98 1500 5.9 2wd sputters and loses power at idle

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.

quikrete123

Junior Member
Joined
Mar 31, 2020
Posts
3
Reaction score
0
Location
Arizona
Ram Year
1998
Engine
5.9
Hello, first post here cause i'm at a loss. I have a 1998 ram 1500 5.9l 2wd that is sputtering, losing power and what sounds like backfiring when it idles. It only does this when idling and it is intermittent, some times it runs great for a while then acts up. if i stomp on the gas when it is doing this it will come back and run normal but sometimes it lasts longer then others. The truck had an upstream 02 code so i replaced both o2 sensors and no codes now but this is when the problem started. I checked vacum lines and replaced any with cracks or that were broken, took throttle body off and cleaned it, problem sill perssists.

Everything I've seen online points to bad upstream o2 sensor. Just had it at emission check center and it passed but said gas cap was bad, they gave me a free one to replace it.
Is it possible a faulty gas cap can cause this? I don't think it can but you never know. If it is the o2 sensor and its a new one is there a better brand that i should use?
Any help is greatly appreciated. Oh, there are no codes at this time and the problem started a few days after changing the downstream o2 sensor. They were changed about a week apart, upstream first then downstream. Thanks for any input.
 

youtubetech

Junior Member
Joined
Aug 18, 2019
Posts
16
Reaction score
2
Location
usa
Ram Year
1999
Engine
5.9l v8 Magnum
I had the same problem with my 99 ram 1500 5.9l . It turned out to be the intake manifold gasket had given out. Also don't rule out the possibility of the ecm going out

Sent from my GM1900 using Tapatalk
 

bigdodge

Senior Member
Joined
Jan 3, 2014
Posts
523
Reaction score
310
Could be as simple as the pcv valve. If stuck closed it will not idle properly and with mine I also had o2 codes come up. I chased that problem on my 408 for months before my pops said my pcv was sticking and just went and got one even though I disagreed. Has run great ever since.

Sent from my Pixel 4 XL using Tapatalk
 

youtubetech

Junior Member
Joined
Aug 18, 2019
Posts
16
Reaction score
2
Location
usa
Ram Year
1999
Engine
5.9l v8 Magnum
Could be the IAC on the back of the throttle body.
Could be the iac ,tps , or the crankshaft sensor if he ends up replacing to many senors I'll bet it's the ecm

Sent from my GM1900 using Tapatalk
 

Dan98

Senior Member
Joined
Dec 13, 2019
Posts
210
Reaction score
50
Location
Michigan
Ram Year
1998
Engine
5.2
Could be plug wires are shorting maybe rubbing on something or touching something hot. I had one resting on headers burning through and you just described how it acted for me

Sent from my SM-J260A using Tapatalk
 
OP
OP
Q

quikrete123

Junior Member
Joined
Mar 31, 2020
Posts
3
Reaction score
0
Location
Arizona
Ram Year
1998
Engine
5.9
Thanks for all the input, I have an updated situation after having changed the intake and plenum gaskets, IAC vavle, PCV vavle, cap and rotar, plugs and wires, plus water pump, thermostat, vibration dampener, timing cover gasket...truck sounded brand new for about 40 to 50 seconds then i could hear an air sucking sound from somewhere in or around the intake manifold but cant pin it down. engine starts to shake, tremble and sputter, when i give it throttle it makes a loud popping like back fire sound from the right side of the engine if standing in front of it then it stalls out? At witts end with this problem, again any direction or tips would be much appreciated.

I forgot to list the 2 codes that the shop detected, P0132 bank 1 sensor 1 high voltage, P0320 ignition/distributor engine speed input circuit

both O2 sensors have been changed and wiring inspected, changed distributor cap and rotar but NOT the pick up sensor ( which i will change out). need to check the fuel injectors, and engine compression next...?
 
Last edited:
OP
OP
Q

quikrete123

Junior Member
Joined
Mar 31, 2020
Posts
3
Reaction score
0
Location
Arizona
Ram Year
1998
Engine
5.9
Update, got a scanner and when the truck starts acting up it shows running rich and throws P0172 code. I know its the IAC making sucking sound and computer will try and compensate and it comes back to normal operation after a few minutes. cleared codes, and truck ran great for several days and today it started back up with the rough idle??????Anyone have any suggestions, any hlep would be greatly appreciated.
 
Top