I have an '89 cherokee 4.0 with 190k on the dash.

I'm assuming the gas in the oil issue has been around. I had an issue with it starting and idling at 3k. Diagnosed the problem as being the I.A.C. valve. So it no longer does that.

But upon replacement found that the intake is oily. My thought is the rings. It does take some time to start. Almost as if the fuel is not staying where it needs to be on start up.

Any thoughts on if these are two different problems? Or can i kill 2 birds with one stone?

 

The gunk in the manifold is caked up crankcase fumes and is normal. It's not from gas. The injectors spray the gas directly into the head's intake ports. All that travels through the manifold is air and crankcase fumes. Looks bad but is no big deal.

Gas in oil is usually leaky injectors that bleed down after shut off or leak while driving. That could explain the loooong start, although the REnix is a 3 to 5 second delay before it starts anyway.

The Renix injectors had other issues also. The injector bodies would split and spray gas on the hot manifolds, sometimes resulting in engine bay fires.

For under $100 per set, replacement injectors can be had.

Tell us more about gas in the oil.....

 

The injectors from the outside are dry. Don't look damaged just old. I feel like a leaky injector is the problem but also lean toward bad rings

As far as the gas in the oil the dipstick smells like fuel more then oil. how many ways can fuel get in the oil besides going past the rings

 

Gas will get by good rings if the injectors leak.

 

(Just curious: how can you isolate a leaky injector?)

 

You mean just ONE?

 

Yeah, like trying to isolate a possible leaking one.

 

Good question....

 

Remove rail with injectors. Prime rail with fuel by turning key on. Shut key off. Watch for drips.

 

(thanks C)

 

Thanks. I'm definitely going to check that

 

Bare minimum, you need to fill your tank with gas, add a can of BG44K, run til 1/2 full, fill again and run til 1/8 tank. Fill with gas.

REALLY oughta do the upgraded injectors though....

 

Well written Pete. (in my opinion). A 3-4 inch slice of cardboard slid under the injectors can "reveal" their secrets.