Poor MPG's and leaky Injectors

[SAronson]

I just degreased the engine and adjusted the valves yesterday. Now today, I should have a clean motor but I noticed some fuel around the #1,2, and 3 injectors. They seem to be seeping at the base of the injectors. Is it time to pull the injectors and have them reconditioned, or can I simply retorque them to stop the seepage? What effect does the seepage have on the injectors?



As for poor MPG, I have had this truck for about 2 months now, and I initially was getting 17mpg. Now my mpg is at 14.



Things I've done since getting the truck:



-replaced fuel filter (Baldwin)

-changed the oil/ filter (Delo 400/ K&N)

-checked the K&N (clean)

-Adjusted valves (All exhaust were loose/ 2 loose intakes)



Truck specs:

'91 W250/ Banks IC, exhaust, intake housing/ H1C turbo w/wastegate (max boost @16) / 3. 07 gears & 33" tires



The truck seems to idle and run smooth, and the power seems to be O. K. . It starts on the first click with just a puff of smoke. I was going to bump the pump 1/8" and make the recommended adjustments, but I want to make sure the injectors are doing their job correctly before making any changes. Oh yeah, this truck was non IC prior to the Banks set-up.



Thanks for any help

 

[Greenleaf]

Welcome,

The fuel seeping next to injectors may not be fuel . It's possible to be oil from a valve cover thats setting down there in the bore. They can leak fuel. However it would most likely result in a slight miss or stumble. I say most likely.



To re torque will do little. This nut only secures the injector in the bore. There is a seal washer in the base of the bore to seal the injector to combustion chamber.



If injectors have never been serviced it's a good idea to do so. I would replace them/upgrade them.



Scott

 

[bgilbert]

SA, on the leaky injectors-> when I got my 91 it had two or three leaky injectors and when I removed them they weren't very tight, so I figured thats all it was, after torqueing them to the correct spec, I think 44ftlbs, they no longer leak. Yes leaky injectors will affect MPG's

Most of us TDR members are not fans of K&N air filters and definitely not K&N OIL FILTERS. Though they may be fine for you.

On advancing the timing. -> Our non-intercooled trucks came from the factory already with advanced timing. 1. 40mm vs 1. 25mm. I'd leave it alone. The 1/8 rules doesnt apply to non-ic engines. I bumped mine up maybe 1/16" and it was too advanced. I'm probly back to stock position or maybe 1/32" if any. And if you are running stock injectors, there's really no need to advance your timing beyond 1. 40mm where you are at now.

One last note on MPG's-> basically you can control this with your right foot. The more you hammer on it from a stop light, race the gassers, PSD's, the poorer your mpg's are gonna be...

Oh yeah, WELCOME TO THE TDR, and more importantly this 1st generation forum, the best on this site...

 

[Paychk]

if your injectors are loose in the bore, the only way to get them to seal right is to pull them out, clean the bore, and put new sealing washers in. The bores get full of crud when the compression leaks past & you have to get it out, to have any hope of sealing the injector.

 

[SAronson]

Re: K&N's..... I was afraid they were'nt right.



Re: Injector seals... . I'll keep an eye on the seepage, and if it gets worse then I'll pull'em.



Re: Timing... . I just got in from advancing it just under an 1/8". I guess I'll go set it back. The front cover does say it should be at 1. 4mm, but I read somewhere here that as the pumps age they become slightly retarded from there original setting. True / False?



On a side note, I just pulled the AFC diaphram and the cone is covered in brown goop/ cake. The Pin under the diaphram slides back and forth, but it seems a bit sticky. How do I clean out this mess?

 

[SAronson]

I just got back in from setting the timing back to stock. Also, I turned the fuel screw in 1 turn, and the starwheel in 2 turns. Of course the idle is too high now. That Idle screw is working my patience! What a pain it is to try and get a screwdriver on there.



Also, I cleaned the AFC cone/ pin/ & bore out, and coated it all with some silicone grease. As soon as I get the idle down I'm taking it for a test drive.

 

[dpuckett]

Um..... You got a pyrometer on that thing? If not, you may be in for a surprise. with my slight modifications, I can sitll get toasty, and I have the AFC pretty tight.



Goop, crud is normal in the AFC housing- it is a sign it had been lubed sometime in the past.



Fuel and oil filters- I run only Wix or Fleetguard (or Baldwin if I cant find the other tow). The K&N air filters aint worth the ink the labels on the boxes are printed wiht. See my post a month or so ago about the dirt they let in. I have a used baby BHAF (thanks ECJay) on mine to at least filter that air, even if I sacrifice a little flow. Good move on the oil, though. Get at least a CH-4/SJ, preferrably a CI-4/Sl rated oil.



Daniel

 

[SAronson]

Yep, I've got a Pyro and boost gauge. On the test drive last night I noticed improved acceleration and faster spoolup. It used to be pretty flat on accel until I goosed it, but now it is much more responsive. The EGT's increased too, but not bad. I have yet to pull a long hill to see how high they will go. No smoke at idle, but a noticeable amount during application of heavy right foot.



In regards to the K&N... ... . I installed one only because the prior owner was running one... . and he was a manager of a LUBE SHOP! Oh well, I guess I'll ditch the K&N since I've got a WIX out in the garage on the shelf... . thanks for the heads up!



How do I go about putting a TACH on this diesel thingy? I've only owned 1 diesel in the past, so I'm still learning a lot. The last diesel was also an inline 6 turbo..... an SD33 Nissan in a Scout. Now there was a motor I could get 24mpg's with! I now of a guy here in town that stuffed a Cummins in place of his SD33 powered Scout..... OOps I started to ramble about Scouts. It's just a virus of mine.



I was'nt aware that the Delo 400 came in different classifications. I guess I'd better check to see what I'm feeding my motor.



Regarding goop/ crud in the housing..... I also found some black tar balls on top of the AFC diaphram and what appeared to be a little oxidation (red/ rust). How would that crud get in there?



One more question for those who are still awake..... The banjo bolt/ air line going to the AFC moves easily (pivots) with the banjo bolt removed of course. Should this line move so freely? Is it possible that it could be leaking air/ pressure, and therefore not letting the AFC cone move as it should?



Thanks to all for the help. I'm very stoked that I found this site!



Steve

 

[Jdonoghue]

AFC air line

I think the air line is attached in the fitting with a rubber piece - it will move inside the fitting some. If you take it apart you'll see what I'm talking about. At least mine was this way.

 

[SAronson]

Just checked the Delo... it's a CI-4/ CH4-SL... 10w40

 

[Greenleaf]

Yes, the AFC air tube will pivot. However don't stress it any more than you have to. I loosen the little brass fitting that holds the "o" ring a few turns, then pivot it out of the way.



Hold you'r tongue the right way too and recite the following... ... "Oh,... ... Honorable VE". "I entrust my power to thee" "For I have labored upon thy controls, and ask, 'er akseth thou shalt not fail me".



You may wish to throw a pint of #2 over your shoulder too. Couldn't hurt.







Fellow Parishioner,

-S

 

[bgilbert]

I run Delo, but is that 10-40 a synthetic? I've never seen that, only 15-40, not to say that 10-40 is bad, probly just fine.

To check for leaks in the system, get a spray bottle with soapy water and spray all connections and throttle up the engine and look for air bubbles.

 

[JLEONARD]

Steve,

First... I run a K&N and have no issues... I think it depends on how well it happens to seal, and your driving environment.

Second... I have an Isspro tach that runs off the alternator. This is one type that will work in the pre-intercooled trucks... before the tach harness was standard.

To do this you will have to remove the rear cover to the alt and hook a small dia wire to one of the rectifier leads to get the signal. Then you will have to calibrate the tach with a hand held optical tach.

If you decide to go this way PM me and I'll help you with it.

Hope this helps.

Jay

 

[dpuckett]

DIS also has a set up for the tachs that includes the magnetic sender and wiring for nonIC trucks. Irony is, I have an ISSPRO tach, and keep saying I'm gonna pony up the $30 to get the adaptor kit, but have yet to do so. Maybe after a few good paychecks... Need to get my manifold and head worked on... .



Here's the web address- www.dieselpage.com Sorry, my ultimate list of P/Ns isnt in front of me, or I'd post it, too. HAfta find that before I leave, too.



Daniel

 

[BushWakr - RIP]

:-laf :-laf... ... Oh,... ... Honorable VE". "I entrust my power to thee" "For I have labored upon thy controls, and ask, 'er akseth thou shalt not fail me". . You may wish to throw a pint of #2 over your shoulder too. Couldn't hurt. ... . :-laf :-laf



Yer killin me here Scott..... I see you been paying attention in

"caclekism" school huh !!



pb...

 

[SAronson]

Originally posted by bgilbert

I run Delo, but is that 10-40 a synthetic? I've never seen that, only 15-40,



Ahh, so sorry... it is 15-40. The short term memory failed me.



Re: Tach... . Thanks for the responses, but that ISSPRO is a tad bit more than I wanted to spend on a Tach. Is there something simple I could hook up just to set the idle speed?



Re: Injectors... It looks like it was some old oil sitting down there, and they don't appear to be leaking. I would like to have them serviced though. Can anyone recommend a shop in my areae? I'm in Santa Cruz, Ca. . When I had my diesel scout, I had my injectors serviced by Coast Fuel Injection in Salinas. I think it was @ $240 for six injector service w/ new tips.



Steve