Hi. This is my first post on this forum. By a matter of fact, it is the very first time I have to look for help with my 1982 CJ7 258 6 cylinders engine. So far this car has been so loyal to me....the thing is there is no way I can start it. So far, this car has always been starting without problem . But, I have not started it for the past six months, and now I find out something happened for not using it for so long. I know, a car is made for using it, not leaving it standing by at the garage....now I am paying the consequences.
The starting motor is running fine. I first thought it was the battery that was tired, so I bought a new battery. No starting... I check the ignition system, and I do have sparks. I cleaned the spark plugs. I checked the distributor and found it has a nasty sticky durty stuff in it, near the pickup coil, so I replace the pickup coil assembly. Still no starting. Then I remember that when I last started the engine, I was very low on gas, so I thought maybe some dirty particles went into the fuel system. So I moved to the carburetor, disassembled it fully, cleaned it, rebuilt it using a carburetor kit to replace the small stuff that can be easily replaced. To discard a dirty gas tank, I decided to use a small plastic outboard motor tank connected at the gas pump inlet ...Still no starting. I then thought that maybe the starter motor was a little bit tired to move the motor fast enough, so I disassembled it, find out it has already been repaired, had a bad wiring connection, corrected the problem, cleaned everything, reassembled..... still no starting.
I don’t have to say that at that point this is starting to annoy me.
A friend of mine who has quite a good experience in mechanic checked the problem with me and, placing his hand on top of the carburetor when trying to start the engine, he immediately points me out that the vacuum was very poor. He told me that the problem might be that the hydraulic valve tappets have lost pressure and needed to be “rechargedâ€, using a electric drill to rotate the oil pump ( after removing the distributor ). I have done it, removing the cylinder head cover to check that oil was coming out of the push rods, and it does. I replaced the distributor, check the timing ( rotor facing spark plug #1 when timing index on damper face TDC on timing scale ), and still the engine refuses to start. So I thought it was time to do a cylinder compression pressure test. I knew the engine was worn and needed to be rebuilt, but I was quite surprised by the numbers I got : 60 psi for all but one cylinders, and 45 psi for the #5 cylinder. This is really low. So my questions are :
#1 : does the very low compression in the cylinders can explain that the engine refuses to start.
#2 : what can have caused this collapse in the compression values, related to a long period of not starting the engine ( before this period, the engine was starting just fine ! ) ?
#3 : any idea of what is happening, what should I check next ?
Any help, comment, suggestion is welcome !
Thanks to all.
Jean-Christophe
San Antonio, Venezuela
1982 CJ7 258 engine
The starting motor is running fine. I first thought it was the battery that was tired, so I bought a new battery. No starting... I check the ignition system, and I do have sparks. I cleaned the spark plugs. I checked the distributor and found it has a nasty sticky durty stuff in it, near the pickup coil, so I replace the pickup coil assembly. Still no starting. Then I remember that when I last started the engine, I was very low on gas, so I thought maybe some dirty particles went into the fuel system. So I moved to the carburetor, disassembled it fully, cleaned it, rebuilt it using a carburetor kit to replace the small stuff that can be easily replaced. To discard a dirty gas tank, I decided to use a small plastic outboard motor tank connected at the gas pump inlet ...Still no starting. I then thought that maybe the starter motor was a little bit tired to move the motor fast enough, so I disassembled it, find out it has already been repaired, had a bad wiring connection, corrected the problem, cleaned everything, reassembled..... still no starting.
I don’t have to say that at that point this is starting to annoy me.
A friend of mine who has quite a good experience in mechanic checked the problem with me and, placing his hand on top of the carburetor when trying to start the engine, he immediately points me out that the vacuum was very poor. He told me that the problem might be that the hydraulic valve tappets have lost pressure and needed to be “rechargedâ€, using a electric drill to rotate the oil pump ( after removing the distributor ). I have done it, removing the cylinder head cover to check that oil was coming out of the push rods, and it does. I replaced the distributor, check the timing ( rotor facing spark plug #1 when timing index on damper face TDC on timing scale ), and still the engine refuses to start. So I thought it was time to do a cylinder compression pressure test. I knew the engine was worn and needed to be rebuilt, but I was quite surprised by the numbers I got : 60 psi for all but one cylinders, and 45 psi for the #5 cylinder. This is really low. So my questions are :
#1 : does the very low compression in the cylinders can explain that the engine refuses to start.
#2 : what can have caused this collapse in the compression values, related to a long period of not starting the engine ( before this period, the engine was starting just fine ! ) ?
#3 : any idea of what is happening, what should I check next ?
Any help, comment, suggestion is welcome !
Thanks to all.
Jean-Christophe
San Antonio, Venezuela
1982 CJ7 258 engine
The compression values do sound low, but it still should fire - though it probably won't run worth a darn. Wish I could help more.
