89 4.3 questions

[S10newbie]

About 3 months ago I bought my 89 S10 as a work truck. I really like this truck and now I want to fix it up a bit (my wife thinks I'm crazy). I've noticed a few things/issues with it and was wondering if anyone might know what to check for. BTW, it's a 4.3 automatic with AC, about 95K miles and doesn't look like it was well maintained since it was this other guys work truck. Anyway, here goes.
1) Sometimes it runs really great, lot of power, etc. Other times, it seems to surge/hesitate throughout the driving range and poor idle. At idle, It'll stumble, something under the hood 'clicks' and the idle picks up then after a bit it 'clicks' again and back to the stumble. I've changed the plugs, rotor, dist cap, wires and air filter but haven't done the fuel filter yet.
2) After driving for about an hour or so, I noticed water from the AC unit dripping. It's clear so I know it's not the cooling system. Condensation? But why, the AC is not turned on. This may be related but after restarting, the windows begin to fog up near the dash vents without the fan on.
3) Is it possible to install speakers in the door vents? If so, what size? I haven't pulled the door panels yet to have a look.

Any help or advice is GREATLY appreciated. This is a fantastic site!

[OverBoardProject]

The first thing that I like to change on fuel injected auto's is the fuel filter, just because most people don't change them often enough which kills the fuel filter (very expensive job to replace) Anf a full tune up will probably fix your motor problems.

Most auto's with air conditioning use the air to defrost the windows, which is probably why your AC unit is dripping. If you can just turn the heat (or vents) on and leave the defrost off and see if the system still drips then.

Your door vents are there to help the doors close, and to help any moisture dry, so you really shouldn't plug them up with speakers.
Any welder will probably plasma cut speaker holes into your doors for a very low price. It's only a 10 in job if you pull the door panel for them, and mark the holes oul

[OverBoardProject]

Oh that's kills the fuel pump, which requires you to either raise the box, or lower the fuel tank.

[jackass#1]

the clicking noise you hear is the ac unit. it does come on when you use your heat. i bet when you change your fuel filter it might clear up a bit. if your old fuel filter seems really full of crap, after you put the new one on check you fuel pressure to be sure you pump is fine.
if you have a tbi pressure should be 9 to 14 psi.
hope that helps.

[Mikado14]

Originally Posted by jackass#1

the clicking noise you hear is the ac unit. it does come on when you use your heat. i bet when you change your fuel filter it might clear up a bit. if your old fuel filter seems really full of crap, after you put the new one on check you fuel pressure to be sure you pump is fine.
if you have a tbi pressure should be 9 to 14 psi.
hope that helps.

On an '89, the AC will only run in the Defrost mode, not the heat or on the vent position.

[jackass#1]

you sure my 91 does?

[Mikado14]

Originally Posted by jackass#1

you sure my 91 does?

If your '91 has the same heater controller on the right side of the instrument panel as a '94, '93', '92, '90, '89, etc.. The A/C should run in the A/C, Bi-level, Max and defrost positions. It should not run in the vent or heat positions.

[Mikado14]

Originally Posted by jackass#1

the clicking noise you hear is the ac unit. it does come on when you use your heat. i bet when you change your fuel filter it might clear up a bit. if your old fuel filter seems really full of crap, after you put the new one on check you fuel pressure to be sure you pump is fine.
if you have a tbi pressure should be 9 to 14 psi.
hope that helps.

A serious question. How will changing the fuel filter clear up an A/C problem? Am I reading your answer wrongly?

[OverBoardProject]

Originally Posted by Mikado14

A serious question. How will changing the fuel filter clear up an A/C problem? Am I reading your answer wrongly?

No changing the fuel filter won't correct a air conditioning problem but it will help your truck run better, plus help save your fuel pump.

I don't think that there is any thing wrong with your air conditioning, except it might need a good service in the spring. To me it sounds It's acting normal.

[jackass#1]

youre right my ac doesnt come on in those positions, just used to running defrost all the time and i got confused. lol
yes you read it wrong, i should of started a new paragraph when i started on the fuel filter.
sorry about the ac thing. and i promise never to have run on sentences ever again. lol

[vtmecheng]

S10newbie: If you are noticing the power loss problem, related to the click noise, with AC or Defrost on then the most you can do is have the compressor and AC system looked at. If this problem is occuring with the heat/vent on or when nothing is turned on then you have a problem. That means your compressor is turning on when it isn't supposed to. In this case something in the electrical is shorted out and should be diagnosed. Good luck.

[Mikado14]

Originally Posted by OverBoardProject

No changing the fuel filter won't correct a air conditioning problem but it will help your truck run better, plus help save your fuel pump.

I don't think that there is any thing wrong with your air conditioning, except it might need a good service in the spring. To me it sounds It's acting normal.

UH,,, Overboard, I didn't ask the original question and was only asking jackass#1 what his reasonning was for changing the fuel filter for an A/C problem which he has answered.

[jackass#1]

s10newbie, are you there? could you reply to any of this? hows it going?

[S10newbie]

Originally Posted by jackass#1

s10newbie, are you there? could you reply to any of this? hows it going?

Yeah, I'm still here. Just been working a lot of 10-12 hour days this week and I haven't had the energy to 'play' around with the truck.

Regarding the AC clicking, I do run the defrost mode most of the time but I'll try and mess around with the controls and see what happens.

Hopefully, I can 'play' this weekend a little bit. I'm planning on changing the fuel and air filters, PVC valve (seems OK, but cheap to replace) and was thinking of checking/cleaning the EGR since I've seen other threads mention this. Thanks all for the suggestions. I'll update when I have something.

[jackass#1]

yeah the egr is a common problem. as for the water dripping from ac unit, its normal if the ac unit is in operation. as mentioned earlier ac unit does come on
when you use your defrost.
let us know how things go.