THANK YOU EVERYONE!!! And I need HELP

[BROMAN]

Hello everyone.
It is my first time commenting. I just picked up a 1995 J30T with 160,000 miles a month ago. It was in decent shape and dealer maintained most of its life but was well due for some maintenance and repairs.
I first off want to Thank everyone who has contributed to these forums over the years. Within the last month I have probably saved a couple thousand dollars from DIY work that I was able to succesfully complete.
I did,
transmission fluid change, gasket and filter change
Oil change
Adjustable tension rods
inner and outer tie rods
all four brakes
rear shocks
plugs and air filter
cleaned throttle bodys
I am defenitly a backyard mechanic and learning as I go.
Anyway, the car runs great now and I only have plans to do the timing belt because I have no idea when if ever it has been done and that worries me.
The problem I am having is that when I am driving under a load more then just me. so either someone in passanger seat and or more people in back seat, that my car has problems accelerating. If it is just me in the car it will run like a bat out of hell, but as soon as someone is in that passanger seat sometimes its fine but it will be kinda jerky slow acceleration.
I dont have any idea what would be causing this because of the extra weight???
I heard knock sensors are common problems but would there be any reason it did this only under more weight?
I just did brakes so i was thinking somehow maybe the brake caliper is getting stuck while under weight but ive never heard of this.
I also think maybe transmission... I dont know im lost.
I dont have any CEL but im going to try and check for transmission or computer codes soon if I cant figure it out.
Any help would be greatly appreciated.

[Talamascan]

Do you hear any detonation with the extra passenger?

If so the ECU is "supposed" to retard timing and perhaps even shift to a richer "safety" map if it's bad enough, both of which will (of course) drastically affect power and drivability (with no CEL being activated). I used the word "supposed" because my car recently went through a major 3 week pinging experience and never once did the ECU seem to do anything whatsoever about it unless I physically disconnected the knock sensor, whereupon it ran like crap. BTW, the only way I could get the ECU out of the safety mode it obviously switched too when I did that was to reconnect the sensor and then disconnect the battary for a bit, something that does not fit with your symtoms.

[BROMAN]

No detonation!!
Its like a pinging or clicking sound right?
I dont hear any sounds when it happens just literally seems to loose acceleration and then kinda slowly gets up to speed and is a little jerky.
I dont think its the transmission either cause the rpms are flying high or anything before it kicks back in.
Im thinkin maybe even something like fuel filter. I know the pump has been done recently but dont know about filter. Would load have any affect on this?

[BROMAN]

Sorry meant to say rpms arent flying high before shifting. It seems to shift good.

[fourdrinie]

ok..here's a random thought...the ecu for your car is at the feet of the passenger....right hand side kick panel....suppose the connection to it is loose? that could be why the problem is intermittent and only happens when a passenger is sitting there possibly knocking his right foot against it....
Just a guess...
try removing the kickpanel, remove the ecu and reattach it firmly....
again...just a hunch

[Talamascan]

Yes, pinging sounds like a marble inside a can and you can also feel it through the gas pedal as a faint vibration.

This may sound stupidly simple, but rub a finger on the inside of the tail pipe. If it comes away black (and assuming you're not burning oil) then the car is running rich which will make it bog at heavy loads.

[BROMAN]

Hey guys.... Thanks for the help and info.
I went for a ride last night and it did it with just me in the car. It seems to do it when warm outside.
So since it is doing it with just me in the car now to i figured must be knock sensor as its same problem many others had.
This morning sure enough I pulled a 34 code so need to do the knock sensor.
Ill prob just do the relocation thing.
These cars def require some know how so these forums are amazing. Thanks again to everyone.