1992 Nissan Pathfinder 4X4 power issue

I am trying to figure out why a 1992 nissan pathfinder will not pull itself up a
small hill/out of drivewasy. It is an automatic 4wd. The engine runs fine in
park and neutral. place the shifter in drive or reverse and the engine spitters
and sputters. Have replaced spark plugs, distributer cap, rotor button, oil,
oil filter, transmission filter and fluid, air flow meter, air filter, had coil
tested, and fuel filter. I noticed today that with the transmission in reverse
or drive that the brake pedal was hard as a rock and barley moved as the engine
sputtered around 1,500 rpm. When i revved the engine and was able to get it
around 3,000 rpm the brake pedal moved down to the floor like it does in park.
One of the exhaust manifold bolts broke last year and has yet to be fixed.
Transmission was rebuilt 2 years ago. Am i fighting a vacuum leak somewhere?
Is the torque convertor gone bad? Any thoughts or ideas would be greatly
appreciated.
Spedracr

89 LX 5.0 5Sp Conv. Stock for now.

Spedracr wrote:
> I am trying to figure out why a 1992 nissan pathfinder will not pull itself up a
> small hill/out of drivewasy. It is an automatic 4wd. The engine runs fine in
> park and neutral. place the shifter in drive or reverse and the engine spitters
> and sputters. Have replaced spark plugs, distributer cap, rotor button, oil,
> oil filter, transmission filter and fluid, air flow meter, air filter, had coil
> tested, and fuel filter. I noticed today that with the transmission in reverse
> or drive that the brake pedal was hard as a rock and barley moved as the engine
> sputtered around 1,500 rpm. When i revved the engine and was able to get it
> around 3,000 rpm the brake pedal moved down to the floor like it does in park.
> One of the exhaust manifold bolts broke last year and has yet to be fixed.
> Transmission was rebuilt 2 years ago. Am i fighting a vacuum leak somewhere?
> Is the torque convertor gone bad? Any thoughts or ideas would be greatly
> appreciated.
> Spedracr
>
> 89 LX 5.0 5Sp Conv. Stock for now.
You may have a vacuum leak. Try plugging up the hose to the brake vacuum
booster.

Ok,

I plugged up the line going from the brake vacuum booster at the point where it
entered the intake manifold and the vehicle barely made it halfway up the
driveway. This is an inprovement but still not drivable.

After reconnecting the hose with the vehicle in park i could but the gas to the
floor and count to 5 before it starting increasing the engine rpms.

Is it possible that the leaking exhaust valves has managed to burn a hole in the
intake vaulted and now it is not making the correct compression/vacuum?


Rob Munach <[email protected]> wrote:

>Spedracr wrote:
>> I am trying to figure out why a 1992 nissan pathfinder will not pull itself up a
>> small hill/out of drivewasy. It is an automatic 4wd. The engine runs fine in
>> park and neutral. place the shifter in drive or reverse and the engine spitters
>> and sputters. Have replaced spark plugs, distributer cap, rotor button, oil,
>> oil filter, transmission filter and fluid, air flow meter, air filter, had coil
>> tested, and fuel filter. I noticed today that with the transmission in reverse
>> or drive that the brake pedal was hard as a rock and barley moved as the engine
>> sputtered around 1,500 rpm. When i revved the engine and was able to get it
>> around 3,000 rpm the brake pedal moved down to the floor like it does in park.
>> One of the exhaust manifold bolts broke last year and has yet to be fixed.
>> Transmission was rebuilt 2 years ago. Am i fighting a vacuum leak somewhere?
>> Is the torque convertor gone bad? Any thoughts or ideas would be greatly
>> appreciated.
>> Spedracr
>>
>> 89 LX 5.0 5Sp Conv. Stock for now.
>You may have a vacuum leak. Try plugging up the hose to the brake vacuum
>booster.

Spedracr

89 LX 5.0 5Sp Conv. Stock for now.