Bowman5115

So I have a 1984 toyota pickup I just replaced the fuel filter and fuel pump about a week ago. And the cat is about a year and a half old, sometimes when I try and start my truck it has a hard time starting.. does anyone know what this could be? I am thinking that maybe the cat is going bad because when I go up a incline it looses a lot of power

the_supernerd

Has it had a basic tune up (plugs, wires, cap, rotor)? Check the ignition timing as that could cause your problems. The choke can cause starting problems, especially when cold. A vacuum test will tell you if the exhaust is plugged. Vacuum will not rise as RPMs rise if you have an exhaust restriction.

user 82300

I really don't think your exhaust is clogged or how a vacuum test lets you know if your exhaust is clogged???

Start with simple things on your 22R
-examine all vacuum lines ESP ones on the choke.
-you can spray brake cleaner or propane around the base of the carb and around vacuum lines and IF the idle jumps you've located a vacuum leak so you can go from there.

There is a test to diagnose your choke.


P.s. A loss of power does not mean your cat is clogging...

Check your valve clearance, timing, also your distributor should have to vacuum lines coming off it. Inspect the vacuum advance assembly on the diStributor as well.

Your engine needs

Fuel
Air
And spark

Check the systems related to all three. A good factory service manual can be a huge help to learn and diagnose issues with your truck.

the_supernerd

Vaccum will be less as back pressure builds. The way I understand it, the exhaust cannot escape through a clogged exhaust, so the pressure builds up in the cylinders making it more difficult to build vacuum. There are some Youtube videos that will explain it much better than I can. On a related note, I doubt the original poster's exhaust is plugged. I had an S10 with an exhaust plugged so bad that it could not go over 25 MPH, but it would start, idle, and run at light throttle just fine.

Assuming both the starting problem and the problem climbing hills are related, then I would think tune-up or timing. It could easily be two separate problems, where I would need some more information to properly diagnose them. Do a tune-up, vacuum test, check the choke, etc.