cleaning injectors?

[cotto]

Hey guys,

My mileage is in the cellar. My '93 has just turned 180,000 mi and it's competing with my parent's 1975 six pack long bed with the 360 V8. Not that bad just yet. K & N Air filter's clean. Fuel filter's clean. I've never played with the pump. I've run quite a few bottles of Howes fuel ad. I'm looking for something simple. Here's a lameo question. I know injectors get crud in them, so I was wondering if I can pull them and clean them, kinda like spark plugs? Is it possible? Will it help? Will I not see the results I'm looking for and it's just not worth my time? I don't really have the cash to throw at new injectors (I've spent it all on fuel) so I would like to put that off as long as possible. I searched the archives and came up with nothing so I thought I would throw this to the wisdom of the TDR.



Thanks for your time.

 

[cerberusiam]

I don't think just cleaning them will solve your problem. Generally dirty injectors will cause rough running and misfires. You didn't say if there were any idle problems or engine roughness so assuming only the mpg has dropped. The pop pressures are probably below specs and can cause mpg to go away. A couple of threads here suggested every 100k having the injectors pop tested and reset for best results. Mine are in about the same condition. Started right after the pump quit. I suspect with full pressure they are not holding well. Sure runs better than before but mpg is in the basement. You can have them cleaned and pop pressures set and it should be cheaper than new injectors. Good luck.

 

[JLEONARD]

I used to clean the injectors in my 81 VW. They always had crap in them.

Don't know if the same applies to our Cummins, but it used to be easy to do on the VW, and made a slight difference in performance... . especially in starting.

Jay

(the one who call his kids "critters". . you're too much Bushman)

 

[dpuckett]

cotto,

YEs, I agree; cleaning the injectors will hlep you get your mpgs back, BUT, it wont do any good to take them out and clean off the tips. I just had mine tested, (out for head gasket replacement) and they made a good spray with the tips all carboned up. They need to be disassembled to clean them thoroughly, and like cerbrusiam said, the pop pressures will wreak havoc on you rmileage. But if the tips are clogged, it may cause them to just smoke. I've had them make smoke, run and idle smooth, be spraying out 3 or 4 of 6 holes. Had a rough idle, and the injectors were all in spec. I have my own theories on the latter, but wont delve into it now. Find an authorized (certified?) BOSCH shop to pop test the injectors for you. Most places will do it free, if you bring them in. THey come out similar to spark plugs, but are a hair more involved. Make sure you loosen the lines from the pump and the hold down clamp doo-hickies (yes, it IS a word, I spelled it, didnt I?). Spray liberal amounts of PB Blaster on the nuts after you get the return line and injector lines off the tops. After removing the nuts, spray some of the oil into the bore to loosen up the injector from the head. After 255K, I had a few that I had to give a real cussing before they decided to break loose and come on out. Though I wouldnt highly recommend it, I have grabbed the injector with a set of 10" Vise Grips right below the threads and GENTLY pry/ wiggle back and forth for 3-5 minutes, and they eventually come out. Other guys have devised a slide hammer of a sort with a long bolt ans two nuts welded together, or something to that effect.

Also, have you checked the timing? Retarded timing will also be accompanied by (though not laways) smoke- bluish/white @idle. or black on hard acceleration, and be kind of sluggish. Pump may be getting weak. Still got power? or is that slipping, too? If you have power, I'd say most likely pop pressures. Only way to tell about that is to get them tested. Mine were popping at 3200-3225. Pretty close to stock spec for 255K, IMHO. I know of a shop here in the swamp that does pretty good work for a decent price. PM me if you're interested.

Daniel