and it was fine.

[ACUDANUT]

Yes he did Bull. I missed it. THANKS

[Magnumcharger]

Just a wild ass guess, but if it has the electonic throttle control I'd say a throttle controller.  Only reason I'm saying this is because our busses have them and when they go bad it creates the exact same situation you described.

that was my guess the throttle positioning sensor !!!   did it ever jerk or act up on normal hills not towing like it was kind of kicking in and out of  Over drive or passing gear ?   

Nope...never did anything unpleasent before it just up and started with this foolishness!

[Magnumcharger]

May sound simple, but what about the Transmission fluid level ?

Fluid level was checked at hot idle, in neutral as per the owners manual. Right on the high level line.

[Magnumcharger]

96 was the first year for the electronic transmissions.  It very well could be the TPS. If it wigs out it can keep the tranny from downshifting and the TQ unlocking which sounds like something it was wanting/needing to do pulling with the 318 on a hill.    I recommend in the future to shut the OD off when pulling especially with the 318. You will come to find out the truck will pull better and in most cases use the same or less fuel and its not putting a terrible strain on things.

Read here..........

http://www.dodgeram.org/tech/transmission/automatic/TPS_adjust.htm
Todd

I guess I should have mentioned that I was towing with the overdrive turned off.

[Magnumcharger]

also, sounds like MAP sensor, it measures load on the engine. in park no load and revs up fine.

I've just borrowed my Father-in-laws' code reader so I'll plug that in and check the faults, if they show up.
http://www.obd-codes.com/trouble_codes/dodge/

[Todd Wilson]

also, sounds like MAP sensor, it measures load on the engine. in park no load and revs up fine.

I've just borrowed my Father-in-laws' code reader so I'll plug that in and check the faults, if they show up.
http://www.obd-codes.com/trouble_codes/dodge/

if you dont have any codes I'd look at the fuel pressure.


Todd

[Beep Beep Dave]

I'll say the Cats plugged up...

Dave

[Stretch]

 A plugged cat is very posable. I've seen alot more pluged cats over the last year or so in my shop. I'm not 100% sure it doesn't have somthing to do with the changes being made in the gas formulation.

The ethanol in the "new" gas plays hell on small engine carbs. It evaporates and plugs the pilot port in small engine carbs in about 30 days here. (michigain). If it's that bad for the carb it can't be good for the catalytic converter.

Very good point Beep Beep Dave!

Jason

[TXcharger70]

I agree it could be your cat. I used to have a 96 2x4 318 and had that happen to me as well. But then again i had the same type of symptom when my tranny was going out

[Todd Wilson]

Well what did we find out?


Todd

[Magnumcharger]

So far I haven't been able to get back to look at the truck. I'm hoping this upcoming long weekend.
Several things I'm going to do immediately:

1. Check the TPS2. Check the ECM reader
3. Check the catalytic convertor
4. Check the Throttle (kickdown) control cable to the transmission.

[Todd Wilson]

The CAT's of that era had problems. Some even were recalled.   My 95 CAT used to rattle and kinda buzz on aceleration.   I had it replaced under warranty. Something about the guts inside come loose and can plug up.


Todd

[Beep Beep Dave]

Well did you figure it out yet Robin?

Dave

[Magnumcharger]

Not yet.

But this is what I've done:
I used my OBD-II reader to do a simple diagnostic while running, and got no codes or faults.
I removed the idle control valve, cleaned it, did a check on the functioning circuitry with no issues.
My Cat doesn't appear to be clogged, although I may drill a hole in it to "relieve it" of any possible "internal restrictions".
I checked the Throttle control valve, removed the aircleaner and ensured the kick down cable is functioning.

All that, and it's still not working properly.
I've had a sticky TCV previously, and that's not it for certain. Also, the transmission was rebuilt three years ago when it wouldn't go into reverse or high gear.

My brother-in-law has a similar Ram, and experienced the same thing. His rectification was to change out the ECM.
I'm thinking that might do the trick as the tip-off to my issues was the immediate loss of cruise control. Since this is an electronic controlled transmission, the ECM could well be the culprit.

Meanwhile, I've got the truck in the garage and I've welded some patch panels on the box sides and will be putting on a new set of front fenders this weekend upcoming.
It's an old truck, but it's paid for and has been good to me. So it deserves an extension on life.

[Stretch]

Check the TPS.

You can check it with a multi meter two ways first KOEO 12v scale, neg. to the battery neg. Back probe the sensor with the pos. One of the three wires will show 12v. Thats your power supply to the sensor. one will show 5 volts or slightly less, this is the signal to the ECM. The other wire is the one you want. It's the sensor ground. You want to see less than .10 volts. Anything more than .10 volts on this wire means the sensor is bad.  You can use this simple test on ANY three wire sensor. After you do that test you can check the sensor through its range by checking for a voltage drop as the throtle is opened. This test is easyer on a scanner (not a code reader) if you have one. Your looking for a point in it where the signal drops out.

[Magnumcharger]

Stretch, I'll do exactly as you said this upcoming weekend.
As a matter of fact, I had printed out this very inspection two weeks ago but hadn't done it.

I guess I'll have to now!

[Magnumcharger]

Alrighty then.
Months later, I'm getting back to this thread to update it.

The problem was.....a plugged Catalytic convertor!
Todd Wilson, you win the prize. Whatever that might be.

I replaced the TPS and the Speed sensor too, to no avail!
I took the truck (at 30mph - maximum speed) to a local repair shop where the mechanic knew EXACTLY what the problem was.
When I picked it up afterwards, I expected a massive repair bill, after all, Catalytic convertors aren't cheap!

But no! He opened it up, dumped the contents, and rewelded it up. Good man!
Problem solved. The truck runs like a superstar now.

On to the next problem: an exhaust manifold bolt which has mysteriously gone missing out of the very back bolt hole on the right side. And now exhaust is pumping out of it. I've seen coolant coming out of this hole on older small blocks, but these Magnum V8s must be a different animal.

[moparstuart]

Alrighty then.
Months later, I'm getting back to this thread to update it.

The problem was.....a plugged Catalytic convertor!
Todd Wilson, you win the prize. Whatever that might be.

I replaced the TPS and the Speed sensor too, to no avail!
I took the truck (at 30mph - maximum speed) to a local repair shop where the mechanic knew EXACTLY what the problem was.
When I picked it up afterwards, I expected a massive repair bill, after all, Catalytic convertors aren't cheap!

But no! He opened it up, dumped the contents, and rewelded it up. Good man!
Problem solved. The truck runs like a superstar now.

On to the next problem: an exhaust manifold bolt which has mysteriously gone missing out of the very back bolt hole on the right side. And now exhaust is pumping out of it. I've seen coolant coming out of this hole on older small blocks, but these Magnum V8s must be a different animal.

it didnt break off did it ?  they get hot and love to do that on those 

[Stretch]

Don't tell to many about the coverter fix. It's against federal law to do that. That could be a big fine for that shop.

[moparstuart]

Don't tell to many about the coverter fix. It's against federal law to do that. That could be a big fine for that shop.

are canadian laws the same   

[Magnumcharger]

Don't tell to many about the coverter fix. It's against federal law to do that. That could be a big fine for that shop.

are canadian laws the same   

Nope. We're in the wilderness, remember?
Seriously though, nobody is doing smog checks on our vehicles here. Population density is pretty low.

[ACUDANUT]

 

[Beep Beep Dave]

I am pretty sure I called it first...man how do you get any respect around this place 
I guess I could keep those prudy Keystones

Ok I will take another 100 or so pages of Cars in Barns pics You still have my email?

Dave

[Magnumcharger]

I am pretty sure I called it first...man how do you get any respect around this place 
I guess I could keep those prudy Keystones

Ok I will take another 100 or so pages of Cars in Barns pics You still have my email?

Dave

Dave, I blame my lazy 'clicking' finger, which only clicked on the second page, rather than crawling through the entire thread!
Keystones? Oh yeah, THOSE Keystones!!
Alright. You win the prize!!! Congratulations!! Todd, you're now in second place!

I'd love to give you another 100 pages of Cars in Barns content! I have to get back out to Alberta first! Nova Scotia just doesn't have good enough junkyards!!

[Stretch]

We don't have smog checks here either but modifying the cat hits federal laws does it not? I'm not sure how that would apply to the Canadians but I bet the law is similar.

Here the police can (and do) stop you for something like loud exhaust and "look" at your exhaust system. No cats or a cut and welded cat is a $2000.00 dollar ticket per cat! You get 14 days to fix it. If you do and get it inspected the ticket is cleared. The fine for shops (that get cought) is much higher.

All I'm saying is the less people who know, The better off everyone will be.

P.S. I'm glad your truck is fixed. and I'm dong this to mine...

http://www.frozenboost.com/product_info.php?cPath=210&products_id=329&osCsid=4509bb2099c94ec52e53cdbd0f34441e



As for the down stream O2. I'll buy a "weld in O2 bung" and put it into the frame rail of the truck or if there's room I'll drill a hole in the outer shell of the cat (not into the exhaust stream) and put the sensor there. It's looking for the cleanest air it can see anyway. This will keep the check engine light out.

[nvrbdn]

taking it off the truck and welding it back up is not altering the converter. my son called me one day after a fishing tournament saying his blazer had no power. i said dont drive it and hooked up the trailer heading an hour south to get him. when we got there the truck fired right up and drove it on the trailer. well on the way home he told me it had been acting that way for a few weeks. fine in the morning, but after driving a little it lost all power. well that didnt sound like a timing chain so i called a buddy and was told to check the cat convert. i got it home and put it on the livt and cut the cat out and instant power. i looked into the cat and it was blocked solid. shone a light through one end and couldnt see nothing.  used the compressor and blew it all out. looks like a honeycomb on the inside.when i got done, you could see right through it. welded it back in and been 2 years and runs perfect still. and has passed emissions too.

[Stretch]

How is removing the catalyst from the catalytic converter not altering it?

[nvrbdn]

i guess i misread his post. i was thinking he had it cleaned out, not removing the entire guts. thats what we did was remove, clean it out, and reinstall it.  my bad.

[Stretch]

No big deal. Hell, Perhaps I misread it.  I have been known to jump to conclusions.

[nvrbdn]

 

[Stretch]

The reason why I'm going with the "cat" I listed the link for is I want the apperance of having one and I'm sure the stright through disign of that one must flow better than a hollowed out converter. I'm sure a hollowed out converter causes alot of turbulence in the exhaust stream. If I'm going to go through the work I want to make it wrth my time.

[Todd Wilson]

The problem was.....a plugged Catalytic convertor!
Todd Wilson, you win the prize. Whatever that might be.

Thank Me!!!!!!!!!       


Todd