2002 Dodge Dakota - 3.9L Intermittent Bogging

[1stephen2]

We have a 2002 Dakota that intermittently bogs down upon acceleration, sometimes to the point of stalling. If you floor it, it back fires through the intake and throws you back in your seat. I've got good fuel pressure, vacuum, oil pressure. We replaced spark plugs, wires, distrbutor cap and rotor. We also treated fuel with injector cleaner.

There are no codes present and no engine light.

Any ideas would be greatly appreciated.

[fortknoxx]

egr?

[protraxrptr17]

Yep, I would look there first. What are your trim numbers?

[brianp87]

Yep, I would look there first. What are your trim numbers?

Yep fuel trims

[steven kiser]

a pop during acceleration is usually a lean pop. fuel trim is important. if rear 02 is reading rich the pcm will force lean causing this issue. is this year involved in the chrystler converter recall? for some reason i'm thinking that this may have had the parameters reset to allow a broader range to stop a check engine light issue. i remember questioning the feds allowing the spec change as opposed to the cat replacement. the years are running together for me and sometimes my time lines are way off.............

[Jeff @ Able Auto]

I would also check the intake floor gasket for leakage. When I worked for Chrysler we saw a variaty of problems caused by this. Look down thru the throttle body checking for excessive oil in the intake.

[1stephen2]

sorry for the late reply, but 02 dakota has no EGR valve, it has a leak detection pump and filter instead. I found cracked vaccuum lines from the filter to the pump. I was also directed to the fuel rail because it has only one pathway and may be clogged at a couple injectors. this is bossmans truck so labor is somewhat free, so I'll start with the fuel rail and injectors(no cost) and then replace the ldp filter and line (about 20 dealer cost) Thanks again for all replies

[steven kiser]

a bog issue because of a restricted injector is highly unlikely. it would remain not recover. as stated look into the throttle body for any sign of oil. another easy way of testing for an intake leak is take pcv out, plug hole, take oil cap off and place your hand over the port. if you feel any amount of suction the plate gasket needs to be replaced. if it's the bosses truck and it's good then maybe after the issue is resolved you may want to suggest that it should be replaced. this gasket would cause a symptom similar to what you describe but a rough idle would be there as well. a restricted i.a.c. may cause an issue like this. i would also with my scanner hooked up and key on engine off watch the t.p.s reading very closely for a voltage drop. i strongly suggest a slow pedal depression more than just a few times. i use my hand, i get better control that way. i hope your scanner will allow you to control certain sensors, the i.a.c. being one. see if the % remains constant while opening and closing with the vehicle r.p.m.. if the % shows 0 and the r.p.m. isn't base or close to it either clean it along with the port or replace it. either way clean the heck out of the port and blow around in there with a blow gun. if this owners truck is like mine, you're in for a run. the cobblers kids are the ones with no shoes....... i mean it. i'm a plate slapper. if what ever i'm driving starts to run so bad i won't drive it, off the plate comes and i look on the lot to see what i want to drive now.

[brianp87]

Yep, I would look there first. What are your trim numbers?

Yep fuel trims

[1stephen2]

Replaced leak detection pump filter and line and cleaned out fuel rail and replaced injector o-rings. still have same issue. checked intake for excessive oil in pan, looks good. also performed test described in post and there is no suction felt. checking fuel trim and o2 sensors next.

[steven kiser]

checking fuel trim and o2 sensors next.

made me reread the thread and was surprised to see that they weren't checked before. i again assumed that the basics were covered. i stuck down steam 02 reading rich will force lean. a worn cam or bent push rod will cause a pop during acceleration. is the idle smooth? if so i would recheck the tps reading during slight acceleration.....