I have a 91 S83P that I can not get to start. It's a recent purchase and when I bought it I was told it did run but the carburetor needed replaced. The new carb came with the truck he just never put it on. I have replaced the carb and put new fuel lines on and have confirmed I have gas going to carb and all 3 plugs do have good spark. I then checked the timing and have the timing marks lined up with #1 tdc and the right stroke. I have even taken the distributor cap off and the rotor was facing the #1 wire. I've gave it some gas and starting fluid and still can't even get it to hit. I took the value cover off and everything looks good and clean and all the valves are moving when I turn it over. There is no oil in the radiator when I drained it and also checked out pan and no antifreeze in the oil. I did go get a compression tester and I don't get any compression on all three. I find that a little odd that none of the register, but full disclosure I'm not a mechanic and don't claim it. I did take a camera and looked in all 3 cylinders and everything looks good in them, piston heads other then a blacken but normal from what I seen other pistons look. The cylinder walls all look clean and don't see any marks or scratches. I would add that I put a brand new battery on it and keep a battery charger on tinder to that battery but to me when I try starting it seems sluggish. It won't turn over more then 30 seconds or so and the battery seems to be almost dead, even with battery charger on and switch to start. I can turn the motor with a wrench and it's not catching or seems walk hard to turn. Would this cause issues with it starting or low compression. I tried attaching video of ot turning over so someone could determine if that sounds norI looked through several other threads and they have helped me get to the point I'm at, but seem stuck now. Any thoughts or something new to try would be greatly appreciated.
I need to add that when I got truck distributor adjustment bolt was loose. I put it in the middle of the range of adjustment and tightened it back down. It looks like that was where it was at originally but no way of knowing for sure.
Sounds like you may have some bent / stuck valves - serious, but not the end of the world. Remove the valve cover, and watch the valve action as you rotate the engine by hand. All valves should open and close fully. If some stay partially open - indicated by very loose followers ( large clearance ) then you will have found the problem. Or you may find something else. But it is at least a starting point and costs nothing but your time. Good Luck
I did find a couple of problems that solved some issues. I had the cover off already and has I was rotating the motor by hand I did notice that none of the intake lifters ever got any slack in them at all, they always had tension on them. I went through and put all of them at Tdc and loosened them all just so they barely had some slack. After doing that I did a compression test again and all of them had good compression. Was able to turn it over and it did finally actually start. It ran rough but I'm guessing that is in the carburetor adjustments. I'll start there next after I get everything back together. I would not that when I took the value cover it doesn't look like it has ever been off so not sure why all three we're set like that. My next thing is does anyone have the correct gap that the lifters need to be set at. I've seen a couple different things and they need to be hot in order to adjust but not real clear on the correct gap. As far as the weak starter I've all but determined that was a bad ground. I connected the ground clamp from the battery charger straight to engine and it worked fine. I replaced the neg battery cable and took wire wheel and cleaned the wire connections from the frame to motor and that's fixed thr problem there.
good progress, congrats. I cannot find in the forum or online a workshop manual for your engine, maybe you buy one online for the S83P. Also add your cat details as a signature, see for example my one, then it is always shown in all of your posts and we do not have to ask for the car details. G & R Imports has the manual for sale https://www.grimports.com/
Sounds like you have it under control - like you said, the valves have probably never been adjusted since new. Normal wear on the valve heads and seats eventually eats up the clearance. Hopefully there is no serious damage, and your compression test indicates that things are probably OK. Valve clearance is listed a. 0.098 inch ( 0.25 mm ) on the intake and 0.0118 inch ( 0.30 mm ) when the engine is hot. If adjusting cold, I would set them a bit larger at 0.011 inch on the intake and 0.014 inch on the exhaust. You may notice a bit of valve clatter on initial cold start, but it goes away quickly as the engine warms up and the valves expand.
Thank you very much, that is what i was looking for. I'll work on that this week. Now another question, I've read several places on here about checking the timing and it seems most everyone is running at 7 degrees at 1000 rims. This could be a really stupid question but the truck doesn't have a rpm qauge. What's the best way to check that I'm at 1000. It might be just fine but when I start trying to figure out adjustments on carb I feel like I better check the timing before I put bed back on and start down the road with it. I really do appreciate all the input so far. Like I said a mechanic I am not, but I've been working through it so far.
You need an external gauge to tell you the rpms. The reason they have you do it at 1000 rpms is that if the rpms are much higher then the vacuum and mechanical advance kicks in and messes with the timing. I got a DVM at Harbor Freight that also has a function to tell you the rpms. It even has a 3 cyl setting to make it easier. Lately I have been using that for my van because my old Suntune gauge only does 4 6 8 cylinders and it was hard to read for a 3 cyl. I was going to post a link but they don't sell it any more. I found it on ebay https://www.ebay.com/p/655679641. Amazed you can't get em anymore, I got this in 2021, so only 4 years ago, if that. Oh well.
Solved a few other issues but a few more has popped up. I did use the clearance values that was listed and they is no more noise coming from valve cover so those must have been the right ones. I've got the timing set now. It will rarely start up with just a shot of starting fluid, but once it's running and warmed up it will set and idle for as long as you let it. I've adjusted this carburetor until I'm blue in the face and felt like I have it pretty good except the small screw behind the idle screw just doesn't seem to do much, maybe idle it up just a little or chock it down a little but nothing dramatic. I've driven it around my house and it seems to be driving fine. I can pull it back in the barn and shut it off and try to start right back up and it won't start unless you give it a little shot of either. Does this sound like I've got an adjustment wrong or something else.
Do you wait a few seconds for t he pump to fill the bowls? Try keying it on and counting to 10 or 20 and then crank it. See what happens. I also wonder if the carb is siphoning fuel into the engine when its turned off and causing a flooding situation.
Solved another issue and some might find helpful. The issue with it not starting right back up i believe i have solved now. I have always had an issue with what I thought was a weak start as I mentioned early on in my post. It would start and you could try starting it back up but the battery was going dead. Which seemed To quick to die with it being a new battery. I put my boat battery on the truck and would get the same results. I know i had good grounds as I already fixed those. I was going to unplug the wire harness and clean those. When I went to unplug one I bumped the starter with my wrist and it was smoking hot, like you couldn't touch it. I searched online and found this starter on Amazon. https://a.co/d/dpuEsjc I chose this option because I didn't want to wait for someone to look at or rebuild the starter. It arrived today and it look very similar to the original except when I went to put it in it would not fit tight. I tried starting it anyway and I couldn't believe the difference it made turning it over, however when it did start it was apparent the starter didn't disengage. After some trial and error I shimmed the starter with three washers. It doesn't fit tight and I'm going to have to put a little sealant around it to keep water from splashing in, but it just a small crack. I know not the best, but I'm OK with it. Now it fired up with just a few cranks. I let it warm up and shut it off and started it right back up ever single time at least a dozen times and the battery never seemed like it was weak or anything. It made a world of difference. I will add I'm still fighting getting the carb adjusted just right. I had to pump the accelerator once ever time I tried to start it back up but one pump and it was going. It also just seems like it missing a little bit when it's running. When you hit the accelerator it will ref up and it goes back down to idle very slowly. I'm still messing with it, but it's a huge relief that when it dies I'm able to fire it right back up now.
I sent my alternator to Precision Power in Lansing Michigan. They are willing and able to repair most anything. Use them if you want the original rebuilt.
