In need of advice

jeep
grand-cherokee

#1

Hi I’m new to this but here goes…
I have a 95 Jeep Grand Cherokee Limited 5.2l V8 318 an I was wondering if anyone knows why an or could tell me why my jeep would start bogging out going uphill at 70mph on the interstate??? Don’t matter if the gas tank is full of gas or close to being empty, it does it all the time after I get passed 65mph…

Anybody know how to fix this??? Any help or advice on how to fix this would be greatly appreciated, thanks


#2

That’s a maxiumum engine load condition, so you’re probably looking at some deficiency in the ability to deliver enough air or fuel into the engine. Or the ability of the engine & exhaust system to process it.

air filter, fuel filter, fuel pressure, fuel pump, plugged cat, ignition system, egr problems, compression.

I’d start w/any diagnostic codes stored in the computer memory.


#3

The problem might be with the Manifold Absolute Pressure sensor, or MAP sensor.

http://www.standardbrand.com/media/885939/ST10235AS-FEB14_JTF_MAP.pdf

Check out RockAuto.

Tester


#4

The very first thing that I would consider is…When was the fuel filter last replaced?
For reasons that I cannot fathom, that maintenance item seems to be ignored in many cases.


#5

GSJ’s ideas are logical. I would add that maybe the transmission is not downshifting. That could be a sensor or linkage issue, or something more serious.


#6

Go under your car with a rubber mallet, tap in the center of the bottom of the converter. If you hear rattling inside, the honeycomb is breaking up. Going uphill it can fall back and restrict the outlet.
All the other causes people mentioned are possible but this one you can check out yourself. If it is a restricted fuel issue, your car will run slower, the harder you step on the gas.


#7

Fuel filter, weak fuel pump, clogged converter, ignition timing not advancing for whatever reason, or a worn out engine.

If the fuel filter has never been changed (quite common) then I’d swap that and see what happens.


#8

I also get the smell of gas going down the road really badly too you guys know anything about that??? Well the guy who had it before me had an engine swap done on it, an the engine has about 44k on it…

But idk if that would effect anything…

I don’t have a cat converter on it…

I myself have not change the fuel filter so im probably going to try that this weekend…

Alright well going 70mph on flat road no problems, then going uphill at 70mph it bogs an slows down on its own even if I try to make it go faster or take my foot off the pedal then press it back down…

I don’t have the slightest clue when the fuel filter was changed, yea fuel filters are normally ignored in these cases an for some reason the fuel filter pops into my head every time I think about it…

An I didn’t think about the MAP sensor either an I’ll have to check out rockauto…

I went down to oreilly auto to have them do a diagnostic test on it an he couldn’t find the plugin for it an neither can I, it’s usually down by the gas an brakes pedal right???


#9

Do you notice any gas odor with the engine idling (engine warm) when you are standing near the tailpipe?


#10

When it’s idling/not moving, I do not get the odor of gas…
I only get the smell of gas when I’m going down the road when the engine is warm


#11

re: fuel odor. I think you’ve got a small fuel leak OP. It doesn’t take much of a leak at all to create a whole lot of gasoline odor. It’s probably just enough to evaporate into the air, not a liquid leak onto the ground. Does your jeep have multiple gas tanks, and a valve under the seat, etc, you switch between the two? If so, check there for a small gas leak. Since you smell it so strongly, it seems like it has to be either inside the passenger compartment, or in the engine compartment, where it could come into the passenger compartment through the air vents under the windshield .


#12

My Jeep does not have multiple gas tanks…
No valve under either seats…
How would my gas leak into my passenger compartment???
I smell gas through my dash vents an the vents up by the windshield…
I’ve never seen a Jeep with multiple gas tanks before lol…


#13

George . . . ?!

WTH . . . ?!

This is a Jeep Grand Cherokee, not an older Ford F-250 with the 7.5 liter big block and dual tanks

Neither have I . . . never even heard of such a thing :stuck_out_tongue:


#14

This is one year before OBDII, I believe the diagnostic connector is to the right of the engine near the A/C accumulator. It is an L shaped block connector, the zone people won’t have a scan tool to connect to this, the dealers DRB III and professional scan tools can be connected to this.

You can read fault codes by cycling the ignition from off to run 3 times, the third time leave the ignition in the run position and count the check engine light flashes, they are shown as two digit fault codes.