94 1500 5.2 no acceleration on rpms

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

Michael barnette

Junior Member
Joined
Mar 16, 2020
Posts
10
Reaction score
1
Location
Arkansas
Ram Year
1994
Engine
5.2
I have a strange issue as my 5.2 idles fine but when accelerator pedal is pushed starts backfiring and loosing rpms til it dies if you hold the pedal down. Can’t get over 2000 rpm. Any help is appreciated.
 

muddy12

Senior Member
Joined
Jul 26, 2016
Posts
1,030
Reaction score
800
Location
Indiana
Ram Year
2012
Engine
5.7 Hemi
Does it still have factory catalytic converter?
I had a 93YJ that did the same thing when the cat became plugged.


Sent from my iPhone using Tapatalk
 

KeepRight

ExFalconFxr
Joined
Jun 18, 2018
Posts
328
Reaction score
190
Location
US
Ram Year
2015
Engine
EcoDiesel
I have a strange issue as my 5.2 idles fine but when accelerator pedal is pushed starts backfiring and loosing rpms til it dies if you hold the pedal down. Can’t get over 2000 rpm. Any help is appreciated.
Let's maybe go down a short list. Does it throw a code?

Cat converter clogged
Clogged/Bad fuel injectors
Clogged/Bad fuel filter
O2 sensors
Bad or loose throttle control connection

Doubtful - needs tune up... Plugs, wires, etc.

Holler if I can help...
 
OP
OP
M

Michael barnette

Junior Member
Joined
Mar 16, 2020
Posts
10
Reaction score
1
Location
Arkansas
Ram Year
1994
Engine
5.2
It has the obd1 setup and I can’t retrieve codes. Truck idles great- no missing or rough idle. I just bought the truck and it ran good when I first got it but now won’t go over 2000 rpms. I’m going to try a fuel pump and if that doesn’t work I’ll be lost as someone changed the exhaust system and it has the upstream o2 sensor but not the downstream one. Runs good when first starts but can’t accelerate after a couple of minutes running.
 

JohnnyMac

There are no stupid questions, just stupid people.
Military
Joined
Mar 31, 2018
Posts
2,558
Reaction score
2,920
Location
SouthWest Washington
Ram Year
2018 1500 Laramie
Engine
3.0 EcoBurner
I agree with the other folks. If those don't work, I believe you can unplug the upstream O2 sensor and if it runs better, then it's a sensor issue. Another problem may be the Throttle position sensor. Those can cause lots of problems with timing, air/fuel mixture, etc. If it is causing the truck to run too rich, that can not only make the truck run like crap but can ruin your catalytic converter too. May have multiple problems. I would also pull the cap/rotor and make sure the contacts don't have a bunch of buildup.

Good luck and let us know what you figure out.
 

KeepRight

ExFalconFxr
Joined
Jun 18, 2018
Posts
328
Reaction score
190
Location
US
Ram Year
2015
Engine
EcoDiesel
It has the obd1 setup and I can’t retrieve codes. Truck idles great- no missing or rough idle. I just bought the truck and it ran good when I first got it but now won’t go over 2000 rpms. I’m going to try a fuel pump and if that doesn’t work I’ll be lost as someone changed the exhaust system and it has the upstream o2 sensor but not the downstream one. Runs good when first starts but can’t accelerate after a couple of minutes running.
Fuel pump is definitely on the list... But one of the most expensive. I'd prob look into the fuel filter first; can't hurt ya know.

That too the o2 sensors... Way too much money. You might swap o2 sensors around... I know, that's prob waste of time. Those damn things were over $100.00 each for my older suburban.

Not sure why you can't pull codes. Swing on over, you can borrow my older scanner.... Does it have a check engine light? You can count the flashes...

Again, holler, I'll help the best that I can.
 

muddy12

Senior Member
Joined
Jul 26, 2016
Posts
1,030
Reaction score
800
Location
Indiana
Ram Year
2012
Engine
5.7 Hemi
Since it’s OBD I, there should be an on/off sequence that you can cycle the key, which will cause the check engine light to flash/blink the code. That’s what I had to do with my 93, as it was OBDI as well, and did not have anywhere to plug in a scanner.

Just FYI. OBD II (as well as the standardized diagnostic plug) didn’t start until 1996.

Also, if I remember correctly, the only fuel filter on the second gen’s, is the sock on the end of the fuel pickup, which is attached to the fuel pump located in the tank. You have to either drop the tank, or pull the bed.
Sent from my iPhone using Tapatalk
 
Last edited:

muddy12

Senior Member
Joined
Jul 26, 2016
Posts
1,030
Reaction score
800
Location
Indiana
Ram Year
2012
Engine
5.7 Hemi
It has the obd1 setup and I can’t retrieve codes. Truck idles great- no missing or rough idle. I just bought the truck and it ran good when I first got it but now won’t go over 2000 rpms. I’m going to try a fuel pump and if that doesn’t work I’ll be lost as someone changed the exhaust system and it has the upstream o2 sensor but not the downstream one. Runs good when first starts but can’t accelerate after a couple of minutes running.

Was the catalytic convertor removed as well, or does it still have one?
 
OP
OP
M

Michael barnette

Junior Member
Joined
Mar 16, 2020
Posts
10
Reaction score
1
Location
Arkansas
Ram Year
1994
Engine
5.2
Still has the converter but it looks like someone cut out the pipe past the converter or the downstream o2 sensor and put in a piece of pipe the join the exhaust together
 

muddy12

Senior Member
Joined
Jul 26, 2016
Posts
1,030
Reaction score
800
Location
Indiana
Ram Year
2012
Engine
5.7 Hemi
Unless the converter has been gutted, my money is on the cat being plugged.


Sent from my iPhone using Tapatalk
 
OP
OP
M

Michael barnette

Junior Member
Joined
Mar 16, 2020
Posts
10
Reaction score
1
Location
Arkansas
Ram Year
1994
Engine
5.2
It was the fuel pump- it runs fine now. Thanks for the help. Now on to the slow shift issue and frontend looseness
 
Top