95.5 3.2 v6 runs rough @ 2k rpms

[H2odrx]

hello all, i've looked at alot of coolant sensor post and egr post and am not sure if i going the right way or not. It starts and runs but sounds as if it has a miss, then when you drive it it is ok until it levels off to 2k rpms then it feels like it is going to come apart? I will look into changing the fuel filter, plugs, and wires 188k miles so it might be due? anything i am missing?
thanks

[trooperbc]

Originally Posted by H2odrx

hello all, i've looked at alot of coolant sensor post and egr post and am not sure if i going the right way or not. It starts and runs but sounds as if it has a miss, then when you drive it it is ok until it levels off to 2k rpms then it feels like it is going to come apart? I will look into changing the fuel filter, plugs, and wires 188k miles so it might be due? anything i am missing?
thanks

you and your truck are missing....ignition coils.
perhaps. like you know, it's fuel or ignition. you can get a cheapie ignition tester from one of the bigboxpartsstores. or use an iductive timing light. since each coil ignites two (2) cylinders if you find 2 that are missing from the same coil, you can replace just that coil or do the whole coil/ignition module assembly.

the symptoms you describe could easily be the coils and they can be intermittent as well as load-influenced.

yet, as i'm typing i'm thinking about the
egr and the exhaust gas backpressure transducer.
the bpt helps control the vacuum supplied to the egr. there's a little vacuum-looking line that goes between the bottom of the egr to/from the bpt which supplies the bpt with a sample of the exhaust gas pressure. this little line at the egr gets clogged with exhaust residue, sometimes only partly clogged. on my 1992 trooper this turned out to be the cause of a mild by annoying hesitation/miss at ~3000 or so rpm, even though the egr passed all the oncar visual and vacuum tests.

so there's two ideas. i'm still leaning to the ignition coil(s), but you will have to test and decide.

//bc

[H2odrx]

Ok that was my first idea, coil packs. I have gotten the egr code 32 so check the hose from the egr to the bpt, is there a part number if it needs replaced? i plan to check more in the morning.
Update....

Ok i changed the oil, pulled the plugs they looked good but needed gaped were .55? went ahead and installed new .44, then changed fuel filter. it seems to run ok for now?

[trooperbc]

Ok i changed the oil, pulled the plugs they looked good but needed gaped were .55? went ahead and installed new .44, then changed fuel filter. it seems to run ok for now?

well that 's good...

Originally Posted by H2odrx

Ok that was my first idea, coil packs. I have gotten the egr code 32 so check the hose from the egr to the bpt, is there a part number if it needs replaced?

a good resource is the isuzu online parts site. official. full on parts illustrations of *all* the parts. and parts numbers etc.
www.myisuzuparts.com

the line i call exhaustsampling goes from near the bottom of the egr to the bottom of the bpt. it's shown here in the illustration from the parts site. let's make sure: this is the kind of egr valve in your 95.5, correct?(marked --' 12/95 'SEE FIG NO. 0-57' in this illustration).
if

if so, continue. if not...stop.
the line i'm talking about is the *metal* part that hose labeled #56 attaches to at the bottom side of the egr valve. it will probably be worthwhile for you to clean that metal line with 02sensor-safe cleaner and a piece of wire. if that doesn't solve your egr CEL, remove and clean the egr, it's pretty simple to do.

//bc