Hydro-idi
Full Access Member
Okay will do. Im still a bit new to this website and am not the smartest when it comes to computers.....which is why I love my truck! I will take care of that now. Thanks again guys I really appreciate your advice.
Ebay Injectors Help
- Thread starter Hydro-idi
- Start date
icanfixall
Official GMM hand model
What puller posted is not completely correct. As a pump wears it retards the timing. As injectors wear the springs loose pressure so they tend to pop early. That advances the timing. Think about this for a monent. An injector pops open at 1200 lbs. We all know that way too low. The pump can push 4000 to 5000 lbs if needed but the injector is what controls the pressure needed. Then you install new injectors that are set for 1850 lb. Now the pump is trying to pop open the injector but it takes a little while longer to do so. This is where timing changes when replacing injectors. Anytime a pump or injectors are changed you "should" time the engine... But few actually do this. So members have had their trucks for several years and never had them timed. A imprperly timed engine leaves hp and fuel mileage on the table. Time the engine or have it done but... Don't allow some "mechanic" to time it by ear and take your money doing so. Most any member here will time your truck by ear. You just mail them some money... Thats what the guy is doing to you and taking your money. I have spent several thousand dollars buying timing meters. I rent them out to members here with clear instructions how to do this. They come with the special tools for the job. Many have participated in the program too. I don't make a killing on this but I do break even. As for the thoughts on degrees of advance. Factory is 8.5 + or _ 2 degrees. Most here will time to at least 8.5 advance. I like 9.2 to 9.4 advance. My meters will time down to a 10th of a degree thru the micro processer in them. They are that accurate. Because of the bad fuel we have to run we tend to advance to 9 or 9.5. Some even go up to 10.5 advance and get away with it.
gdhillon
Full Access Member
i guess, I just asked him if they pop test and all he/she said was "Yes."
I didn't really inquire more b/c i have a set from Russ coming
Hydro-idi
Full Access Member
I cant believe the knowledge you guys have about these engines it amazes me 
. I now know that I will need to properly get my engine timed after installing new injectors. But I do have one more question. I do run used atf for fuel.....sometimes even 100%. Will that have an effect on engine timing, since it practically has no cetane? So far I havent noticed any differences with used atf as fuel. Pretty much runs the same, smokes the same, with the exception of engine starting the same. The one thing I have noticed is the engine running quieter and smoother. Is this affecting timing???
. I now know that I will need to properly get my engine timed after installing new injectors. But I do have one more question. I do run used atf for fuel.....sometimes even 100%. Will that have an effect on engine timing, since it practically has no cetane? So far I havent noticed any differences with used atf as fuel. Pretty much runs the same, smokes the same, with the exception of engine starting the same. The one thing I have noticed is the engine running quieter and smoother. Is this affecting timing???
gdhillon
Full Access Member
How do you filter your atf? I am going to start running wmo as soon as I save enough $ to buy/make a filtering setup
Puller
Puller
He asked if he had to get the timing done and I said no you don't. I guess I should have stated that for peak performance you should get it timed however most don't. So my bad. Most people don't go the extra mile on anything when they replace parts. Honestly if he's that concerned about performance he should make sure when the injectors are pop tested they provide a data read out sheet for each injector and they should be within .5% at least this is what we hold our performance injectors to on our gas applications for racing (But then again I have full control of each individual injector, dead time, latency and injection timing).
Hydro-idi
Full Access Member
I made a very simple filtration apparatus using a filter base plate, Napa Gold 3374 6 micron filter with magnets attached, hose, and a barrel hand pump from Harbor Freight. Not the fanciest setup but it was cheap and easy to make. The filter will pump about 120 gallons before I have to change it. When running wmo or watf, it is important to change the engine fuel filter every 5k or so. My fuel filter on truck also has magnets for extra assurance. Now I hear there are extra steps in regards to filtering and burning wmo as fuel. If someone says otherwise, please feel free to tell me because I got a stash of wmo at a mechanic shop.......I just don't feel confident using it as fuel and filtering it through my watf setup.
icanfixall
Official GMM hand model
Puller... Your are correct in what you just posted. Many here will not adjust the timing when they change the pump or injectors. Nor will most know what the injectors pop at. Usually pop pressure within 25 lbs is acceptable but. For each 1 thousands shim added or removed the pop pressure changes 50 lbs. So it difficult to make an finer adjustements than that. Really anytime the pump or injectors are changed the timing needs to be checked for best results.
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