Engine/Transmission (1994 - 1998) Looking for new ideas...

[KMott]

I am still trying to figure out why my 94 ram doesnt seem to pull like it should. It is an automatic and im assuming that means it has a 160 pump.



I should be able to keep up to a 91 stock cummins dually. I have replaced multiple parts (overflow vavle, all fuel lines, shutdown solenoid, filter, etc)thinking it was a fuel delivery problem (which was part of problem) but it still doesnt run right. After road testing it today with a fuel pressure gauge on it, fuel pressure checked out good.



So I read through 5 or 6 pages of old topics and found a few about the 'AFC' causing problems. What exactly is this and how can it be checked? Thanks

 

[Matt42]

Check the adjustment of the throttle rod. That's the thingy with ball sockets on both ends that connects the throttle cable from the pedal to the fuel pump. It has adjusting nuts that can loosen, and prevent full operation of the pump.



This happened with my 1996, and it was a quick roadside adjustment with a couple of 10 mm combination wrenches and the factory TSM.

 

[Extreme1]

It's best to have someone inside pushing on the pedal too because if the cable isn't adjusted right you will set it under the hood and still not have full travel. Don't ask how I know this...



If the sockets are dry and sticky the lever assembly will "overcenter" (FSM term) prematurely and you'll still miss it with everything adjusted right.

 

[Howard Durand]

The 94 fresh out of the box is not much to brag about in performance but it has potential. Moving the AFC star wheel forward about 30 clicks will help the early response but to really realize it's potential will require a number of other enhancements as well. Get some gauges first then ask questions. There are people here that are very informative and will be happy to help you along. I started out with a Banks Power Pak which made a big difference. Folks put Banks stuff down as too expensive but I had no other option at the time. Now, with this forum, you can sort through the different levels of advice and recomendatons and, using a level head, you can probably come up with a pretty nice pulling machine.

 

[KMott]

I checked the throttle cable and it checked out good. It had fully rotated the sleeve and was just starting to turn the spring. I just had the cable replaced by chrysler when they did the last 4 recalls on it, so i figured it would be ok.



Im thinking maybe Howard is right, maybe this is all its got stock. I just dont want to start modifying something that isnt running right stock, and i have also driven a couple first generation trucks that seemed to pull a lot harder.



Either way im going to do a few more tests and if all is well then i am going to invest in some gauges and then go from there.



Right now im trying to figure out why the thing wont warm up right. I drive an hour to get to work, and the gauge barely moves up from 60 unless i slow down a bit, and as soon as i speed up it drops back down close to 60 again. I just replaced the thermostat with a uap one, because the old one was stuck open. Maybe the new one is bad too, i cant think of anything else that would cause it to not warm up.



Thanks again.

 

[Howard Durand]

It should do more than you are getting. Mine wasn't too bad when it was stock except for the lag on takeoff. Moving the star wheel helped that.

The Banks kit helped a lot. Basically all it provided was an upgraded plate, different turbo exhaust housing, a larger exhaust and gauges. All of which can be bought separately from different vendors. I later changed out the injectors, increased timing and have replaced the gauges with Westach. If you get carried away, your next problem will be the transmission.

As to the problems at hand, Make sure the intercooler boots are all tight. A boost leak can cut your power. If you can't get it to heat up, check the fan. It may be engaged all the time. It is probably still cold in your area. If so, slide a piece of cardboard between the AC cooler and the radiator.



A couple of your countrymen that you may want to get acquainted with are Piers Harry at PDR and Bill Kondolay at DTT. They will talk to you and give good advice.



Howard

 

[Joe G.]

The quick and easy test for the AFC is to take it off and see what happens. If the AFC is not working then doing anything with adjustments like the star wheel will have no affect. Take if off and tie it up out of the way. Cover the hole with something and go for a ride. The AFC is a throttle stop. It prevents overfueling (black smoke) until there is sufficient boost to move it out of the way. Until that happens you can't get full throttle. The star wheel controls how much boost it takes to move the throttle stop. If no boost is getting to the AFC or it's stuck any adjustments won't work.

 

[KMott]

After i found it was going to be raining all weekend ( i dont have a shop to work in) i decided to drop it off at ML truck and tractor service. He took it out and thought it was running ok until he hooked a trailer on and retested it. Sure enough, after that he got looking and i guess the AFC was where the problem was. He said the diaphragm was bad in the pump. So basically as you guys said, the pump isnt getting the boost signal to open the fuel up all the way because the diaphragm is bad. He ordered the part and will have it done for monday. Hopefully this does it! Thanks again for all the help

 

[KMott]

I got the truck back today, and it runs exactly the same. They replaced the diaphragm in the pump, and they told me on the phone they were replacing another diaphragm on the wastegate, and it turned out the be the wastegate diaphragm and actuator (i think thats the whole wastegate??) Anyways if these things were bad, why wouldnt they make a difference being fixed, lol? 700 dollars later (i was expecting a few hundred max) its still gutless!! Dont get me wrong, im friends with the owner and i know he is a real good guy, i just dont see why it made no difference at all unless there is something else that is overruling all these little problems.



So tonight, at work during break i pulled the rubber line off the afc housing and put a bolt in the line. The truck had no power at all when i did this, so i have to assume the afc is functioning, and was before they fixed it. I also disassembled and cleaned my pre-heater filter at lunch break (i hope this helps to show you how much this truck is bothering me, lol)



With the starwheel being turned up, and having good fuel pressure, shouldn't this thing atleast put out a little bit of black smoke?? It never does, not at startup or when i floor it. Thats why i still think there is a problem (that and lack of power) For example, going up a medium grade hill, tc locked (o/d) 90km/h, floor it and by the time i get to the top of the hill i might be doing 92.



So the last thing i can think of is either injectors or injection pump. M+L told me they could send the truck away to the injection shop to have to fuel turned up, but it would be another 200 or so dollars to have it set properly. And getting the injection pump bench tested will probably be even more. Im running out of ideas, and looking for some input here. I jus want the heap to run right!

Thanks again!

 

[PSchwering]

When I got my 94, (auto, 160HP) My Buddies Stock 92 5 speed would leave my 94 in the dust. As it turned out, My 94 has 3. 55 gears, & he has 4:10. His 5 speed has a higher HP rating than my Auto, plus you lose some go power through the stock torque converter. I was so bothered by this that I arranged for & had mine run on a Dyno. turns out, I had 155 HP at the rear wheels. Not to bad for a 160 engine HP truck. In Stock form, I could see absolutly no Smoke. The only way I could get a small puff was to use the TC lockup switch to lug the engine under 1000 RPM.



I guess in Summary, what you describe as "Underpowered" seems pretty normal to me, based on my experience with a 160HP automatic. Heck, When stock, I could only pull my 27' Fifth wheel about 55 MPH Tops. That was all the power it had.

 

[KingS]

why haven't you guy told him the free hp mod for his truck as in fuel plate adjustment and afc adjustment as in sliding every thing foward and then star wheel adjustment he will love the truck then

 

[Turbo Thom]

He want's to keep it stock. My 94 dyno'ed at 367, with my messing with it.

 

[KingS]

well then that would answer it then

 

[Howard Durand]

He needs a couple of gauges first, boost and EGT. I know that a boost leak can give problems. I found one of the boots had worked out from under the clamp which made mine pretty sick even with the #5 plate.

Not getting black smoke is probably not a sign of problems if the stock plate is in it's stock setting. If you want to experiment with the plate, I would be glad to send you the plate that came with my Banks kit along with the instructions on how to install it.

I certainly don't need it anymore. In the process, you could make sure the governor lever is adjusted properly. You can find instructions for that at Piers' web site.

If you want the plate, send me a PM.



Howard

 

[MLee]

why haven't you guy told him the free hp mod for his truck as in fuel plate adjustment and afc adjustment as in sliding every thing foward and then star wheel adjustment he will love the truck then

But if you want to stay stock then the advice you have received is to fall on deaf ears. As stated by "KingS", doing these things are a no cost way of getting a little more go, with no expense. The timing could use a little help, to about 16*. I pulled my #5 plate out to save my clutch, and had to do trial and error to get it to run acceptable again, a step at a time. And it ran as yours is doing now. NO the #5 is not for sale. Quit giving the shops all that money, for doing nothing!

just my penny's worth.

Marv.

 

[Howard Durand]

I was under the impression that if he can't get better performance with it stock, some upgrades would be considered.

I do know that when climbing a hill, floorboarding it does not help. It just unlocks the TC, kicks out of OD and there you are, full rpm and no speed.

Try locking out OD before starting out. Then let it go into OD when speed and RPM are up. The 47RH and TPS combination have a tendency to shift into OD too soon.

 

[Turbo Thom]

OK... ... Me see... ... Me hush.....

 

[Howard Durand]

Turbo Thom, no need to hush. I think KMott would like to keep it mostly stock but I am thinking that it just won't live up to his expectations. Mine was somewhat a disappointment at first, compared to the 92 I had traded in.

The Banks kit, although more expensive than necessary, was a moderate improvement that made the truck perform much better. That is why I offered him the Banks plate. It is not near as agressive as the #5 I am using now but it really did pull nice with much less worry about egt.

 

[KMott]

Thanks for all the input, and thanks for the offer Howard (may take you up later when i get some ideas on where to go with it). Im starting to think maybe you guys are right about the way its running. By the way, when i was talking about going up the hill, the truck doesnt d/s if i floor it, it stays in lockup. Ive had mixed opinions from people who have driven it. My uncle drove it and he said it didnt pull near as hard as his 92 gmc 6. 5L, which didnt seem right. But i guess those 6. 5's are bigger engines, and there downfall is obviously that they blow up all the time, lol. Other people thought it seemed about right.



Anyways i don't plan to keep this truck stock at all. I just want to have it running where it should be before i start modifying it. I plan to get it up to about 250 hp, and limit it at that for the transmissions sake.

(I have an 86 chevy with a 5spd stick (cast housing) that im putting a 1st gen cummins motor into. I know i can take that thing as far as i want, becuause those old drivetrains are bullet proof, and parts are cheap as dirt)



Im going to order up a set of gauges before the weekend and then once i get them installed ill post again and get ideas on where to go from there. Any suggestions on where to buy gauges? Thanks again.