I just got my motor rebuilt and for some reason the car was'nt idling well at all. When it was given to me from the shop to break it in it would die at almost every light. There was some excessive ticking so I figured i'll take it easy on her till I get it tuned.

After the valve adjustment the car sounded noticeably better, yet the uncureable idle was still there. We wound up doing a compression test and the results were
Cyl 1: 200, Cyl 2: 190, Cyl 3: 160, Cyl 4:190
For a motor with only 150 miles on it do these numbers seem low or am I nuts?
Could it be that the rings are not seated yet? I have not abused it at all since I got her back and this will be third motor rebuild in three years!!!!

Any help or advice would be greatly appreciated, setup is in sig.

 

go back to whoever built your motor and work it out with them.

if you cant determine whether your motor is "right" or not, may i suggest a search?

 

To me those numbers sound really low for a freskly built engine, i would have thought a rebuilt would get at least 220 per cylinder.

You should definantly take it back, doesn't sound like it was right from the get go.

 

How freshly built is it? How many miles have you put on it? Drive it around for a little longer to make sure the rings have sealed properly first.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Jowee 1162 &raquo;</TD></TR><TR><TD CLASS="quote">How freshly built is it? How many miles have you put on it? Drive it around for a little longer to make sure the rings have sealed properly first. </TD></TR></TABLE>

Yah. 150 miles. Read Joey

Still using dinosaur (non-synth) oil? You should be.

On my motor with JE pistons, I put about 100 miles (moderate to hard) on it and then went to an HPDE. I'm pretty sure that broke it in.

Regardless, I'd give it a few rips, another hundred miles, and check it again. Different compression testers give different results. You've got a bit of skew in there but it shouldn't be enough to make much of a difference to idle or dyno (a few percent, maybe?)

I would personally be a little harder on it, get it to the stock redline a few times, and check it yourself while it's still hot.

Whip Factory in Plainfield did my motor. No real issues with any of the work he's done so far! I had one issue I was able to fix myself (moving an oil line away from my downpipe), and charge pipes blew off once, whatever. Oh, and somehow the intake cam bolt started backing out.. *shrug* Not too bad considering it was a motor rebuilt, turbo replacement and retune.

-Chris

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by S(J)O(D)L(M) &raquo;</TD></TR><TR><TD CLASS="quote">yet the uncureable idle was still there.</TD></TR></TABLE>

What tuning, can you refresh my memory?

There's a Helms instruction for setting the idle screw on the throttle body.. something to the effect of disconnect the IACV, and turn it until you get it to 500 RPM.

 

The problem was that the car would not idle well at all. We did what we could including playing with idle screw. after the compression test we realized why we could'nt get it to idle. I'm done with the B series and going with a K20 head with a K24 bottom end and filling it with Toda bliss.......now i'm just waiting for DAN GSR to get back to me to see if he wants to tackle the project.

 

have fun with a torquey car

are ur valves sealing properly? piston rings? did u try adding a couple drops of oil in there?

 

When we added a couple of drops of oil in the compression shot way up.

 

I think you should beat on it a lil more

rings may seal better

 

I've kept the revs below 5k. You think I should get on it a lil harder?

 

Wail it!!! it's never going to seat 100% unles it sees 100% throttle.

 

It should idle perfect on that compression.

When you get it down towards 60 PSI, it gets a little lopey. But mine idled fine on 3 cylinders after the spark plug fouled.

Endyn "take it easy" break-in (standard, classic one.)
(can't find link)

Alternate (wail it!) break-in. Interesting read, valid points IMO.
http://www.mototuneusa.com/break_in_secrets.htm

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Bbasso &raquo;</TD></TR><TR><TD CLASS="quote">Wail it!!! it's never going to seat 100% unles it sees 100% throttle.</TD></TR></TABLE> 100% correct

 

So, essentially you guys are saying I should go pick the car up from the shop and just drive it harder?

 

I would.

 

Well, I guess i'll go pick up my car and drive it till DAN GSR builds me my K20. Thanks for the help.

 

Beat the **** outta it. It's not like you've got anything to lose.

 

I find the whole situation discomforting knowing that my compression levels were that low after 150 miles.I've seen many posts through searching that most R numbers are in the area of 220 and above. If the rings are not yet seated, is it possible to correct the issue by driving the car some more? Or am I at the point where the damgage is done and the bottom end needs another rebuild?

 

the questions you just asked, weren't they answered above?

drive it like you stole it to break it in... the mainpoint of above.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by S(J)O(D)L(M) &raquo;</TD></TR><TR><TD CLASS="quote">I find the whole situation discomforting knowing that my compression levels were that low after 150 miles.I've seen many posts through searching that most R numbers are in the area of 220 and above. If the rings are not yet seated, is it possible to correct the issue by driving the car some more? Or am I at the point where the damgage is done and the bottom end needs another rebuild? </TD></TR></TABLE>

If they don't ever seat properly, possibly it might need a rehone and new rings. Not a full rebuild. The rough edges from the hone can wear down before the ring seats properly, and at that point it'll never really seat.

It depends on the compression tester though. My personal one reads 225+ on stock B18C5 cylinders. I took it to a shop that read 170 on the same cylinder. YMMV.

Also, there's no telling that it's definitely the rings. Could be valves. Could be cam timing, I suppose... maybe... maybe someone else can comment on how retarded your intake cam would have to be to show a loss of compression.