My ignition switch locked up at about 133,000 miles.
At 138,000 the rear end started leaking.
The Master Cylinder for the brakes went out at 140,000 miles.
It uses a quart of oil every 1,500 miles.
The valves tick constantly.
The choke gets caught up in the winter time and will not idle correctly.
It uses excessive gas in the winter time.
This truck is very low on power.
The manual steering makes it rough on even the strongest of people.
The bucket seats are fairly nice. The interior in the extended cab has decent space.
The paint and body are in near perfect condition.
Peers at school rag me about how slow it gets up to speed.
I still like my truck.
I also own a 1989 Mazda B2200 (short bed/regular cab). I've had it since 1992.
The oil consumption could be due to oil leaking past the front cam bearing cap. This is located just behind the plastic cover for the timing belt at the front of the engine (the distributor plugs into this cap). It is exposed (i.e., not under the valve cover) and the only seal is the metal-to-metal fit of the cap to the top of the cylinder head. Mine has always leaked. The factory manual says to seal it by applying Permatex sealant to the mating surface of the cap. I did this when I rebuilt the engine and it worked, but only for a short time. Eventually the leak came back and I've simply lived with it ever since.
The ticking valves indicate the need for either an adjustment of the mechanical lifters or replacement of the hydraulic lifters, whichever your truck has (I understand that Mazda offered both during that year, meaning they may have changed the style of cam lifter used for that engine DURING this particular model year).
If the valves are mechanical they will tick upon initial startup. This is caused by the clearance between the lifter and the top of the valve. As the engine warms up, the metal heats up and expands, closing the clearance and eliminating the tick.
Hydraulic lifters don't require this clearance, since they basically act as a minature shock absorber and should always be in contact with the top of the valve.
If the tick is always heard (especially at idle) then either the clearance is too great (mechanical) or the rubber seals inside the lifter (hydraulic) have worn away and they are no longer working properly.
The only cure, in the case of the hydraulic lifter, is to replace them.
The reason the lifters may become worn is either (at the time of this writing - 11/12/04) time, if their original, and/or lack of oil pressure, which would starve them of proper lubrication and wear them out prematurely.
The lack of oil pressure is caused, directly, by the oil pump, which is located at the bottom of the engine, in the very front (the front snout of the crankshaft actually goes through the oil pump, driving it). The oil pump is a gear driven affair and contained within an ALUMINUM housing. The oil pressure regulator is also contained within the house and works via a STEEL piston that works against a spring. As oil enters the pump it goes through a passage that contains the regulator and pushes against the piston. The passage has two small holes. One directs the oil to the rest of the engine, the other is a drain that puts some of the oil back into the pan. This second hole is uncovered (as the piston slides far enough in the passage to expose it) when oil pressure exceeds the limit warranted by the manufacturer (33psi, in this case). This is how the pressure is regulated. The problem here is the STEEL piston has VERY sharp edge and as it slides in the ALUMINUM housing it wears away at the passage, eventually causing enough clearance that the piston cocks and gets stuck in the passage. This exposes both holes and keeps the oil from staying at its proper pressure, especially at lower RPM (like idle).
The only cure in this case is also, replacement of the oil pump.
Premature wear of the pump (and more importantly, the pressure regulator) can be caused by a low amount of oil in the sump (pan), which could be caused (at least in part) by the leak at the front camshaft bearing cap.
You can prevent premature wear of the pump by keeping a close eye on the oil level (and it sounds like you're doing that already).
However, at this point, it looks like a new oil pump and (possibly) new lifters are the only cures for your valve ticking problem.
Low power could be caused by the carburetor constantly running through the high idle circuit.
The carb's choke was designed to run the engine at very high speeds (approx. 6000 RPM) for a very short time (about 30 seconds), to facilitate quick engine warm-up at initial start-up (this is a "low emission" thing that was done on purpose). If you've readjusted the high idle to what most would consider a more "normal" speed (say, around 1600 RPM), then you've thrown the choke setting so out of "whack" that the truck is constantly running through the high idle circuit.
The choke needs to be readjusted (.063" clearance between the boss on the body of the carb and the lever which works the choke) and whatever the carb's problem was in the first place properly diagnosed, or you could...
A) Remove the choke plates (at the top of the carb) and continue the run the carb in it's present state.
B) Change the choke to a "manual" affair, leaving the high idle where it's at and you control the amount of choke via a lever or button from the cab.
C) Replace the carburetor altogether with a different make/model.
...Personally, I chose "A" because it was the easiest fix and I didn't have a lot of time, or money, on my hands at that particular time.
I immediately noticed a raise in fuel economy (went from 22 MPG to around 25 MPG) and the truck became more powerful.
...I also replace the air filter at that time, as it was clogged and cleaning it did not help.
In the future (depending on how much longer I own this truck, and I've had it for about 12 years now) I do plan on replacing the carb with a different make/model (possibly a pre-emission GM 1-bbl), probably with a hand choke.
Hope that cleared a few things up for you.
Please feel free to write me, if you have questions concerning what I've written here - gundorps@yahoo.com.
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