Low oil psi and some start-up issues

[cdmcfarland]

Alright, round two of CJ issues. After solving my gasket disaster, I've noticed recently that the oil pressure has dropped down significantly from where it was about a month ago. At idle, it barely sits above 0, and at highway speeds of 60-65 it's not even reaching 40psi.

There also appears to be some oil leaking from below the Jeep now, just a few drops when I park, but I think it's from a pretty chewed up seal (or gasket, not sure which it is). There's no oil leaking from under the hood, aside from whatever I didn't wash off from the last mishap.

Anyway, I'm not sure exactly what it could be. It's a long-shot to replace the oil pump if I don't have too (seeing as they're $130+).

I wouldn't be overly concerned but if I'm going highway speeds and have to stop semi-fast, i.e. pulling off an exit ramp to a stop sign, it will occasionally just stall out completely. I'm fairly certain it needs new spark plugs and wires (get an occasional rough idle), but I don't think that would effect the oil pressure? No idea though - I'm no car wiz.

Second set of problems is the start-up. I began to think it needed a new starter, but it's pretty sporadic, so I'm not sure. Anyway - to start it up after sitting for a day or so, the previous owner told me to push the pedal to the floor once, turn the ignition, and it chokes until I put it into gear and move. This worked great until I started noticing the difficulty in getting it to fire up after sitting for 30mins - 2 hours. It's still hot (engine is around AMC 150 most of the time) but it won't fire up without stalling out after a few seconds or without keeping the key turned until it starts. The pedal (which I'm assuming is connected to the choke somehow, as it SHOULD have an electric choke, but doesn't appear to work very well or at all) trick doesn't seem to work at all in this situation either. So, I'm clueless and don't feel like taking it to the shop to have them find out for a handsome fee unless it's a last resort.

Needless to say, need some serious help! Thanks in advance!

 

[IOPort51]

Oil pressure" what I think I know.

it may be a problem with a worn out pump or it could just as easily be worn out bearings or a broken push rod will also do this. believe it or not a broken push rod can be rather difficult to detect. It could also be a problem with the connection of the wire on the sending unit. I went through this once where the oil pressure would drop slowly as the engine warmed until I had 5 or 6 PSI at highway speed. mashed the connector with pliers and problem solved.

question: do the lifters clatter when you are at idle?? I have been told that 3 to 5 psi will keep a motor alive for a loooooong time. I have seen old trucks with barely measurable pressure go on to be drive for another 100K. I am not saying that you do not have a problem, low/no oil pressure is not a good thing but if you have enough pressure to keep the lifters pumped up it may be time to put a mechanical gauge on it and confirm your suspicions.

I am also guessing you have no idea how many miles are on this engine?

I will let someone else have the pleasure of discussing the problem of stalling. just one question: do you still have the original carter 1 bbl carb??

 

[cdmcfarland]

Heyo, thanks for the response! It has 119,900 miles on the engine. And as for the carburetor, no clue! I'm fairly certain the electric choke doesn't work though, as by pushing the pedal down and watching the choke it doesn't flip or move at all.

I'll take a look at your suggestions though and see if I can figure it out! I'm planning on dumping money into a AMC 258 i6 / 4.2l rebuild at some point, just hoping that it's not too soon. So many things to fix and so little time... and money!

 

[cdmcfarland]

Oh yeah, quick side note. It apparently keeps normal pressure when the engine isn't hot. Just went out and fired it up, and it sat at 10-20 psi in idle and as I drove it around the block a few times it stayed between 40-60 psi. So, the pressure seems to drop when the engine is hot - not cool. No idea if that helps the situation at all but what the hell. When it's hot and in idle, you can hear a pretty distinct ticking noise from the engine, which may the lifters.

 

[mtnwhlr]

Mine had low pressure at idle so I put a mechanical guage in and it still reads about 5-10 at idle when hot but goes to about 50 driving has been that way for a long time with no problems. As for your carb my choke has not worked for a long time and I get by just fine. You should look into doing the Nutter Bypass then you will not have the computer messing with your settings on the carb and timming.

 

[IOPort51]

You think he still has a computer on the AMC 232 i6 ??

We need some pictures of the engine, carb and distributor.

 

[cdmcfarland]

Well I'm going to order a mechanical gauge regardless now seeing as that's the popular consensus. Also, here's some pics of the engine/carb/distributor. They're huge so I'll just give you the link to imgur and you can check them out that way, unless you want me to post them here!

Engine/Carb/Dist - Imgur

 

[mtnwhlr]

You think he still has a computer on the AMC 232 i6 ?? .

you are right I didn't see what year he has forget what I said about the Nutter Bypass

 

[cdmcfarland]

The bypass is for 83 and up, isn't it?

 

[mtnwhlr]

Yes I think you are right. His does not have the computer.

 

[cdmcfarland]

Is it possible that the carburetor is about shot? I don't think it'd be a starter, as it doesn't have the grinding, fast-clicking noises when I turn the key.

Seems like it just takes a few seconds for something to kick on to fire it up. Yet if it's a complete cold start, it'll fire right up after pushing the pedal down once and letting it choke. It likes to do it at random times, sometimes after being ran for 10 minutes and sometimes after being ran for 3 hours. More of an annoyance issue really, until it just doesn't start.

 

[mtnwhlr]

It just might need a good tune-up.

 

[cdmcfarland]

Probably be smarter to start there, eh? Lol.

I just always assume the worst - this damn things been a trip and a half so far. Any recommended mechanical oil pressure gauges? I know JC Whitney has the AutoMeter ones: AutoMeter Products Autometer Autogage Universal Oil Pressure Gauge - JCWhitney

Not sure if they're any cheaper or not anywhere else, just trying to get a good sense of which brand to go for. Assuming that 10 dollar Equus gauges wouldn't be much better than my 30 year old one that's in there already.

 

[IOPort51]

always keep in mind that it is just a machine and is not capable of consciously pissing you off.

Probably be smarter to start there, eh? Lol.

I just always assume the worst - this damn things been a trip and a half so far. Any recommended mechanical oil pressure gauges? I know JC Whitney has the AutoMeter ones: AutoMeter Products Autometer Autogage Universal Oil Pressure Gauge - JCWhitney

Not sure if they're any cheaper or not anywhere else, just trying to get a good sense of which brand to go for. Assuming that 10 dollar Equus gauges wouldn't be much better than my 30 year old one that's in there already.

 

[Jimbos76cj]

Im not the greatest carb guy by any means but I thought that when a motor has a hard time starting once warmed up that its normally a vapor lock of heat soak problem. Make sure your fuel filter and fuel lines are not sitting on the manifold where the gas can heat up in the line.

As far as the choke working goes. When you got to start the motor step on the gas one time like the PO stated. That allows the choke to close. Once the motor is running the choke will heat up and open. It either heats up by the electrical coil warming up and opening or from the carb getting hot and radiating heat to the choke coil making it open. It may be that the choke is cooling off to fast and closing while the motor is still warm causing it to stall until the choke gets back up to operating temperature and fully opens.

When you first start it, it should idle high with the choke closed, once its been running for a little bit and you step on the gas it allows the choke to start to close by moving a cam on the linkage. Start the jeep let it warm up till the choke is all the way open.. shut it down and let it sit for the amount of time that it normally gives you the problem. Then step onn the pedal one time and see how far the choke closes. If it closes all the way then that is whats causing the motor to choke out and stall. It should only close about half way or less.

If its an electric choke run a hot wire from the battery and hook it to the choke plug. it should quickly warm up, turn the throttle and it should start to come off choke. if it doesn't move then you go a choke issue. Do this with the motor off. IF it works good while directly wired then start the motor, after letting the choke cool off and return to its normal position, and check the wire running to the electric choke for current. If you get a good light or voltage there that means your electric choke is working.

Stepping on the gas actually has no bearing on how far the choke opens, Even if you stomp on the pedal with the motor off it shouldn't move the choke plate open on most carbs.

Again Im not the best carb guy so this is just my wee bit of experience Hopefully some one else will chime in and correct me if Im wrong.

 

[1986cj7]

Im not the greatest carb guy by any means but I thought that when a motor has a hard time starting once warmed up that its normally a vapor lock of heat soak problem. Make sure your fuel filter and fuel lines are not sitting on the manifold where the gas can heat up in the line.

As far as the choke working goes. When you got to start the motor step on the gas one time like the PO stated. That allows the choke to close. Once the motor is running the choke will heat up and open. It either heats up by the electrical coil warming up and opening or from the carb getting hot and radiating heat to the choke coil making it open. It may be that the choke is cooling off to fast and closing while the motor is still warm causing it to stall until the choke gets back up to operating temperature and fully opens.

When you first start it, it should idle high with the choke closed, once its been running for a little bit and you step on the gas it allows the choke to start to close by moving a cam on the linkage. Start the jeep let it warm up till the choke is all the way open.. shut it down and let it sit for the amount of time that it normally gives you the problem. Then step onn the pedal one time and see how far the choke closes. If it closes all the way then that is whats causing the motor to choke out and stall. It should only close about half way or less.

If its an electric choke run a hot wire from the battery and hook it to the choke plug. it should quickly warm up, turn the throttle and it should start to come off choke. if it doesn't move then you go a choke issue. Do this with the motor off. IF it works good while directly wired then start the motor, after letting the choke cool off and return to its normal position, and check the wire running to the electric choke for current. If you get a good light or voltage there that means your electric choke is working.

Stepping on the gas actually has no bearing on how far the choke opens, Even if you stomp on the pedal with the motor off it shouldn't move the choke plate open on most carbs.

Again Im not the best carb guy so this is just my wee bit of experience Hopefully some one else will chime in and correct me if Im wrong.

I'm not sure about the carter 1bbl but my cater 2bbl bbd has a choke pull of that is set with the gas peddle pushed to the floor. And measured between the butterfly plate and the air horn. I have this problem some times and I have to hold the peddle to the floor or it will flood out, but I have been trying to get my choke set for a while now, when I rebuilt my carb the choke spring housing was busted up and not working at so I had to replace it.

 

[cdmcfarland]

Well picked up a mechanical gauge and it confirmed pressure issues. Seems to be pretty consistent now, after about 30 minutes of driving when the engine gets hot the psi drops to about 20-30 while driving and basically sits on 0 when in idle. Starting to stall out pretty frequently when in idle when it's hot, volts drop down below 10 and it will sputter out. Normally starts right back up.

I was hoping the sputtering was spark plug issues, but I'm pretty sure they would be missing all the time just not when it's hot. If I only run it for 20-25 minutes, you'd never know there was a problem!

 

[mtnwhlr]

Whats your idle set at?

 

[cdmcfarland]

How do I check that?

 

[mtnwhlr]

You would need a tach. You might just try turning it up some and see if it helps if you don't have one. Even if it's idleing a little high it's not going to hurt anything.