Boggs down under acceleration

1995 Grand Cherokee Laredo 4X4 300K miles 5.2L V-8

I have a Cherokee that starts fine, idles ok in park, but boggs down under acceleration.
It runs ok up speed, but you need to hold the gas and the brake to keep it running, say at a red light.

I put my head under the hood, there are no obvious problems, but I have no history of the vehicle. I'm just helping someone out.

Would the throttle positioner sensor do this? If the fuel injectors were bad it would not idle ok in park, would it?

Any info is appreciated.

Russ

Hey Russ, Welcome to AF.

On the older 5.2L V8s, timing chain stretch would account for the problems you noted. However that's been mostly cured on the newer models. But with 300k I would consider replacement.

Other things that come to mind: spark plugs. Bogging down is often a symptom of electrical wear and tear....with older vehicles the plugs, cap and rotor would contribute to this issue. I don't know if this year has plug wires, cap and rotor, but replacing those should help if you have them.

Post back after you've had a look at this stuff and let us know how it's doing.

Thanks for the greeting, I didn’t think about intro’ing myself. :)

I was thinking the timing was sluggish also. I doubt any maintenance has been done at all. The plugs may be worn to a nub. I was thinking the throttle position sensor could be worn.

My uncle is 79 and bought the SUV because of the body style, he doesn’t even consider the mileage when he buys! Plus he is incapable of working on it.

I will post back if I hear what he does to it. Thanks

Other things that come to mind: spark plugs. Bogging down is often a symptom of electrical wear and tear....with older vehicles the plugs, cap and rotor would contribute to this issue.

I agree with a tune up, including wires, cap, rotor, spark plugs, fuel filter, and air filter. By all means, do the work yourself and you'll save a bundle. I replaced the cap, rotor, etc. on my 1994 GC at about 120000 miles when it began to sputter and it made a big difference. Now at 218000 it's still running well.

Other things that come to mind: spark plugs. Bogging down is often a symptom of electrical wear and tear....with older vehicles the plugs, cap and rotor would contribute to this issue. I don't know if this year has plug wires, cap and rotor, but replacing those should help if you have them.

Thats very true, the plugs would help the situation out very well.:runaround:

rum runner, did these things solve your issues?