first off im not that good working on cars. i love doing it but i dont have the experience and my dad just said hes a bit of a dunce. to make the long story short i did a compression test today and #3 is 115 and the others are 170. i have a 94 GSR btw. could it be at all possible that i have a bent valve in 3 for the compression to be low or is this way to low to have a bent valve...is it more serious than a valve? what should i do? leakdown test?

 

When you have a bent valve, you have 0 compression.

 

to help narrow it down, go out there and put some oil down in the #3 cylinder. After you do this re do the compression test on that cylinder. If the numbers go up then its your rings. If it stays at 115 you most likely have a valve problem and you will need to perform a leakdown test to help narrow it fuether. Good Luck

 

I have complete stock valvetrain if interested....
cheap...... low mileage.....

email me if interested...........

 

thanks guys. i did the table spoon of oil and the compression went from 90 to 170 where all the other cylinders were at. so its a ring. now what? my car ran totally fine earlier today. infact i was going to take it to the track on friday night. guess not anymore.

MORE HELP - also now my car wont start. there is no spark. i have no idea what to do. any ideas

 

let me guess... you were cranking it during your compression test with just the sparkplug wires hanging. check for spark, if none i'd bet on the ignitor. could be the coil too but ignitor is more suspectable to damage.

 

what's the proper method?

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by stumpyf4 &raquo;</TD></TR><TR><TD CLASS="quote">let me guess... you were cranking it during your compression test with just the sparkplug wires hanging. check for spark, if none i'd bet on the ignitor. could be the coil too but ignitor is more suspectable to damage.</TD></TR></TABLE>

 

your prolly didnt unplug your distributor when you did the test and fried your ignition coil,.....test it using an ohm meter and the go buy a new one if its bad....i think they are like 100$

 

what do you mean "didnt unplug your distributor when you did the test and fried your ignition coil". how do i unplug my distributor? i took out all plugs not just the cylinder 3 that i was testing. yes i was cranking it over with the wires just hanging...thats what the instructions said.

 

unplug the diz? - i thought all you had to do was take the plugs and fuel fuse out

 

i didnt take a fuel fuse out...it wont turn over with no plugs in

 

dude come on - did you bother to get instruction, or did you just wing it - not to be an ******* but if you did **** it up, think of it as a lesson learned - why else would you use this site if not for info - c-speedracing has a how to and yes the car will turn over w/out the plugs - how did you test compression w/ the plugs in btw?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Boost2NA &raquo;</TD></TR><TR><TD CLASS="quote">to help narrow it down, go out there and put some oil down in the #3 cylinder. After you do this re do the compression test on that cylinder. If the numbers go up then its your rings. If it stays at 115 you most likely have a valve problem and you will need to perform a leakdown test to help narrow it fuether. Good Luck</TD></TR></TABLE>

wtf that doesnt make sense, what if you do that in a normal car( car that has no compression problems)

 

i read the instrutctions on the back of the box of the compression tester. i did take the plugs out, you have to. i dont know where i meesed up. somethin is messed up now. so now i need new rings and a coil...im havin a bad day

 

i know what i did wrong now

"The first step is to remove the spark plug cover and plug wires. Then make sure that you remove the 15A fuse in the fuse box that control the FI injection. That way when you crank the motor over no fuel will be squirted into the cylinders."

c-speedracing.com

 

or you can pull the 10amp fuse for the ecu and disconnect the distributor from the engine bay wiring harness

 

how do i check to see if my ignition coil is still good?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tilt &raquo;</TD></TR><TR><TD CLASS="quote">what's the proper method?

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If you just unplug the wires and leave them dangling the voltage to jump across the spark plug will sky rocket way past the 40,000 or so v0lts it takes to jump across the sparkplug. It'll go up to what voltage it take to discharge. It may even discharge back into the distributor and fry the ignitor. If the voltage demand is too high the coil may even fry out.

To test the coil:
1) Remove the distributor cap
2) Remove 2 screws to disconnect white/blue wires (terminal A) and black/yellow (terminal B).
3) Measure the resistance between the terminals A and terminal B. This is not the wires but where the wires were connected to. Should be 0.6-0.8 ohms
4) Measure the resistance between terminal A and the acutal discharge terminal (where the distributor cap touches, end of the tower. Should be 12.8-19.2 ohms.

Ignitor check is more indepth.

 

hmm, so i take it the proper method is to disconnect the distributor wiring harness?

 

Reinsert the spark plugs into the wires. Ground out the spark plug using some wire wrapped around the threads.

I'm not sure if tdisconnecting the dizzy harness will do it.