It'll take a day or two to reconfigure my woodworking shop into an auto shop before I can get to the task, but I'll let you know how it turns out. The input from all is appreciated as I'm not much of a mechanic... ...just willing to learn on this diesel; gas trucks and cars have never interested me beyond getting from one place to another. You folks have given me the confidence to do it myself.

Tom

 

As a side note try to use a good pick to get the pieces from the threads before using the tap.......you may be able to clean it without excess labour.

 

What's a good pick? I have a set of those cheap made-in-India stainless dental picks. I only bent it when using it to get the chrome out of my teeth; glow plug threads, that is... Kinda shy about using a harder, more brittle pick, but if you know of one that has some good strength and is not brittle I'd love to know about it. My metallurgical knowledge is weak.

T

 

snapon. mac. matco. proto. all make good quality picks 4 in a set different shapes.
These are an asset to every toolo box many uses inexpensive.

 

Thanks to all for your guidance and support. I drilled out the hole with the bit just brushing the threads; that caused most of the remaining material to come out, some in chunks. Then ran a 10mm x 1.00 tap through to the shoulder. Did the vacuum and air thing to clear the chips through the injector hole and think it's clean. It runs just like before with lots of white smoke at start-up.

Telling thing was the injector. It was date stamped 9-89 proving to me that it was original equipment as is the injection pump. Further, the injector looked like someone left it out underneath a junker truck in the rain for a year or so. It had quite a bit of rust just below the threads, which were also a bit rusty. It was covered in what appeared to be diesel fuel, but with lots of dirty oil or soot as well.

I'm generally inclined regardless the outcome of the compression test to replace the injectors and injection pump, but have some concern that the better performing components may cause problems elsewhere; kinda like replacing the injectors but leaving a pump with 200,000 miles on it.

Thanks again to all.

T

 

The fact the injector was wet with fuel tells me the injector is leaking fuel into the cylinder after it is supposed to be closed.
The excess soot also says the same thing.

If the compression test comes out OK, it sounds like you need injectors.
In a perfect world where money is not such an issue, IP's and injectors would be replaced together.
That way you get the full benifit as far as power and economy go.

I also know this is not a perfect world.

 

as mentioned before all speciality tools should be bought through snap on, matco, mac or you risk this happening. same with building a engine and using a harbor freight torque wrench. is the money you saved really worth it in the end? another reason why most of the stuff produced from china is garbage and cheaply made.

 

I had to have a 2 3/4 socket the other day bought the 1" set from harbor freight took a helluva beating from impact ratchet is junk though.

 

Found the Matco guy this morning and have a new compression tester. The adapter seems to weigh at least twice what the Harbor Freight Chinese version did; probably actual steel in it. If I've got reasonable compression I'll replace the IP and injectors as one project. It's not a perfect world, but one has to try...

To his credit, the Harbor Freight guy gave me my money back even without a receipt.

T

 

This could have been a comedy of errors... ...but, I don't think it's funny no more...

The 'Matco' diesel compression test adapter crapped out on me after the first cylinder. I tested cylinder 1 and got 435psi; on cylinder 2, though, the gauge went up to 350 and slowly leaked to 0. Cylinders 4 and 6 did the same thing; so did 1 when I re-tested. So, it wasn't the engine. I called Matco and they referred me to Star Products for service on the thing. Star Products' products look an awful lot like the kits at Harbor Freight... Anyway, I opened up the Schrader valve to find that the spring is all bound up inside; it keeps the adapter from holding air pressure. At least this adapter is made of steel and didn't twist in two on me...

The folks at Star Products are going to send me a set of five adapters free of charge (they've gotta cost all of 13-cents) and I hope that at least one of them works...

China... ...it's everywhere...
Love the food and art - but they can keep the tools...

T

 

does the tool say matco on it.

 

My mama told me not to judge a book (or a tool set) by it's cover but sometimes I forget. Star Products is a U.S. company; not Chinese. They were apparently started in New York and recently purchased by A&E tools in Wisconsin. The diesel compression tester and adapter were both made here in the states. I hate to be wrong, but I really hate to publicly 'dis' somebody that doesn't deserve it and then keep quiet about it.

If anyone uses these tools, there is a problem that their technical staff helped me through. The Schrader valves can crap out when one releases the pressure in the gauge immediately after testing a cylinder. Apparently the pressure differential between the cylinder - immediately after the test, and before leak-down - and the gauge when the pressure suddenly goes to zero causes the spring to depart from its intended location. The engineer at A&E asked me to wait 30 seconds or more after the test before releasing pressure on the gauge; and it worked fine every time after that. They're going to look into modifying the pressure release valve to do it slowly, or to modify the user instructions to the updated procedure.

Sorry to have led anyone astray regarding these tools. They just use a bright red box that looks the same as the ones at Harbor Freight, and with a name like "Star" Products I figured China had to be in the picture. Learned my lesson - again - and I'll look closer next time.

By the way, this 17-year old engine has compression of 405, 410, 410, 420, 425, 425, 435, and 440. Time for an injection pump and injectors!

T

 

I realise this is an old thread but i just bought this tester, ran into the same problem with the fit, looked *closely* at the other adapters and found they are close, enough that you can start the first couple threads, but not exactly the same. The manual lists the one for the 6.9/7.3 as M10X1(M) which i assume is 10mm x 1mm. there is no other adapter in the kit listed with those specs. the short one that 'fits' was the #10 in my kit, listed as ZG1/8"(M). googling that shows a bunch of similar quick connect fittings (mostly chinese) so whatever they are, they don't seem to be meant for these engines.

that they're made of cheap metal could be a good thing. if you tried to stuff a good, hard steel fitting with the wrong threads into your head, you could have even worse problems than needing to clean it up.

my one question is, i found a couple other threads of people who also bought this HF tester and went ahead and cut the fat end off the 6.9 adapter, then said it worked fine but that end contains a schrader valve, as do all the adapters in the kit. is that valve necessary to get an accurate compression reading?

there's still a releif valve up near the bottom of the guage. the valve in the adapter couldn't do much more than assist by keeping pressure in the rubber hose. i guess if it's really important, one could adapt another schrader valve above the adapter.

thoughts appreciated.

 

Not sure if you read a thread by me somewhere else where I did this but yes, cutting the fattie off will make it fit and the valve is contained in it. I was planning on adapting a valve to the hose because the gauge was wonkers during testing. I'll give it another try tomorrow probably but I don't think there is a valve on my gauge

 

Well, i did it and that is the only valve in the line so it didn't work. with limited access to fittings, i managed to adapt one of the other adapters in-line, #6 in the kit (according to the manual: http://manuals.harborfreight.com/man...3999/93644.pdf) with another $10 worth of brass fittings from the hardware store.

an easier way would be if you could find another one of the mini quick couplers (dunno if HF carries these, i couldn't get back to the store and they don't list them online), then you could use just a single 1/8" pipe coupler by snapping the extra QC onto the #17, putting the 1/8" pipe couipler on that, screwing the #10 adapter (w/valve) into that and then you could snap the guage hose onto that.

if you have a turbo though, you won't be able to stuff all that under it at #7 cylinder. i prolly have to go back and replace one of the straight fittings with an elbow.

my compression checked out ok but guess which cylinder had the GP with the burnt off end? grrrr.....

good luck with yours. if you come up with any better or shorter solutions, lemme know. i still worry about that #7 cylinder.