Bad Compression??? 88 N/A
07-31-10, 10:29 AM
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Bad Compression??? 88 N/A
I've got an 88 RX7 with 105k original miles on it that has sat in a driveway for a little over a year. Had a 1/4 tank of gas in it and had a bad fuel pump, that is why it sat for so long. I bought it, messed around with it for a little bit. Got spark, got fuel, timing is good, crank sensor is good, BUT NO START... I finally checked compression. I have read that checking compression on a cold engine is no good BUT I have saw a few posts of people doing it cold and still getting way higher results than I'm getting. I've tried oil in the housings with WOT and I'm getting 15psi on two faces and 25psi on the third. About the same for both rotors front and back. My only guess is that it sat so long and the apex seals have gunked up and are stuck. When I crank the engine with everything in working order, it is burning something because a little bit of smoke comes out of the exhaust. I figured even with that low of compression if it is truly that low it would still make more of a cumbustion sound than nothing at all. I've gotten the car to sputter and die once but nothing close ever since... ANY IDEAS ON WHAT MAY BE WRONG OR SOLUTIONS TO FREE UP THE SEALS OR GET THIS THING RUNNING???
07-31-10, 10:38 AM
#4
Put some Marvel Mystery Oil or ATF in the spark lug holes, put the plugs back in and spin it around by hand a couple of times.
Let it sit overnight, spinning the engine from time to time.
In the meantime go get new spark plugs, I dont care if they are new just do it because of the ATF. Then make sure you have good gas and everything is hooked up and the battery has a full charge.
Next day spin the engine around some more, remove the plugs, spin some more and see that you get 3 puffs out of each rotor housing. Put new plugs in and go to town trying to start it.
If this fails see if you can get some buddys together and push start it, thats how I got one an engine that had been sitting for a while started, and once it gets going just hold it to the floor until it clears up.
Let it sit overnight, spinning the engine from time to time.
In the meantime go get new spark plugs, I dont care if they are new just do it because of the ATF. Then make sure you have good gas and everything is hooked up and the battery has a full charge.
Next day spin the engine around some more, remove the plugs, spin some more and see that you get 3 puffs out of each rotor housing. Put new plugs in and go to town trying to start it.
If this fails see if you can get some buddys together and push start it, thats how I got one an engine that had been sitting for a while started, and once it gets going just hold it to the floor until it clears up.
07-31-10, 10:55 AM
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I've got an 88 RX7 with 105k original miles on it that has sat in a driveway for a little over a year. Had a 1/4 tank of gas in it and had a bad fuel pump, that is why it sat for so long. I bought it, messed around with it for a little bit. Got spark, got fuel, timing is good, crank sensor is good, BUT NO START... I finally checked compression. I have read that checking compression on a cold engine is no good BUT I have saw a few posts of people doing it cold and still getting way higher results than I'm getting. I've tried oil in the housings with WOT and I'm getting 15psi on two faces and 25psi on the third. About the same for both rotors front and back. My only guess is that it sat so long and the apex seals have gunked up and are stuck. When I crank the engine with everything in working order, it is burning something because a little bit of smoke comes out of the exhaust. I figured even with that low of compression if it is truly that low it would still make more of a cumbustion sound than nothing at all. I've gotten the car to sputter and die once but nothing close ever since... ANY IDEAS ON WHAT MAY BE WRONG OR SOLUTIONS TO FREE UP THE SEALS OR GET THIS THING RUNNING???
Put some Marvel Mystery Oil or ATF in the spark lug holes, put the plugs back in and spin it around by hand a couple of times.
Let it sit overnight, spinning the engine from time to time.
In the meantime go get new spark plugs, I dont care if they are new just do it because of the ATF. Then make sure you have good gas and everything is hooked up and the battery has a full charge.
Next day spin the engine around some more, remove the plugs, spin some more and see that you get 3 puffs out of each rotor housing. Put new plugs in and go to town trying to start it.
If this fails see if you can get some buddys together and push start it, thats how I got one an engine that had been sitting for a while started, and once it gets going just hold it to the floor until it clears up.
Let it sit overnight, spinning the engine from time to time.
In the meantime go get new spark plugs, I dont care if they are new just do it because of the ATF. Then make sure you have good gas and everything is hooked up and the battery has a full charge.
Next day spin the engine around some more, remove the plugs, spin some more and see that you get 3 puffs out of each rotor housing. Put new plugs in and go to town trying to start it.
If this fails see if you can get some buddys together and push start it, thats how I got one an engine that had been sitting for a while started, and once it gets going just hold it to the floor until it clears up.
As far as the other two replies, I have fuel and the coils are good. I got spark on all for plugs (strong spark trust me I pulled away while it was still firing and got shocked) and plugs get wet when I crank and pull them out.. thanks
P.S. I don't know why it is trying to quote my post AND your reply, just wanted your reply
07-31-10, 11:31 AM
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Thanks I appreciate it. The car has about 1/4 tank bad gas and I put 5 gallons of 93 in it to try to up the shitty old octane. I will pick up some premix and atf soon (cable guy is here haha) and I will get right on working on it. Trying to get it street worthy asap so I can get rid of my beater *** truck And make room for my MR2T
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07-31-10, 11:55 AM
#8
If your plugs are getting wet then the engine does not have enough cranking compression. Get the battery charged and tested or take another battery from a known good source and install it. Then pull the plugs and disable the fuel system and crank it over until there is no more evidence of fuel coming out of the spark plug holes. Then reinstall the plugs and re-crank.With the key to just the "On" position do you hear the fuel pump come on?
Thank you. I will get right on that. I love this car and want it to run so bad. The car is in great shape for sitting so long I hate to see it go to waste. I will keep you posted on what goes on.
As far as the other two replies, I have fuel and the coils are good. I got spark on all for plugs (strong spark trust me I pulled away while it was still firing and got shocked) and plugs get wet when I crank and pull them out.. thanks
P.S. I don't know why it is trying to quote my post AND your reply, just wanted your reply
As far as the other two replies, I have fuel and the coils are good. I got spark on all for plugs (strong spark trust me I pulled away while it was still firing and got shocked) and plugs get wet when I crank and pull them out.. thanks
P.S. I don't know why it is trying to quote my post AND your reply, just wanted your reply
07-31-10, 07:57 PM
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I've got a few month old red top Optima battery in it so i know i'm good in the cranking area. It's about 13volts right now, just charged it. And I did remove the plugs and cranked until no more fuel came out. With the key to just the "On" position the pump does not turn on but i read that it is not supposed to turn on unless the engine is cranking. The pump turns on during cranking and i know for sure the pump works because it is a brand new Walbro 255 i just put in last week. When i jumper the connector to make the pump come on when the key is turned to just "on" it kicks on... So it leaves me to low compression which i have....
If your plugs are getting wet then the engine does not have enough cranking compression. Get the battery charged and tested or take another battery from a known good source and install it. Then pull the plugs and disable the fuel system and crank it over until there is no more evidence of fuel coming out of the spark plug holes. Then reinstall the plugs and re-crank.With the key to just the "On" position do you hear the fuel pump come on?
07-31-10, 07:58 PM
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Haha no all the plugs were in except for the one that was out for the Compression tester to be in of course. i did it one plug at a time
07-31-10, 11:44 PM
#13
At this point I would recommend to do as safely as you can. Meaning no other cars around, etc. To have someone pull you with the transmission in 3rd gear.
I have had some engines that just sat too long and would not fire unless I pulled them behind my truck. After doing the above they started right up.
Hopefully your injectors are not stuck open or are so bad that they have a bad spray pattern and are causing the issue also.
I have had some engines that just sat too long and would not fire unless I pulled them behind my truck. After doing the above they started right up.
Hopefully your injectors are not stuck open or are so bad that they have a bad spray pattern and are causing the issue also.
08-01-10, 12:09 AM
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At this point I would recommend to do as safely as you can. Meaning no other cars around, etc. To have someone pull you with the transmission in 3rd gear.
I have had some engines that just sat too long and would not fire unless I pulled them behind my truck. After doing the above they started right up.
Hopefully your injectors are not stuck open or are so bad that they have a bad spray pattern and are causing the issue also.
I have had some engines that just sat too long and would not fire unless I pulled them behind my truck. After doing the above they started right up.
Hopefully your injectors are not stuck open or are so bad that they have a bad spray pattern and are causing the issue also.
08-01-10, 12:33 AM
#15
Have someone pull you with the transmission in 3rd gear and it is spinning the engine. Disable the fuel and spark while you do this.
You should only have to go a mile or less when you do this. Then stop and put the plugs back in, reattach your coil wires and enable fuel and crank. If it does not start then proceed with towing again. :-)
You should only have to go a mile or less when you do this. Then stop and put the plugs back in, reattach your coil wires and enable fuel and crank. If it does not start then proceed with towing again. :-)
08-01-10, 10:07 AM
#16
If all else fails drain all of the gas out of your tank and put all new gas in it with a bottle of fuel injector cleaner. I think they may make some water removal additive you might try first.
If water has accumulated in your tank while it sat, then I'd bet you're not going to get it to run on water, unless you somehow convert it to a steam engine.
You could try soaking it in SeaFoam overnight (I would bet it's safer on your seals than ATF), I doubt you have enough compression to create enough vacuum to suck it in the engine that way, but you could add it via the spark plug holes and turn it over a few times every 3-4 hrs.
I'll second that you need to get some new plugs. Once you do get it to fire up it won't be very long and will need replacing. If you're like me, you'll probably have to have the parts store order you some, or order them yourself.
Good Luck
If water has accumulated in your tank while it sat, then I'd bet you're not going to get it to run on water, unless you somehow convert it to a steam engine.
You could try soaking it in SeaFoam overnight (I would bet it's safer on your seals than ATF), I doubt you have enough compression to create enough vacuum to suck it in the engine that way, but you could add it via the spark plug holes and turn it over a few times every 3-4 hrs.
I'll second that you need to get some new plugs. Once you do get it to fire up it won't be very long and will need replacing. If you're like me, you'll probably have to have the parts store order you some, or order them yourself.
Good Luck
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