Vacuum leak

[f6john]

for the last two years the square has sat a lot. It has never been a good smooth running truck since I’ve had it, going on 8 years now, but I haven’t invested much time in it either. Recently I’ve have the need to use it a little and the first thing was to get the dragging front brakes repaired. Got that checked off the list this past weekend. Test drive proved disappointing but it ran, raised the hood and fortunately the hissing was loud enough I could hear it over all the other running noises even with my poor hearing. Sure enough the vaccine hose coming off the front of the carb base was hard as a rock and split around the Pcv nipple. A new piece of hose and it’s running so much better.

Wish I was better at diagnosing problems.

 

[Snoots]

Sounds like you did good here. I'll bet there a lot of other hoses that need replacing too.

 

[1987 GMC Jimmy]

I'd say that's a safe bet. I'd be putting the vac gauge on it to see how far you are from ideal.

 

[paulrowe]

What would be the ideal vaccum you would be looking for?

 

[Obwonkonobe]

What would be the ideal vaccum you would be looking for?

For stock, anything close to 20 is fine, just as long as it dosn't shake too bad

 

[1987 GMC Jimmy]

Yeah, I'd say with a stock cam you want 17 or higher.

 

[Camar068]

I put a vacuum gauge in front of the carb on mine. Made troubleshooting really quick in regards to vacuum. Made a little bracket to hold the gauge and tee'd into a vacuum line.

If I see it it drift I pull out the starter fluid and start spraying vacuum hoses and such until the idle changes.

 

[f6john]

I’ll hav to give it a try soon, there is still room for improvement I’m sure.