What is good compression pressure? And more??

[php]

I tested the compression on my 93, V6, 3.2L last night and had 155psi on cylinder #3 and around 180psi on all the others. This falls within the 25% range, but are good numbers for this engine?

What is the proper compression psi for this engine?

Why are you supposed to test your compression with the throttle wide open?

Just to note, test was done while engine was cold. It's running so bad, I didn't want to really mess something up trying to get it warmed up.

How would this affect the test?

I'm really going crazy trying to solve this problem. I have replaced the timing belt, catalytic converter, ignition control module, plugs, wires, crank position sensor, MAP sensor, and O2 sensor. I ohmed each coil out and they tested okay. I've listed to the injectors and they sound okay. I tested the vacuum at the MAP sensor hose and was getting 20" of vacuum at idle, so I don't think I have a IMG problem.

A couple of suggestions thrown at me: bad alternator, fuel pump/fuel filter, ignition coils. Where should I start first?

[Canucklehead]

Originally Posted by php

A couple of suggestions thrown at me: bad alternator, fuel pump/fuel filter, ignition coils. Where should I start first?

Fuel filter -> cheapest and easiest.

[Ramblin Fever]

Timing belt tensioner??

[php]

I'm gonna replace the fuel filter and check the fuel pressure first. If everything checks out there, then I guess I'll tear the front of the engine apart again to see if the timing jumped. However, wouldn't my compression pressure really suck if the timing was off?

[php]

Well, I replaced the fuel filter and checked the fuel pump pressure (40 psi). Still have the same problems. So now, I'm in the process of changing the fuel injectors. Is there anyway to check them to see if the injector are good?

[Ramblin Fever]

You mentioned already having done the timing belt, did you do the tensioner at the same time?

I have no idea how horrible it would run if timing jumps, but I do know those tensioners usually fail MUCH more frequently then the belt. And they say if you put a new belt on without replacing the tensioner that they will most certainly go.

Just throwing out ideas, though.

[php]

Originally Posted by Ramblin Fever

You mentioned already having done the timing belt, did you do the tensioner at the same time?

I have no idea how horrible it would run if timing jumps, but I do know those tensioners usually fail MUCH more frequently then the belt. And they say if you put a new belt on without replacing the tensioner that they will most certainly go.

Just throwing out ideas, though.

No, I haven't replaced the tensioner yet. I had to order it and I really couldn't wait for it. But, as I mentioned in previous post, if my timing belt slipped, wouldn't I get poor compression? Will probably replace tensioner soon, as I'm now waiting for fuel injectors and Rodeo is basically undriveable.