Well, guys, I don't know if my car is sick or not...

This all started when Ben, our fearless leader, drove my car a few weeks ago to check out the gen 2 Hyperco springs he's expecting, since I've got them on my car. His immediate impression had nothing to do with the suspension, however; the first thing he said was that my car is slow, especially for the mods I have. So you know, these are (car is a 94 lowport classic): Hotshot gen 4 header, HS short stack intake with POP, 91 intake cam.

Since then and largely on his advice I have done the following:

1. Adjusted throttle cable
2. Set timing higher - it was supposed to be at 15, was more like 14, and now it's at 17. Ben's is at 19.
3. Changed fuel filter. I think the one I took off was the original, and the car has 125k miles on it :eek:
4. New cat is on the way - I doubt this is the problem, ***.

After the filter and timing, the car is noticeably faster. Don't know if it's fast enough for Ben, but faster just the same.

Here's my concern: I did a compression check tonight, just to cover the bases. I've never done one before, and I got a checker from AutoZone; it was the only model they had. Engine was nice and warm. The first time I did it I had the included "long reach" adapter on the end of the hose, but it stayed threaded in the spark plug hole and I had a hell of a time getting it out, so I didn't use it the rest of the time. Re-warmed engine, and readings were:

120-115-125-145

I don't get it; is the only symptom of low compression loss of power? When I had the "long reach" thing on, cylinder 1 read 155; did that have something to do with it?

I know the exhaust cam can affect compression; I don't have time these days to pull the VC to look at it ***.

I'm freaking out here; is it needless? My wallet doesn't want to buy a JDM motor, no matter how much I might like a nearly new engine... Can anyone shed any light on the situation?

Kent I honestly do not not know how low is to low for compression. I just recently did a compression check on my car and I got 172 all across. This is on a 9.5:1 JDM . Does the car burn any oil Kent? Lets help him out gang!!

Did you hold the throttle plate open during the check? Last time I did my car, it was also at 172 across the board on my original 140K mile motor...

Thanks for the replies guys!

Rob -
AFAIK, car does not burn more oil than it should - I am using synth on a high-mileage engine. I lose a bit, but I'm 99% sure it's all going to a leak around the front cover. I do get a drip in the floor every other day or so, and the car loses about a third of a quart in 3000 miles. Nissan wants $700 to re-seal the front cover :rolleyes:

Chris -
I am a moron. I did NOT hold the throttle plate open. I did the other night when I did one cylinder to get a feel for things; let me do that tomorrow night and I'll post new results.

Originally posted by Rittmeister
Thanks for the replies guys!

Chris -
I am a moron. I did NOT hold the throttle plate open. I did the other night when I did one cylinder to get a feel for things; let me do that tomorrow night and I'll post new results.

Kent I am pretty sure that is why teh compression #'s are so low. Please let us know what happens when you re-do the check tomorrow.

Haha, I did the same thing the first time I checked my compression. I was in the 120's. After holding the throttle open I got something like 179 179 178 177. Good luck. If you still have a power problem, join the club! I swear I will find out whats wrong!

When I did my compression test on my ga16 I did the same thing. I didnt hold the throttle open. my motor is crap right now. put it this way the numbers are not supposed to drop below 170psi on my engine. The first time i did the test with the throttle closed I got something like 135 145 150 145. then I realized that i didnt hold the throttle open and redid the test and I still only got 150 155 160 155 which is way below what it is supposed to be. holding the throttle open didnt make a whole lot of difference when I did it but a little. anyways my engine has low compression and that is why it is only putting down very little power. my car burns a quart of oil every 150 miles or so. so that is why I got a jdm ga16 engine and im pretty sure this will solve all the power problems. by the way I have a cai, header, highflow cat, and full 2 1/4 inch exhaust with a straight through performance muffler and all of these mods didnt make any power difference to the wheels. I still ran the same time as I did before all of these mods. so im going to be happy after I put my engine in this thursday. Ive already taken it out once so It will be a breeze. maybe 5-6 hours in and out. my engine idles very rough and misses all the time and it just doesnt have any power at all.

on a side note. I got my engine from nippon motors and ill tell you what I am very happy with the quality of this engine. This engine was very clean and when I took the oil pan off there is no oil varnish at all and the oil that was in there was very clean. was a dark brown color. this engine seriously looked like it only had about 20-30k miles on it. there were no burned oil marks in the inside so this engine was never overheated and never ran low on oil and it didnt have any leaks. I still replaced all the seals and everything when I took the valve cover off it was spotless. There was no oil varnish and no burn marks on the the bottom of the valve cover like mine has. Mine is all brown on the bottom this one was spotless not one varnish or burn spot on it. all of the cam lobes dont have one scuff mark or burn mark on them. they are shinny, spotless and smooth. I think there was only one lobe that had a scuff on it and it was a very small scuff and it was right where the lobe starts to lift the valve. it wasnt actually the lobe. anyways the inside of it around the cams was also spotless and the little traces of oil that was still in the engine was very clean. So this engine had to have been really taken care of through whatever little life it had before it was pulled. So I am highly recomending nippon motors. they were right when they said that I would be happy when I get the engine and I am and I cant wait to put it in and feel the difference and feel what I have been missing even though i will be selling the car right after it is put in but hey it is a ga16 what do you expect. but I figure it should put about 100-105hp to the ground when it is in. I figure that right now I am only putting about 70-75 hp to the ground that is how messed up my engine is right now. sorry for the length but I was just very impressed by the quality of this engine. Even though I know this engine was well taken care of it couldnt have much more than 30-35k miles on it. very good quality engine. thanks for reading.

has anyone else bought engines from this company and how was the quality.

Update:

New compression check with throttle open (thanks Chris ;)):

155-155-160-160

This is well within factory spec according to my FSM, as well as being nearly the same across the board. It's my belief that the numbers are actually higher than this; trying to get a tight seal in the spark plug well with a rubber hose is difficult. I think if I had a comp tester that had a steel hard line long enough to thread into the plug socket that the numbers would be higher.

So, it appears that compression is not the problem, and that my cams are OK (or all four lobes are a little bad :eek:), and that the headgasket is also OK. The car continues to lose oil, but this is now without a doubt a leak; I have had drips on the floor every morning for the last few days, and I didn't just do an oil change. My mechanic and I are going to put this bad boy on the lift on Friday afternoon to see where the leak is coming from, and we'll go from there. When I told him the whole front cover story, he thought that price was outrageous, so if we need to do that hopefully I'll make it out with all my arms and legs. I will of course keep y'all updated.

Thanks for all the help!

That does look as if your getting close to the minimum numbers though. Isnt it at our around 150?