Evaluate my Comp. Numbers,Please.

[markjw]

1994 Loyale,5sp 4wd wagon.Bone Stock.

 

1-135

3-140

2-155

4-135

 

The car isn't running right. I completly resealed the motor and installed a new timing kit. I bought it condition unknown so,I don't know how it ran before I did all the work.

 

I have gone over the timing several times.Both the belt timing and the dizzy timing. It's right.I know it is.

 

I had the heads shaved and pressure tested,too.New valve stem seals.

 

New plugs (NGK)

Wires

Cap & Rotor

Air filter

Fuel Filter

Fuel Pump is good,at least it works fine on my other loyale.

 

You get the idea. Pretty much everything that should be replaced,I replaced.

 

It's gotta be a sensor.I checked the codes and the only thing going on with the green ones connected is the repeated 5 quick flashes over and over.I guess that means notheing is wrong.

 

With the white ones connected,I get EGR solenoid. And that's it.

 

It starts fine,idles nice and smooth.Seems to have good power on the 1-2 up shift,but starts to fall on it's face from the 2-3 and up. It feels like it's sputtering and missing at cruising speed.Not much,but a noticable amount.Lack of power,too

 

It just doesn't run very well at cruising speed.

 

Here's my questions...

 

What do you think about the comp. numbers? Could that be a factor?

 

Also,could the 02 senser be bad,or some other sensor,and not throw a code?

 

Any ideas?

Edited June 7, 2010 by markjw

[GeneralDisorder]

Sounds like a clogged catalytic converter to me. Run a vacuum test on it. Sounds like you have back-pressure on your exhaust.

 

Your compression numbers are fine. A little low but expected for an older EA. Nothing to be concerned about. My 260k mile hatch has three cylinders at about 140 to 145, and one (#3) that's at 110. You can't even tell when it's running. Idles smooth and has great power for it's age. Probably just valve seats.

 

Lots of things *could* be bad and not throw a code. You should run a d-check to be sure as it performs more complete diagnostics that way. EGR solenoid is not the cause if your power issue - that's just an emissions device and doesn't matter if it's working or not for proper running.

 

O2 sensor would only come into play in closed-loop operation. For the first 5 to 10 minutes upon start up it runs without the O2 sensor (not hot enough to activate it) and so the problem would dissapear durring that time if the O2 was to blame.

 

GD

Edited June 7, 2010 by GeneralDisorder

[ShawnW]

Do you have the hydraulic lifters quieted down and it runs pretty quiet now?

[markjw]

Do you have the hydraulic lifters quieted down and it runs pretty quiet now?

 

The engine runs quiet. It has since the rebuild. Before the rebuild,It ran quiet,but it had bad head gaskets.

 

The problem is fixed now. It has good power and runs smooth at crusing speed.

 

It could have been back pressure in the exhaust,or it could have been the o2 sensor. I installed a different y-pipe with a new o2 sensor. Runs like a top.

 

Thanks for the help..

[idosubaru]

interesting - swapping the front Y-pipe and O2 fixed the issue? interesting indeed.

 

late to the party but those compression numbers look fine. wouldn't surprise me that with a more ideal compression test the numbers would be closer, but like GD said looks fine even if they're accurate. battery, cables, throttle body not propped open, and your HLA's not being perfectly pumped up could all sway the numbers a bit.

[coxy]

Have a good look at the ignition secondary system coil onwards,when cruising the mixtures are leaner and with a weak ignition more prone to misfires,richer mixtures fire easier than lean mixtures so either lean miss or weak spark are most likely culprits.

Lean mixture can be air leaks,airflow meter settings on injected cars or carb issues on carb models or even caused by issues with carbon canisters for fuel tank breathers,they do not last forever and rarely get replaced or checked.

[GeneralDisorder]

The problem is fixed now. It has good power and runs smooth at crusing speed.

 

It could have been back pressure in the exhaust,or it could have been the o2 sensor. I installed a different y-pipe with a new o2 sensor. Runs like a top.

 

Thanks for the help..

 

Glad you got it fixed - sounds like the cat was clogged. If you get a chance you might cut it open and remove the converter matrix - you can always install an aftermarket converter in the mid-pipe and still use the y-pipe for another project if it's good. Would also be educational to see what the matrix looks like when it's clogged. They often just break apart and get jammed in the outlet of the converter causing a flow restriction so there might not even be anything useful left in it.

 

GD