2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.

Low Compression?

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Old Oct 18, 2003 | 09:24 PM
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Low Compression?

Ugh... I'm hoping it aint true but the symptoms are crappy idle, low power and really hard time accelerating from idle (it backfires and puts). I kinda know it in the back of my head its probably true.. but for peace of mind what would be your diagnosis? *hopefully do a compression test tomolo to be sure....
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Old Oct 19, 2003 | 07:15 PM
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Could there be still hope?!
I did poor mans compression test and there were pulses from each rotor. Could anyone tell me how many pulses there should be for each *whine* of the starter? The pulses came at regular intervals though.
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Old Oct 19, 2003 | 09:50 PM
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ok, sounds like she's blow.

turn it over by hand, and watch for 3 pulses from each rotor. Do this with the plugs out.

Another way is to check the spark plugs after it has been running. If you take them out and one set(ie front rotor or back rotor) is covered with gas, the your looking at a rebuild.
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Old Oct 20, 2003 | 01:32 AM
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yeah its my worst fear I guess... just in denial =( I did take out spark plugs after it was warmed up a bit there wasnt any gas on the plugs but there was carbon... quite a bit caked on...
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Old Oct 20, 2003 | 06:27 PM
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well if there wasn't any fuel then it might not be blow. The reason why you check for gas on the plugs is because if it is blown, then it is not igniting the gas. If the gas is igniting, being burned, then all might not be lost. Are you sure you checked all 4 plugs?

Try cranking it over by hand, and see what you get. Pay close attention to how far apart the chugs are. Report beck here with the results.

You can even isolate the 2. Crank the good one over with the spark plugs out, while the other plugs in the suspected blown rotor are in. Get a baseline for what it should sound like. Then switch the plugs. Take out the ones that are in the rotor that might be blow and put the plugs back in the good one. test. see what you get.
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Old Oct 20, 2003 | 07:57 PM
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well I got new plugs and no diff really. I honestly dont know which rotor is even good... both sound about the same intensity in terms of strength of the pulses. both rotors sound about the same also. What I did was took out leading for rotor 2 and listened to sound and feel pulseswhile friend was cranking (spark plugs for rotor one T and L were both in). Then I put the leading back in for rotor 2 (rear) and pulled out leading plug for rotor 1 and did same thing. I did with with me listening and my friend listening and feeling pulses and couldnt tell much of a difference. I guess the real test comes down to an actual compression test....

My88SE: thanks alot for your advice and help. This is my first encounter with anything like this and its nice to have some guidance ^_^ Hopefully I can get some #'s from a piston compression tester and get back to you soon!
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Old Oct 20, 2003 | 08:02 PM
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Partsource carries a compression tester for about $20 - $30.

http://www.partsource.ca/resultsAB.html


That's where I got mine.
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Old Oct 20, 2003 | 10:36 PM
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o0o0 thank you muchies amur_ ^_^
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Old Oct 21, 2003 | 11:11 PM
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well I guess its dead =(
I did a compression test with one of those cheap piston compression testers and well its not pretty.... around 60psi on all faces on both rotors... Well I guess the truth really does hurt =( So any opinions on this or advice on rebuilds (What kinda seals to use, I heard of using a FD side seal?)?
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Old Oct 22, 2003 | 02:49 AM
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Don't give up hope yet!!! try changing the fuel filter
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Old Oct 22, 2003 | 02:56 AM
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Originally posted by Sa22c_guy
Don't give up hope yet!!! try changing the fuel filter
Yeah, that will restore engine compression
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Old Oct 22, 2003 | 04:45 AM
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Well, I tink the idea here is that all might not be lost.

How many miles are on te engine anyway Z3r0?

There is still a little hope.
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Old Oct 22, 2003 | 12:36 PM
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From: Edmonton Alberta
hopefullly not all hope is gone =(
there are about 30,000 km on this engine. Maybe a little background into my car would help:

its an 1987 N/A with a 88TII turbo strapped onto it. Since I wasnt able to get it dyno tuned yet its been running pig rich. The max boost I would have been able to hit at the time when the problem started was about 5 psi.

Also I think what he was trying to say was that maybe the fuel filter has been clogged? I do not know if its the original or not. The previous owner had the engine rebuilt. The reason for the fuel filter being clogged is because I run premix. I do not know if this affects the fuel filter or not.

But Thanks alot guys for your help and support ^_^ and hopefully we can think of something but if a rebuild is what it needs then I guess its reality =(
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