Help,..Ram 5.2 Running Bad When Warm

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jaimus

jaimus

Old School ASE Gold
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My Old 98 Ram gots a new problem,...It's a 5.2 (318, 5 speed 4 wheel drive), standerd cab, Long bed,.....I can go about 4 miles till It runs Badly,...Backfiring, no power,No throttle response,......I push in the clutch and she runs fine, rpm's come right up,...let the clutch out and It just falls on Its face,...I checked the distributor pick up plate,...Speed sensor, Cap, Rotor, Wires and Coil have all been replaced,...Fuel Pressure is rock steady 48 psi,...No check engine light or codes,...I'm wondering about the O2 sensor (unlikely), or maybe the cam or crank sensors,...Any Idea's????
 
Holy crap when i seen your title i was going to come in and say fuel pump ....... But with 48 thats not it ...... Im stumped
 
I would think that 4- miles is a bit long before going into cloased loop but it is possible that the upstream o2 (s?) is junk. A cheap scan guage will "usually" tell yo if the upstream O2 is bad. At idle it should be switching lean/rich quickly. Sometimes they fail and get stuck one way or another and other times can get very slow.

Also check your for your belly pan leaking. As the oil warms up/oil thins and more vacuum leaking...

You did check fuel pressure driving down the road at WOT right?
 
Trojmn said:
I would think that 4- miles is a bit long before going into cloased loop but it is possible that the upstream o2 (s?) is junk. A cheap scan guage will "usually" tell yo if the upstream O2 is bad. At idle it should be switching lean/rich quickly. Sometimes they fail and get stuck one way or another and other times can get very slow.

Also check your for your belly pan leaking. As the oil warms up/oil thins and more vacuum leaking...

You did check fuel pressure driving down the road at WOT right?
Click to expand...

yea thats what i was thinking... thats really not the characteristic of that though...
 
Check for diagnostic codes, some parts stores will check for you.

Check the throttle position sensor.
 
Sounds crazy but I had a Jeep acting very similar to this and turned out to be the thermostat.. $10 later and problem was solved...
 
P;ugged It in to a scanner,...Only Codes are for O2, which makes sense cause the cat is gutted,...

We did notice that the AIS reading remained unchanged throughout all the tests,...pulled and cleaned the throttle body, installed a new AIS motor,....life is good,...I think,...She's a fixed.....
 
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