Injector replacement done

[Madurski]

I just replaced my old (290K miles) injectors with some 190 HP rated ones from PDR.



Not too bad of a job. I did have to fabricate a shorter slide hammer to get the back 2 injectors out but they all came out without much trouble. They really were ugly looking. Lots of black soot on them and the holes were hard to find before I wiped them off. I had been spraying around the holes with penetrating oil for a couple of days which may have helped to get them out easier.



Seat of the pants says it has slightly more power. It is a little bit louder at idle than before. It may be running cooler too, but the outside temps are a lot lower now than they have been recently. It remains to be seen if my mileage improves. I was down to around 14-15 MPG :-(



Someone mentioned before that they were interested in the old injectors. Let me know what they are worth to you and we'll work something out.



Later,



Ron Madurski

 

[GMichaels]

injectors

would like to know if your milage improves and what other benifits you see. I am thinking about replacing mine not sure if it would be worth the cost.

 

[BushWakr - RIP]

The 190's usually provide about another 28 RWHP on an average truck... this will vary slightly depending on the pump settings/timing etc.....

Once the "novelty" wears off you should also see some improvement in your mileage. Keep in mind that this time of year means we're getting winter blend fuel and it is not as good a quality. In my case for example, with no other changes to the truck, the winter blend fuel costs me an average of 1 1/2 - 2 mpg easily.

I can ease that or even compensate for it if I add some good quality additive the tank of fuel. Generally it's the lower cetane rating that seems to lower the mileage, produces a rougher and lower idle and a bit more smoke.

When I add a good dose of Stanadyne PF or similar product the mileage comes back up, the idle rises a good 50 - 75 RPM and the smoke is 'just' noticably lighter. It's also worth mentioning that the winter blend fuel is not as efficient in lubricating the VE pump... all that lube's and cools our pumps is fuel so using an additive is a good idea year round.



bob... .

 

[Madurski]

It appears that my mileage has gotten worse :-( I definitely have more power than before, some hills that I would have had to just about floor it on before I make it up without reducing speed I can actually accelerate a little bit now I was getting around 14-15 and have gone down to 12-13, at least for the first tank through it.



I need to do some tweaking I think. I was going to start with the pump timing. Bump it up 10-12 degrees and see what effect that has on it. I don't want gobs of power added I just want it to be more fuel efficient than it was previously (back up to 18-19 MPG). I can tell that it needs tuned just by the idle, it is a little rougher and noisier.



If that doesn't help I will probably leave the timing advanced and start twiddling the injector pump. I know there is a page out there somewhere describing the adjustments that can be made, I just need to find it again. Does anyone think I should back off the timing if it doesn't improve things? Or should I start with the pump twiddling first?



Thanks,



Ron Madurski

 

[BushWakr - RIP]

Hi Ron,



I'd start with tweaking your timing first. Once you've done that, drive it for a few days and do some comparisons with you baseline readings.

Next I'd recommend you ease your AFC cone back a bit toward the lean setting... it doesn't have to be alot, just bit. Again, drive it with the new setting and make notes on the results you see.

Next, (particularly if you have low end/low boost smoke, I'd tighten up the AFC spring a bit.



Give that a try and let us know how you make out.



pastor bob... .

 

[Madurski]

I have perused the sight and checked out some other posts on setting the timing.



My question is:



If I am just moving the pump 1/8" or so do I need to find TDC first. It seems that all of the posts I have found mention doing so, but since I'm not really timing to the engine it doesn't make sense that I would have to do it. I understand that if I were to do it by the book (maybe next time I adjust the valves) I would need TDC for reference.



Thanks



Ron Madurski

 

[ctd8999]

Timing

Mad, Loosen the bolts holding the pump ( all of them ) and move the pump towards the head about an 1/8". It's kind of hard to move, for one of the bolts I had to bend one of my wrenches to get to it. Thanks Steve B.

 

[ctd8999]

Timing

Mad, No need to find TDC, forgot that. Thanks Steve B.

 

[Joseph Donnelly]

Snap-On sells a special wrench for loosening the injector pump nuts.

 

[Madurski]

Well, I did the injection pump timing. I had to bend up 2 wrenches to get the bolts undone/done but I bought a couple of cheap 13 mm ones and used those. Now that I have done it I think I could have gotten by with just one I used a small hydraulic lift to move the pump.



Anyway, I've run a tank of fuel through and my mileage is up to 16 MPG from 14/15 MPG before doing it. The idle has smoothed out considerably. No really noticeable power increase this time.



Next step is to take bushwhakr's advice and lean out the AFC cone a little bit.



Thanks guys.

 

[bgilbert]

Where is your starwheel set at? Low or high? With it set down low, towards the bottom of the pump, this will dump more fuel at low rpm, low boost, which you don't want if you want the best fuel mileage. You would want more boost-air, before the pump starts dumping fuel. Set it higher towards the top of the pump, try that before you turn the cone or do both at the same time. BTW you have a long, heavy truck, 4x4, auto, 16mpg is pretty good.

 

[Madurski]

My starwheel should be set at the stock setting. I was under the impression that the starwheel controlled the AFC Cone. I only looked around a little bit yesterday but I haven't found any specific procedures or recommendations on how to do the adjustment yet.



It looks like, based on a drawing in bushwakr's gallery, that there is a locknut on top of the diaphragm housing. Do I need to loosen this to adjust the starwheel and or AFC cone?



Thanks,



Ron Madurski

 

[cerberusiam]

The lock nut on top of the AFC is the smoke screw. It sets fuel delivery at an idle and essentially sets where in the cone the fuel pin starts its journey.



The star wheel is under the top of the AFC and the rubber gasket that holds the boost in. Pull the top off and the gasket and pin come out then the spring. The star wheel set to the bottom of the AFC housing gives less spring pressure on the fuel pin diaphram and allows it fuel faster with less boost. Bringing the star wheel up the threads adjust your no/low boost fuel to and how much black smoke it will make when you hit the throttle.

 

[chriscumminsdiesel]

Before you pull the diaphram and pin, put a mark on the housing and rubber to give you an index mark of where it was to start with. If you don't you may install the pin in a more fuel position wich won't help your fuel consumption.

 

[JLEONARD]

If you are not producing any or much black smoke on acceleration, then your adjustments may be ok for mileage.

A small puff when you really nail it at low rpm is about all you want if your in the mileage game.....

But for smileage... . well that's a whole 'nother story.

Just keep track of what you do... in case you want to go back to square one.....

Jay