TheAngryViking

'94 GC 5.2 AT AWD 180,000 "but it's got nice tires..."

I have stalling on deceleration, right around 1500rpm the revs just drop, sometimes stalling sometimes bouncing back up to 750rpm with a rough idle. And, when I give it a tiny bit of gas in reverse, it stalls out.
Plenty of power on kick down, forward and rev.

When on the road, at 1300--1600rpm she runs like poo, all rough and surgeish (is that a word?).

Oh, and it's got a real oily smell to the exhaust, no blue smoke, sort of a gray vapor coming out the pipe. The amount of smoke does not change much when rpms raise or under a load.

Is it the TPS, MPS, O2, IAS, PCM? Vacuum sucks well, cleaned up the TB.

Oh, and all this stuff varies nearly every time I start it.

Jeepman659

is it throwing codes? and have you checked the spark plugs to see which ones f in up? you'll see abnormal amounts of black residue or oil on it if somethings going pretty bad in that cylinder.

TheAngryViking

The only dash light code it puts out is the code for no codes.
Checking the plugs now.

Bustedback

Those engines have a plate on the under side of the intake manifold, sometimes the gasket for that plate will kind of blow out and cause vacuum leaks (running like poo) and suck engine oil into the intake (oil smell at the exhaust). The only way to confirm this is to remove the intake manifold and take a look. When re-installing the manifold, be careful not to over torque the bolts, it can crack the block at the cam bore webbing. I think the spec is only 12ftlbs. Hope this helps.

Jeepman659

alright man i'll try and pay attention to your thread to help out.

TheAngryViking

Motor is a bit hot to pull the plugs, I know I'll bust a knuckle or two today, don't want to burn one too.

I've heard about the plenum gasket issue before. Pulling the intake is the last thing I want to do, unless it's not as tough a job as I imagine.

"...honey, warm up the credit card".

Jeepman659

the only real "hard part about it is you might ruin the gaskets by taking it off and the exhaust and intake share common bolts so that part really sucks you have to take off the exhaust too.

Bustedback

He's got the 5.2 V8, not the 4.0. The hardest part is removing the distributor and making sure the NEW intake gaskets stay seated when installing the manifold.

Jeepman659

my bad haha i missed that part. sorry dude.

TheAngryViking

My hunch is, I need to do a compression check before I go yanking distributors 'n stuff.

There's a Jeep place nearby Olympic 4x4, they offer a used engine with 140# compression, installed for around $1500. Good deal?