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How low is to low for compression? EA82T


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So i have been chasing the cause of the reason for my car to be running rough. its a 90 Loyale with the EA82T 4wd 5 speed. So at the moment the car is not building any boost and its running choppy. I runs and drives still but it is VERY slow. So far i have checked and reset the timing and the ignition timing. BEfore i reset the timing i was reading 0* ignition timing on my gun after i reset it im up to about 5* (to my knowledge i need to be at 20*). I do believe that the turbo may be damaged as it is making a ticking noise and it gets louder with revs. I had the manifold welded a few months back and i have a feeling that a chunck of slag from the welder broke off into the exhaust and ran through my exhaust wheel. I have not check yet but i will be doing so this weekend.

 

BUT

 

today i ran a compression test on my engine today and got some unfortunately low numbers.

 

cylinder #1 = 90 psi

cylinder #2 = 110 psi

cylinder #3 = 90 psi

cylinder #4 = 100 psi

 

all these numbers were taken after about 7 to 8 cranks on the motor. I ran the engine for about 10mins before i tested it and i held the throttle open while cranking. when i first would crank the engine over i would only jump to about 20-30psi. From my knowledge these numbers are not great but i figured that i would run it by you guys and see what you thought.

 

thanks

 

 

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Nunbers don't look too bad to me. Remember the CR is only 7.7.  A quick way to test the turbo is to pull that vacuum line between the intake manifold and the wastegate controller. This will produce maximum boost, if the turbo is not damaged. And I do mean maximum. Do this only as a test. 

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Well I pull the vacuum line and still no boost. So I took the turbo off. Seems like it was pretty hard to turn. I believe it may have been oil starved. Either way I got a new one in the mail so hopefully I can get some boost soon. But I'll have to take out the lines to the turbo and see if they got clogged or something. Hopefully I can figure everything out

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well the manual says 130 psi, which is what I usualy find on comp tests, but my Vortex spider pumps out 150 :)

 

One of my EA82T I bought cheap was the smoothest, most torquiest of all EA82T - quietest too....yet it had some blow by isues up hills. A comp test showed 120 in three pots, and just half in the poop cylinder. The weird thing is I could not sense any idle issue, no stumble on take off, no miss of any kind.

 

On tinkering with a blow off set up on another EA82 I had the boost being diverted too long ( a design issue of mine) did not boost until 4000rpm and then whack! it would come in trying to take me to the next millenium. Up until that 4000rpm it was painful to drive - no go at all.

 

Sounds like another turbo with an oil supply will fix your woes - check its oil pressure huh ?i

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  • 1 month later...

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