98 grand cheorkee sluggish acceleration ?

[reedboy_1]

Hi,This is my first time posting here so go easy on me I have a 98 grand Cherokee 4,0 engine with the famous inline 6 in it ! 262.000 miles, problem is it takes off sluggish doesn't seem to have as much power as it should just seems like something is holding it back ! , it doesn't have a catalytic converter on it , ive replaced the throttle position sensor , plugs wires , plugs , fuel pump filter and the pump its self , im thinking amm anybody have this problem love my jeep feel bad because it feels bad ,, I drive it every day any ideas guys thanks

 

[Jeepergeo]

Check timing and vaccum? Those timing chains stretch over time....usually the computer can adjust for it but not always. If the timing chain and gears were replaced, did it run ok after?

 

[JPNinPA]

^agree^ start there esp vac leak.


Too much fuel or not enough air can do that.
Check. Dragging brake, bad u joints or wheel bearings.
Does it do this starting cold or only warm?
Any codes or sputtering?


Regards,
JPNinPA

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[reedboy_1]

Timing chain has never been replaced fars as i know , And no sputtering , Have checked all vacuum hoses even had other people look and listen , Nobody hears anything , It drives good runs good no bad ball joints , Its like it dosent have any power , It will go but takes it a little bit to get up to speed , Like when i pull out and start uphill, And it does it right from the get go right after i start it every morning and start up the rd after letting it warm up a few minutes Thanks


Too much fuel or not enough air can do that.
Check. Dragging brake, bad u joints or wheel bearings.
Does it do this starting cold or only warm?
Any codes or sputtering?


Regards,
JPNinPA

Sent using TapTalk[/QUOTE]

 

[JPNinPA]

Check timing as mentioned. You don’t have to hear the timing chain to know it jumped a tooth or two.
Has this been an issue or just start?
Any changes?
Larger tires?

Also with no CAT where is the getting data for fuel trim? Are the O2s in?
Sent from my iPhone using Jeepz.com mobile app

 

[reedboy_1]

Let me fill you guys in on how i obtained this jeep ! my best friends daughter drove it to college for i don’t know how many years , he started having health problems and died two months after i bought this jeep , it had been sitting for prolly 5 years , i put brakes on it all the way around also new alternator and a external voltage regulator, also throttle position sensor , new plugs new wires ! put the same size tires right back on it 235 -75-15. , i work in an autobody shop mine runs better than 99% of the ones that come thru our shop with lesser miles it doesn’t leak oil anywhere i will haft to go borrow a timing light to check the timing , i was thinking it could be the amm correct me if i’m wrong here !

 

[reedboy_1]

Check timing as mentioned. You don’t have to hear the timing chain to know it jumped a tooth or two.
Has this been an issue or just start?
Any changes?
Larger tires?

Also with no CAT where us thus getting data fir fuel trim? Are the O2s in?
Sent from my iPhone using Jeepz.com mobile app

i’ll haft to look tonight see where the o2 are

 

[reedboy_1]

The o2 sensor is put back where the converter was someone just drilled a hole welded the plug back in and screwed the o2 sensor back in !

 

[JPNinPA]

You have any codes?


Regards,
JPNinPA

Sent using TapTalk

 

[reedboy_1]

Only 2, one for the catalytic converter , And one for the wire that goes to the alternator which has been cut ,Put an external voltage regulator on it , And i didnt put the thing between the two wires that go back to the computer thats supposed to kill the check engine light , Anway the two codes are (po622 generator field circuit) ,,And (po420 catalyst 1-1 Efficiency) Hope this helps ,, Thanks <​