How common are burnt valves?

[idi_Marty]

Ok, got some great advice in the 911 section, but I'm not really familiar with the 7.3 idi. How common is it to find a burnt valve? And how easy would it be to tell the difference between a burnt valve versus a dead injector? My diesel has a hard ticking sound under acceleration, and feels like it has lost power, from the drive home to now, it really feels like it is working hard to get to speed slowly, but will maintain speed easily, but the ticking is scary. It white smokes a little when it first starts up, but is done once start to drive. I have already talked to typ4 about a compressor wheel that I need, but trying to figure out what else I need, and for the life of me, someone please educate me what the sensor is on top of the ip is that the throttle arm rest against at idle and what is it's purpose for moving out and in?? Lol.


1994 Crew Cab F-350, 7.3L idi Turbo Diesel, 4x4, auto, DRW, Tollesboro, Ky

 

[Wyreth]

Very good place to come for answers about the IDI, I don't think there is anything the collective here doesn't know. Don't be afraid to ask anything, even if you think it's a dumb question, SOMEONE will have an answer and we're more than happy to share.

I've not really heard of too many valves burning, well not without something else happening first. A dead injector sounds a little more catastrophic than just a worrisome tick. Could be a loose/bad rocker, or worn valve guide. The white smoke could be oil burning off from a leaky/warn valve guide. Or you could just have a *******/leaky injector or two. Do you know how many miles are on your fuel system? The IP is only good for 100k or so, same for the injectors. It may be that it's time to make a truck payment.

That's not a sensor. That's your cold idle solenoid. Fun fact, it doesn't actually have enough umph to kick the throttle to high idle. So it's good practice to pump the throttle once while your glowplugs are running. That will allow it to set when it's cold.

 

[idi_Marty]

Thanks, yeah I figured after reading some of he articles that this was the place for the correct answers, so I joined lol. I pulled the driver side valve cover before I left for work and all the valves looked fine, I didn't roll the motor over to check each cylinders valves but they sat level, and all at the same height, and the pushrods that weren't under load would spin without wobble, I figure the stem seals could probably use a look at, in regards to the smoke, and I'm not sure on the fuel systems mileage, that's probably where I should look next, I read about cracking the lines and I figure ill do that the next chance I get, what's the best way to inspect the ip's line pressure? Yeah I wouldn't mind just rebuilding it ground up, if I could find a kit for the ip, and a decent rering kit. I'm not to scared of the ip, I have the manual for its guts and a buddy with the tools. That's good to know its rare to hear of a burnt valve, also is there anywhere that you can buy parts for the injectors? Oh, I used a automotive stethoscope to try and isolate the ticking, it seems that it is loudest from the #3 cylinder on the head, that's why I was under the impression of a burnt valve.


1994 Crew Cab F-350, 7.3L idi Turbo Diesel, 4x4, auto, DRW, Tollesboro, Ky

 

[79jasper]

You aren't talking about rebuilding the IP are you?

I ask since you said a "kit."

 

[idi_Marty]

Yes I am talking about rebuilding the ip, my friend has a machine shop and the tools to do it. That's the same response my wife gave me when I rebuilt my last trucks tranny lol, I'm an American, yes we can lol


1994 Crew Cab F-350, 7.3L idi Turbo Diesel, 4x4, auto, DRW, Tollesboro, Ky

 

[79jasper]

I feel ya on the can do attitude, but ip's to tranny's is apples to peanuts.....

 

[gatorman21218]

OK to isolate a bad injector you undo one fuel line at a time. If the tick goes away then you've found the winner. To find a bad valve you need to do a compression test. Riotwarrior has a great thread going about compression testing and valve testing. I had a exhaust valve go bad and I rebuilt at 295k.

Trust me I do stuff myself all the time. If I don't know how then I learn and buy the tools. But don't mess with the IP. If you need one rebuilt then have Agnem do it. There are a thousand parts and each one must be calibrated. There is no way you can do it yourself plain and simple.

 

[Mulochico]

x2^^^^^^

 

[riotwarrior]

First Welcome to OB you'll find a friendly group and about the best info on these trucks you can find anywhere.

Take a look in the TECH section and the FAQ section and HALL OF SHAME...u don't want to spend money with some of the vendors there that's for sure!!!

Now onto what I've got...

Ok, got some great advice in the 911 section, but I'm not really familiar with the 7.3 idi. How common is it to find a burnt valve? And how easy would it be to tell the difference between a burnt valve versus a dead injector?

K sounds like from what I have read that you have a few potential problems.

Turbo is one, that's being taken care of for sure with Typ4 Russ he will most definitely help you out and get you going. Talk to him about a cam while at it!

As for the IP Please, don't think it's just a kit and a rebuild anything remote like a carb. It isn't, it's something that requires $$$$$pendy equipment to test, and calibrate. Mel as said will take care of you there. Also IIRC there was a Baby Moose in the Market Place here for sale...but I don't know if it is still.

Burnt valves are not something I have personally hear a lot of with these engines. However they are quite well known for wearing out valve guides, don't ask how I know

I'd personally recommend a compression test of the engine. This will give you some inclination as to condition and a leak down would be best.

My diesel has a hard ticking sound under acceleration, and feels like it has lost power, from the drive home to now, it really feels like it is working hard to get to speed slowly, but will maintain speed easily, but the ticking is scary. It white smokes a little when it first starts up, but is done once start to drive. I have already talked to typ4 about a compressor wheel that I need, but trying to figure out what else I need, and for the life of me, someone please educate me what the sensor is on top of the ip is that the throttle arm rest against at idle and what is it's purpose for moving out and in?? Lol.


1994 Crew Cab F-350, 7.3L idi Turbo Diesel, 4x4, auto, DRW, Tollesboro, Ky

Smoking on start up could be an injector popping before it should and is unburned fuel passing through as well a sticking injector could cause this. Mel or Russ can help out with some good BB injectors if you like.

Getting them POP tested would be fantastic idea to help get an idea if they are balanced and letting off at the correct pressure.

The large plunger on the passengers side of IP is cold IDLE solenoid just increases the idle speed when cold. The flat spade on top of IP at rear towards windshield is cold advance and the other flat spade connector towards front near fan side is the FUEL STOP SOLENOID or FSS for short.

Again Welcome TO OB

Al

 

[Wyreth]

An IP, is not simply a mechanical device. It is a mechanical computer. When you disassemble it, you wipe its "operating system" clean. So unless you know how to re-program it, and have the testing gear to tune it (calibration bench) it my be perfectly assembled... but it's not going to work.

Seriously, send it to a rebuilder. DO NOT try it on your own, unless you have access to a cleanroom ,a calibration bench, and the knowhow to use them. A simple manual will do nothing for you there.

Also look at this thread, this is what I'm talking about with warn valve guides. This is a common problem with these engines at higher mileage.
http://www.oilburners.net/forums/showthread.php?65252-TECH-101-engine-chuff-valve-breaks-POST-MORTEM

 

[idi_Marty]

Thank you, thank you , thank you, seriously I really appreciate all the great information you all are providing me with. I am a truck driver by trade and have 6 loads to haul out of my way this weekend before I will be able to dig into my truck, but I have the start of a great battle plan, I'll start with the injector lines, then move into the compression test, I'll take a look in the market place, and this week looks like it will be a great paycheck come Friday, so I'll probably be looking forward to new injectors as long as nothing unexpected comes out of the wood work... Like bill collectors can smell money or something lol. Oh and ive seen mention of a type 4 camshaft on a couple threads, could you elaborate on the inferiority of the stock camshaft please? I'm not really looking for any power, just dependability, got the truck for a workhorse on the farm, don't get me wrong, she's my new baby, but I'm only after making her a solid cattle hauler, and baby hauler.


1994 Crew Cab F-350, 7.3L idi Turbo Diesel, 4x4, auto, DRW, Tollesboro, Ky

 

[icanfixall]

No matter what shop and tools your friend has to rebuild an injection pump requires a claibration bench and they cost around $75,000.oo used. Knowing how to use one takes lots of factory training. I aplaud your American want to attitude but thses are small fuel metering items and there are about 75 gaskets and o rings in this small pump. I'm a smart guy so some say but I will never take apart an injection pump much farther that the fuel delievery valve. Much deeper and you have some calibration isses. Find the bad cylinder by cracking open the hard line nuts on a running engine one at a time. Then remove the cylinder injecter on that one and place it in another location. See ij the miss follows. Do you know how many miles are on the injecters and injection pump. They usually last around 125,000 miles. Typ4 knows his stuff and your lucky to be able to talk with him. Hes a busy guy doing all kinds of stuff. Hes exelant with turbos too. Mel aka agnem owns Conestogas Diesel Injection and is by far the best place for injection pumps. Buying from any other ebay seller is making a huge mistake. Cheap pumps are just that. You end up paying twice for the pump but feel stupid doning it. Its a costly learning experiance done by many here but at least we do learn. The Hall of shame is there to help member learn without costing them dearly.

 

[idi_Marty]

You must be registered for see images attach

I guess the previous owner was using the turbo in his spare time as a corn grinder..... Ordering a replacement when paycheck comes in


1994 Crew Cab F-350, 7.3L idi Turbo Diesel, 4x4, auto, DRW, Tollesboro, Ky

 

[idi_Marty]

Well... I have an instant synopsis of the problem... Makes a great way to start my work day... as I cracked the fuel lines one by one... I knew that my old fuel filter had a terrible amount of crud in the water bowl, BUT what I did not see was the rust colored fuel that came out of the fuel lines just now, I'm guessing that the fuel tank is nasty! So my next day off is going to include dropping a fuel tank that is 3/4 full.... $h!t... I'm figuring new ip, new injectors, and new tank, and blowing the fuel lines out, hopefully this rust hasn't caused any internal damage... What do you all think?


1994 Crew Cab F-350, 7.3L idi Turbo Diesel, 4x4, auto, DRW, Tollesboro, Ky

 

[idi_Marty]

You must be registered for see images

here's a pic of the fuel on the cap and injector... Pretty sure that will make a motor unhappy...


1994 Crew Cab F-350, 7.3L idi Turbo Diesel, 4x4, auto, DRW, Tollesboro, Ky