Hi everyone.

This is my first post, but I've been obsorbing info from this board for a few months now. Thanks for all the help.

I recently purchased a 1985 740 turbodiesel with about 140k miles. It's the first diesel I've ever owned and the first car I have really enjoyed driving.

I understand that the 740 D24T has Bosch injectors. I would like to clean the injectors, but I'm not sure what injector seal kit to buy.

At Ipdusa.com the kits are for B230f engines and LH Jetronic injectors.

FCPgroton.com has Bosch kits but for B230FT engines.
http://www.fcpgroton.com/fuel700900/volvo740b230ft.htm

Is there a difference between gas and diesel injectors?

Also, will I be able to clean the injectors well enough by myself, or should I take them to a shop? I found this one nearby me that will clean and test them for $45 (in case it is useful to anyone):

Diesel Fuel Injection Service
9331 South Broadway, Saint Louis, MO 63125
Contact Info: (314) 631-2500
http://www.dieselfuelinjectionservice.com/

Thanks

Thanks for all the suggestions.

A little of the Diesel Klean stuff has been added with each tank for a few months. I wasn't very confident about how effective it is. Last week was the first time I put some ATF in there.

I also have loosened the cap nuts before and found that a couple of the injectors did not effect the engine much. That is what got me thinking that I needed to get them serviced (along with the rough idle and 30mpg fuel mileage).

I will do the paper check for tube leaks.

I guess I'll give it some more time with the ATF and other cleaner in there and then try the nut test again.

If I do decide to try to clean the injectors myself, where can I get the heat shields?

Unless you can pinpoint problem and blame it on a diesel injector, don't "clean" it. The aluminum head can be damaged by removing or replacing an injector, because of the dissimilar metals and large thread. Also, the 6 high pressure lines are brittle and easily cracked. 140k miles on an injector is not much. Look for trouble but don't make trouble. 1)Check to see a good flow at the final small return hose to the pump fitting from the injectors. 2)Engine running,hold a clean bright white piece of paper along each injector tube; if the tube leaks, the diesel vapor will discolor the paper. If the line leaks, impossible to fix, you must buy new or good used before testing injector on that line. 3)With engine running, check each injector in turn by loosening its tubing cap nut just enough to release diesel at the nut; note if this makes a difference in engine running. If loosening nut makes no difference then that injector probably needs attention; retighten nut go on to next. If there is difference in engine running, that injector is probably good, retighten nut. Do this simple 20 minute procedure every 5k-10k miles.

Best advice is to leave the injectors alone unless you have the equipment to actually test and set them up correctly. These are precision devices and dont take kindly to even common room dust. Send them in if you must but don't take them apart.



988

The injectors on your diesel have no seals like you are thinking of them. They have metal heat shields that they thread down onto and they are not supposed to be reused. As far as cleaning them goes there are a couple of different avenues; back in the day of the diesels we always simply took them out and ran them through the hand pumped injector cleaner. Mind you this thing develops enough pressure to open a diesel injector so if you put your finger on the tip of it when this is going on it will inject fuel right into your skin, bad idea! Several years back I bought a 240 diesel for one of my kids and I no longer had access to the injector cleaner. As it turns out you can unscrew those babies and take a wire brush to just about every part on them. They are built like a tank inside and seeing as how they are mechanical by nature it is really just a spring, plunger, a shims inside. I would take them apart one at a time, clean them up, and reinstall them with new sheilds and be done with it. Has anyone told you about using ATF in the fuel yet? It does work. It will raise the cetane level of your fuel. In case you do not know, cetane is the fuels ability to ignite under compression (which is how your diesel ignites it's fuel). So if you raise it up a few points it will tend to ignite a little later and not detonate as bad. It is the opposite of octane, which is a fuel's ability to resist ignition when compressed. That is why fuel with lower octane tends to ping, because it is lighting off early due to compression and heat rather than from the spark plug. Anyhow, hope this answers your question.

Yes octane and cetane trends are the opposite - higher octane gasoline is more difficult to ignite (hence less detonation/pinging) - higher cetane Diesel fuel is easier to ignite, not harder to ignite as your post says. Refer to http://www.buyduralt.com/cetane.html for more details. There are several Diesel fuel additives available to aid cold starting and provide better lubrication for the pump.

Zack
1980 245DL M46 274k
1985 744TD M46 250k
1988 745T+ M46 201k

Dear greengenes,

Good p.m. and hope this finds you well. Contact Nick Bauer at fcpgroton. He's hugely knowledgeable. He'll make sure you get the right parts.

I do not know about cleaning diesel injections. The Board has many experts, including Volvo Mastetechs. They should be able to answer this question.

Yours faithfully,

spook