Well I liked the way it drove and it did not seem to need anything like brakes, tires, transmission (manual with firm clutch) so I went ahead and picked it up for $1100 even though the 98 S10 4.3L is showing 524K miles as a project truck.
It is so much like the 2002 Blazer and I have the factory manuals for it which should be good info for a lot of the same systems in the 1998 S10.
The truck had not been driven in a month the guy said but I would guess it could have been several months because it was parked in a shed over at his mom's place.
Coming home in it I noticed it would miss if I got on it hard running down the road like going from 30 to 50 mph in 3rd gear (still under 3K RPM) and it would keep missing for maybe a half mile then smooth out again.
After driving it about 60 miles in 20 mile runs me and my son hooked the scanner to it and drove it some. The miss would return then go away. Then I got on it harder (no red lining stuff but more like some take offs like the 2002 Blazer does over and over without issue we got it to pop PO305 that then turned into a PO300 multi cylinder miss that no longer goes away. The MAF PO101 over time will reset after cleared.
Well the idle is rough now yet it is still quite perky considering.
The PO300 code has a 1000 possible causes.
A code P0300 may mean that one or more of the following has happened:
Faulty spark plugs or wires
Faulty coil (pack)
Faulty oxygen sensor(s)
Faulty fuel injector(s)
Burned exhaust valve
Faulty catalytic converter(s)
Stuck/blocked EGR valve / passages
Faulty camshaft position sensor
Defective computer
Well my project truck is going to be that for sure but it is still worth $400 at the scrap yard.
One plus has been to appreciate the 2002 Blazer with only 192K miles when we drove it tonight knowing it may not be half way worn out yet.
If I can get the 1998 5 speed running well I will drive it a lot and practice on the project truck so when the 2002 needs deep service I will have been there and down that. Plus with two trucks with a lot if interchangable parts it will make swapping parts to trouble shoot easier. If a part off of the 2002 fixes the 1998 I will just put the new part on the 2002.
Short of being a burnt valve or maybe the computer which may not exchange with the 2002 most of the other possible causes listed above are normally replaced items anyway.
Since the is no knocking, decrease in oil PSI, mixing of fluids and still good power even with the PO300 miss I hope I just pushed the miss that was there from time to time into a full time problem that is addressable without a lot of cash.
Before the PO300 occurred an oil change was about the one real need it had as far as I can tell so I am hopeful at this point. If it does not work out I may keep it for spare parts for a while then sell for scrap. Buy-in price less scrap value is just $700. I have had more expense projects as in the MH.
Oh I was going to mention have been running a heavy Sea Foam mix on leaving the seller's place and think that may have loosen some junk in the fuel system perhaps.
There is strong spark from the distributor on all six cylinders so that leaves the wires and plugs to check out. It will start and run with all the plug wires disconnected at the same time on either left/right bank. The only wires that will decrease/increase idle speed (yes it will idle but with a lope) is the middle wire on each bank at the distributor connection?
