Some of you know I have an old junker that I use to do the dirty work around the house. It's a 1989 Nissan hardbody. Great little truck that is tough as nails. However it's been giving me issues lately with idling and running right. It will fire right up and idle at first but in a few seconds it will start skipping and sputtering quite badly. I talked with a few people and it was suggested to check the brake booster since I said I have crappy mushy brakes. It is not leaking and I replaced the booster and lines with new parts off a known good truck that was totalled. Then fuel pump was mention but I haven't touched it yet. Many of the lines in it are dry rotted so I think I have a major vac leak. Reason I say this is when you remove the top of the intake, if I cover the throttle body with my hand it'll idle and run PERFECT. AHA am I getting too much air? So I want to eliminate all the vac lines if I can. What is involved with doing such? I'm thinking I only need the PCV line, the brake booster line, and the vac line that goes to the fuel regulator. Can I simply cap off all the others to see if that fixes my issue?
It kind of makes sense that it is getting too much air if your pump is weak or a filter is clogged. That's why it runs better if you cut air off to the motor. Your throttle body could need a good cleaning as well how many miles does it have?