I saw thoose parts, i just want to know if they work out good. I kinda gave up lookin a while ago, but still want one. The guage has a pressure relief valve, but there is no check valve on the guage for incomeing pressure from the engine, all compression guages are like that, well any i have used. The check valve wich looks like the valve in a tires valve stem, is always mounted in the piece you put in the engine, like your spark plug adaptor or injector adaptor. I have a used a snap on compression tester on a ford 6.0 and I do think its worth the money, when it comes to a tool that i use to see if an engine is blown or has a major failure i always buy snap on, so I know i'm not getting tricked when i use the tool. OR possible MAC I like both.

 

The one we borrowed from Chris when diagnosing Luke's truck had a check valve and a relief valve on it. If it doesn't have a check valve, the gauge is worthless, especially if working by yourself. I thought the one Chris had was Mac, maybe Luke will remember.

 

I borrowed that kit from Paul actually.........it for sure had a check in the guage. I just used Jays snapon guage on a 22r toyota engine at his shop a few weeks back. it has a check and relief too. all the bells and whistles are in the guage not the adapters.


Princess Auto stuff has its place.......and its no where near testing and measuring tools.

 

If you're chatting with your strap-on guy on Friday, mind finding a price on a timing light for me? Rob has a Mac one that has the **** to add advance so you don't need timing tape. Slick as ****, and you only need one mark on the balancer. I'd like to get one with that feature. Then I have a nice complete timing set.

 

I searched thou the CR manual on the Quickserve, cant find any info about comp tests, all they care about is blow by. I going to look some more, or phone the tech center.

 

my 12v was 400 +/-10psi across the board.

 

I can't find any info from Cummins on Common rail compression test specs either. Some folks say that Cummins doesn't have any specs & doesn't even encourage compression testing.

All I have to go on are results from other folks, which is about 400-450 PSI on a good running Common rail.


Which brings up the next question... What is the best way to disable the CR high pressure fuel system to do the compression test?
I plan to remove all the injectors at once, so the engine will spin easy.

1. Crank the engine over with a remote starter switch but the ignition key still off? The lift pump would not run, none of the electronics would be enabled in the CP3.

2. Unplug the lift pump, drain the fuel filter cannister & crank the engine over with the key? When my lift pump died a few years ago, the engine was getting zero fuel.

 

When we were messing with Kev's truck after its major surgery, tried to fire it up, but wasn't getting any fuel. Would crank to beat hell. Turned out that a plug from the positive cable to the ECM was disconnected. You could do that, or look for a fuse. Something about running the CP3 dry doesn't sit well with me, even if it is only a short time. I don't think that will trigger the lift pump, but better find out before pulling injectors. I know on my truck, the lift pump dumped a ton of fuel through the head and out #6 connection where I forgot to install the connector tube.