Hard/Long start with hot engine, 87 4.0

[87MJJeep]

For quite some time, my 87 4.0 will fire up almost instantly when the engine is "overnight cold."  Nearly all hot or warm restarts require a long period of cranking (~8-12 seconds), and once it fires it runs really rough for several seconds.  It usually smells gassy.  Gently revving to 2K rpm and holding it there usually helps clear it up quickly.  

 

I have been driving it to work lately, and I was a bit surprised when after sitting since 8am, it would have the hard start at 2-4 pm.  Last night, I didn't park it inside.  I fired it up around 2pm with it "overnight cold," but it had sat in the sun all day.  This was the first time I had a hard start after it sat overnight.  

 

Is there any common issue that would cause long cranks to start when the engine is hot/warm or engine is technically cold, but it's been heated from sitting in the sun on a hot day?  

 

The gassy smell makes me think the issue is spark related since it's getting fuel.  Or are 84K mile original injectors flooding it when not cold?  

 

Any pointers are appreciated.  

[cruiser54]

Inspect this closely. 

[cruiser54]

Also, make sure your intake manifold bolts are snug.

 

Have you completed Tips 1 through 5 on my website?

[87MJJeep]

Hi Crusier,

 

I have not performed any of your tips yet.  :head held in shame:

 

I am headed to the store to get some CRC Contact Cleaner, OX-100B and carb cleaner ( for vacuum leak check).  

 

I have been following this thread:  

 

I'll check those bolts asap.  Bruce's comments on reaching some of the bolts already has me tensed up!  

 

Thank you!  I watched your C101 Elimination video last night.  I'll just do the cleaning for now.  

 

[cruiser54]

Bolts are easy with air cleaner removed. 

[87MJJeep]

1 hour ago, cruiser54 said:

Bolts are easy with air cleaner removed. 

Thanks.  I checked fuel pressure with just Key On (didn't want to start engine).  It went to 40 psi.  After about 20 minutes, the gauge was back to zero.  I didn't watch it over that period of time, so I don't know exactly how quickly it got back to zero.  When I removed the gauge, not a drop of fuel came out of the valve.  

 

Is the drop to 0 pressure in that approximate amount of time normal?