Sorry for throwing a non-truck problem here but it's tool related problem.

I currently deal with miss/hesitation on '99 Crown Vic, 4.6L V8 engine. I am down to compression test but a stupid problem occured.

I have this exact compression tester, nicely packed in the molded case:
http://www.harborfreight.com/cpi/ct...temnumber=92720

It seems that there is no adapter needed for my car - fitting on end of the hose matches the spark plug size (picture show adapter that screws off and shows the right size fitting).

The problem is (might some stupid for someone) that it seems to be impossible to thread the damn hose with fitting down. Hose is permanently banana shaped (as it fits the case this way) which keeps the fitting itself from evenly threading down. And the plug hole is pretty deep.

There is also a rubber cone attachment but it's kinda short and leaves not too much space for gauge itself.

Any advice here?

 

This is what you have.

http://www.harborfreight.com/cpi/cta...emnumber=92720

Does the other end of that metal tube (part with the rubber cone) fit into the end of the hose (attached to the tester)?

Also, some people don't like that kinda of tester where you have to hold the rubber cone in the spark plug opening. Can be inacurate.

Can you acquire a tester that threads into the spark plug hole?

 

1. Tube with rubber cone has a quick connect on other end that can be attached to gauge only (not to the hose) and since there is not enough clearance for gauge (fuel rail, ect), it's basically useless. Plus, as You said, rubber cone is not a good way to have things measured. Pressure is way to high and it's extremely inconvenient to hold it there.

2. Looking at the hose, on one end it has quick connect that attaches to the gauge and on the other end it has threads to thread into the spark plug hole (there is also an attachment that can be used over these threads for bigger size spark plugs - this adapter is shown on the picture).

I have chosen this particular tester because hose threads fit directly into the plug hole (I knew that if there was additional adapter required, it could be easily unscrewed inside the plug hole... and I would be screwed then )

Problem is that hose cannot be held down at right angle to screw it in. It is banana shaped and flexed when I tried to press it firmer down.

I am pretty sure there is some way to thread it in. Either by holding in some particular way, maybe taping it with duck tape (to make it thicker and tighter against plug walls) or using some kind of tube extension (like cone tube, but with male threads on one end and female threads/qc on other.

http://www.toolsource.com/ost/produc...MFFBPF0UVBE9N4
http://www.toolsource.com/OstImages/...ages/94518.jpg

http://www.toolsource.com/ost/produc...MFFBPF0UVBE9N4
http://www.toolsource.com/OstImages/...ages/96440.jpg

I wish I had one of these extensions but I can't imagine there is no other way of using regular compression tester without it. C'mon folks!

 

Sounds like you're saying that the hose is oval shaped.

Like you said, maybe tape up the hose to make it stiffer.

Maybe an extension, but that's extra $$$$$. and will it work for sure.

Other than that, don't know what else to say.

If you get it to work, post it.

Good luck.

 

I made an extension for mine from air hose parts (seach here), though you can buy 6" extensions from Northern Tools too. I could not make mine work with a Taurus or my FE 390 so I made an adapter.

 

Weird, isn't it

I know it's not just my problem, but SOHC and DOHC problem.

And regarding taping... I thought about taping the hose in 2 places
- close to thee bottom of the hole
- close to the top of the hole

I hope that this way it will run straight at least in the hole.

I doubt if making it stiff (or straight) at the whole length could work. Because it's pretty long, it has to be flexible to some point. Otherwise (because of fuel rail and other obstacles) I just couldn't screw it in.

Holding it tight in my hands, I can rotate it just 1/2 of a turn. To go further, it has to flex and there - it is not flush with the spark plug hole anymore.

I will be taclking it tomorrow and I promise to post how it goes

 

CVTom, cool.

I got an old (20+ years?) Craftsman comp tester that has just one fitting on it, but it's threaded for both 14 and 18 mm plug openings.

Not sure how it would work on todays cars; so damn crowded in the engine compartment.

 

try a coat hanger inside the hose to stiffen it. it should take out some of the bend and let you get it threaded.

 

Try a short peice of rubber hose with an inner diameter large enough to fit over the tester hose 3-6 inches. split it lenghtwise and slip it over the tester hose you should be able to hold the "cover hose" and turn the tester hose. This trick works on those deep socketed "ricer " type motors.

 

Mine's kinda like that, with the quick coupler at the gauge. I have an easier time of it if I unhook the gauge when installing the hose.

With the o-ring, it doesn't have to be that tight to work. Maybe you can remove the brass fitting, screw that in, then attach hose and gauge.

-Smoky

 

Got it figured out and here is how it went.

While still having old compression tester...
http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=92720

... I wanted to make hose stiffer so I got 6in of 1/2id PVC pipe, cut it along and got it around the hose and around the fitting. It didn't help at all. And it was much harder to get off the hose than to put it in

I thought that there has to be something wrong with the fitting itself. Threads on the hose fitting were obviously not even touching the spark plug threads (it could be because there was small "shaft" past the threads).

There were 2 or 3 different models in Harbor Freight so I gave them a look. The cheapest one looked like it should work.
http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=92697

It's hose fitting was good for 2 plug hole sizes (14mm and 18mm, 2 seals too) and it had no unnecessary "shaft". This kit also included nicely threaded adapter (14mm, as on picture).

Now the weird part. I tried the new kit on my '92 P74 and it worked great, with adapter or without. On the other hand, it worked on '99 P71 with adapter only!

I taped the hose just by it's fitting thick enough to snug it into the plug hole. Then I screwed the adapter and taped it together with the hose. It looks like this now:




This model doesn't have a molded case but it nicely fits together with oil pressure tester in it's big case.

Thanks for help everyone!

 

not sure that we really helped, but glad it worked out nonetheless.