Hey guys, bit of a noob to full-size 4x4s here, although I've had an S-10 ZR2 previous to the K5.
Anyway, directly to the topic. Earlier this week, I bought a 1987 K5, something like 8" of suspension lift, TH350 conversion, with a bone-stock 350 with 87k on the clock under the hood. First few days of driving were fine, engine was a bit rough but I figured that was simply from working the kinks out - it hadn't been driven more than 5 times over the past year. However, yesterday and today, the engine's gotten very tempermental. It idles horribly when cold, where the rpms drop so low as to almost stall the truck out. When I come to a stop, the engine either typically nearly stalls, or cuts out completely. It also does this about 50% of the time when I put it in reverse. Four times now, the engine has cut out and won't restart (or stay running when I restart it) unless I pump the pedal when the engine is cranking, then stomp the gas as soon as it fires up.
Another known issue is a dead fuel sending unit, which isn't a big deal, as I was planning on replacing that along with the fuel pump in a few weeks. Since I don't know what kind of maintenance has been performed before I bought it, I'd prefer to take a proactive stance on fixing things, so I don't get stuck on the side of the road.
The biggest issue that's a concern to me is the oil pressure. It's fine when cold, and goes from 30-40psi when I'm driving (according to the LED gauge that's wired up, as the stock one in the dash is stuck and needs fixed). However, at low rpm, such as driving through town, or when sitting still, it occasionally dips as low as 8psi. I expect the pressure to be a bit low, since it is an older engine, but my Trans Am typically sits right at 40psi when idling. I know, different engine and all, but 8psi seems dangerously low to me. I know the gauge could be showing a faulty pressure, but it still worries me. I plan on having the engine rebuilt to make a bit more power in the future, but I don't want to have to do it before I want to, due to a spun bearing or anything.
I know I have an issue with the transfer case - the rear seal where the output shaft comes out is leaking and needs replaced, and the fluid coming out resembles gravy...I figure since it sat so long, some water condensed in the case and glopped the fluid up. It's going in the shop next week for ball joints, an alignment, and an inspection, and I'm going to have the case flushed, refilled, and the seal replaced then. I don't think this could be causing any problems with the engine, other than occasionally the truck will buck forward while stopped, but I've been attributing the engine nearly stalling out, then kicking back in while the truck is in drive.
I've got new plugs, wires, a cap, and rotor ready to go in this weekend, and I'll be getting a new alternator and battery shortly, just as preventative maintenance. My two biggest questions are this - what are some of the most likely culprits for the engine problems? I'm going to be cynical and not expect the parts I bought to fix anything, so I want to know what the best route to go with this would be. Fuel pump? Doesn't seem likely, since the truck idles fine 50% of the time, and is fine when driving - no bucking or anything like that. Sensors? I'm used to LSx engines, so I'm not sure what sort of sensor suite the TBI has on it, nor which one could cause issues like this. TPS? Other question is, how hard is it to install a new oil pump? That's definitely a high-priority for me, as I don't really like my engines to run with less than 25psi, minimum, at idle. I've got a garage full of tools, and have plenty of experience wrenching on my T/A, but i don't know how much of that will translate over to an SBC K5.
Sorry for the long post, just figured it'd be better to explain the entire situation in one post, instead of answering questions in a page of posts.
Anyway, directly to the topic. Earlier this week, I bought a 1987 K5, something like 8" of suspension lift, TH350 conversion, with a bone-stock 350 with 87k on the clock under the hood. First few days of driving were fine, engine was a bit rough but I figured that was simply from working the kinks out - it hadn't been driven more than 5 times over the past year. However, yesterday and today, the engine's gotten very tempermental. It idles horribly when cold, where the rpms drop so low as to almost stall the truck out. When I come to a stop, the engine either typically nearly stalls, or cuts out completely. It also does this about 50% of the time when I put it in reverse. Four times now, the engine has cut out and won't restart (or stay running when I restart it) unless I pump the pedal when the engine is cranking, then stomp the gas as soon as it fires up.
Another known issue is a dead fuel sending unit, which isn't a big deal, as I was planning on replacing that along with the fuel pump in a few weeks. Since I don't know what kind of maintenance has been performed before I bought it, I'd prefer to take a proactive stance on fixing things, so I don't get stuck on the side of the road.
The biggest issue that's a concern to me is the oil pressure. It's fine when cold, and goes from 30-40psi when I'm driving (according to the LED gauge that's wired up, as the stock one in the dash is stuck and needs fixed). However, at low rpm, such as driving through town, or when sitting still, it occasionally dips as low as 8psi. I expect the pressure to be a bit low, since it is an older engine, but my Trans Am typically sits right at 40psi when idling. I know, different engine and all, but 8psi seems dangerously low to me. I know the gauge could be showing a faulty pressure, but it still worries me. I plan on having the engine rebuilt to make a bit more power in the future, but I don't want to have to do it before I want to, due to a spun bearing or anything.
I know I have an issue with the transfer case - the rear seal where the output shaft comes out is leaking and needs replaced, and the fluid coming out resembles gravy...I figure since it sat so long, some water condensed in the case and glopped the fluid up. It's going in the shop next week for ball joints, an alignment, and an inspection, and I'm going to have the case flushed, refilled, and the seal replaced then. I don't think this could be causing any problems with the engine, other than occasionally the truck will buck forward while stopped, but I've been attributing the engine nearly stalling out, then kicking back in while the truck is in drive.
I've got new plugs, wires, a cap, and rotor ready to go in this weekend, and I'll be getting a new alternator and battery shortly, just as preventative maintenance. My two biggest questions are this - what are some of the most likely culprits for the engine problems? I'm going to be cynical and not expect the parts I bought to fix anything, so I want to know what the best route to go with this would be. Fuel pump? Doesn't seem likely, since the truck idles fine 50% of the time, and is fine when driving - no bucking or anything like that. Sensors? I'm used to LSx engines, so I'm not sure what sort of sensor suite the TBI has on it, nor which one could cause issues like this. TPS? Other question is, how hard is it to install a new oil pump? That's definitely a high-priority for me, as I don't really like my engines to run with less than 25psi, minimum, at idle. I've got a garage full of tools, and have plenty of experience wrenching on my T/A, but i don't know how much of that will translate over to an SBC K5.
Sorry for the long post, just figured it'd be better to explain the entire situation in one post, instead of answering questions in a page of posts.
