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1 compression test question and 1 starting question.

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topnotchgsx

20+ Year Contributor
104
1
Nov 4, 2004
Warrior, Alabama
Well I just recently rebuilt my 6-bolt into a stroker motor and everything went perfectly fine without a problem. Well I have about 1200 miles on it now and have never been able to go over 12 psi due to my ### ebay intercooler pipes and couplers always blowing off. Getting those fixed soon. LOL. But my question is that I have been using up a ton of oil everytime I drive it for a while. And I know that my turbo needs a rebuild, and I know that oil was leaking past the seals, but I was still worried it was something inside my motor because it was using to much oil for me to feel like it was just the turbo. So I do a compression check to make sure my rings were fine and the numbers came out to 190-178-190-190. All good except for the 178. I am runnin ross 9.0:1 compression pistons. Should I be worried about the 178? Keep in mind that my head is COMPLETELY stock. I am gonna rebuild it next when I get some more money. I dont have access to a leak-down, but do you think that it could just be a bad valve seal that is giving me the 178? If so, then that will be taken care of with the head rebuild?

My next question is about when I start my car. I bought an AEM EMS system for my car before I ever rebuilt the motor and had some tuning issues I needed resolved, so I took it to a shop that I trust, and they fixed some problems like a TPS that was wired incorrectly and did a tune. They just got the tune real good at idle because they could not street tune bc my clutch was absolutely shot. And ever since I got my car back from there, when I go to crank it, it takes about 10-15 seconds for it to finally fire up. The motor turns, and turns, and turns, before it finally fires up. It doesnt matter if the engine is completely cold or completely warmed up. I dont know anything about my EMS, so I am wandering if this is a feature on my EMS to get the engine and turbo primed will oil real good before it turns over? If not then what could this be? I believe it is just something to do with the EMS, and it is not a big problem, I just have always wanted to know why it does that and if I could set it to fire up quicker.

Sorry for the extremely long post, I just like to go into detail. LOL. Thanks for any help!


Keylan
 
Anybody? I know that they arent difficult questions, LOL , but I figured someone could help.

Keylan
 
You have to read how the compression rises on that cylinder to assist in determining why. Any number of leaks or worn components can cause slightly low compression.

I would first check your fuel pressure, seems like it is losing prime. Perhaps whoever tuned it is not retarding the ignition enough to start easily. What is the AEM pulling the timing back to during a start?

Beyond that, I dont know anything about AEM. Sorry.
 
usually numbers within 10 psi of eachother are deemed acceptable. leakdown test the motor. i probably wouldnt be too worried about it. just keep a periodic eye on it and see if that cyl deteriorates.
 
my compression gauge hose also doubles as my leak down tester, all you need is to regulate the air pressure from your compressor, a cheapo inline vale ,available at any parts store, works good enough.
could be a valve not seating in your low cylinder, always have your head done with a rebuild, cheaper then than it is going to be now.
was it a rering rebuild or was it bored out for rebuild, some rings take longer to get settle in especialy if the cylinders were not left with the correct finish on them.
im not sure about the ems system, good luck.
 
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