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supertech, mastertech
Category: Car
Satisfied Customers: 2251
Experience:  ase master auto tech,triple chrys master tech,42 yr experinece,adv. level spec. ASE. HEV chrys spec.
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dodge: 3.9L..First it was backfiring and hesitated at all speeds.

Customer Question

I have a 3.9L dodge ram van 1500. The problem was twofold. First it was backfiring and hesitated at all speeds. Went to shop had a fuel injector cleaning, after i looked at plugs and noticed #3 showed not firing. Then i checked for spark @ #3 and showed no spark but spark at all other cylinders. So i replaced Cap, Rotor and wires. Test again showed spark at all cylinders. Test drive gave no more backfire but at stop idle is somewhat rough and from stop i get a slight hesitation. Which if you give gas it gets a possible stall, but if you slowly give gas it responds and takes you to 2nd. Oh i have a 3speed automatic. and the year make is 2002. I am not sure where to begin next. I hear that it might be O2 sensor, or drive train control module, possibly throttle position sensor,maybe even the throttle body itself needs to be cleaned? but i would like some direction of which of these i should work on next?
Submitted: 8 years ago.
Category: Car
Expert:  supertech replied 8 years ago.

Hi my name is john.

I take the air cleaner off and open the throttle body and look in at the bottom of the pleum to see if there oil in there.

the throttle postion sensor will cause the hesitation.

i just want to make sure it isn't full of oil.

I would clean the throttle body also at the same time when you replace the throttle postion sensor.


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Customer: replied 8 years ago.
i know i am answering this way late but just so everyone is aware the reason for my problems is in the #3 cylinder. After i gave a pressure test it was the only one that failed. Therefor i need to remove head and i will probably see that a valve is bad. Or if i am really lucky i will only need to replace a head gasket. Unless there could be another reason for this cylinder to fail pressure test.

thank you all