Couple of misc. questions

[1994IDI]

I have injectors coming for the truck in my sig, and am wondering if I will need it to be timed once they have been replaced.

Also on that same truck, can anyone clarify the procedure and effects of adjusting the wastegate rod to allow more boost on the factory turbo? I will be adding an intercooler in a couple weeks, and would like to regain some of the boost I will lose to the added area to be pressurized.

Thanks for any help.

 

[SLC97SR5]

I'm not sure about timing after injector replacement but I would say yes, it's necessary for best performance.

The Intercooler will likely sap 2-3 psi of boost so shortening the rod will help the turbo make up for it. I would shoot for 12psi.

 

[Full Monte]

I have injectors coming for the truck in my sig, and am wondering if I will need it to be timed once they have been replaced.

Also on that same truck, can anyone clarify the procedure and effects of adjusting the wastegate rod to allow more boost on the factory turbo? I will be adding an intercooler in a couple weeks, and would like to regain some of the boost I will lose to the added area to be pressurized.

Thanks for any help.

I doubt it will need to be re-timed. You don't re-time a gasser when you replace the spark plugs, do you? As long as the replacement injectors are the same type as the originals, just put them in and go.

 

[subway]

I doubt it will need to be re-timed. You don't re-time a gasser when you replace the spark plugs, do you? As long as the replacement injectors are the same type as the originals, just put them in and go.

gassers are fired by electronics not the fuel pressure. Raising the fuel pressure to pop off can cause the injectors to fire later since it can take longer to build it up.

it would be a good idea but i don’t know how necessary it would be.

 

[Abull78]

if you are going to go through the trouble of replacing injectors I would time the pump anyway. Also, the old injectors were worn so pop off pressure was lower then when they were new and their flow was probably less than when they were new too. If your pump was timed to those injectors retiming is almost a must. If you want to take advantage of what the new injectors are capable of give the IP some attention.

on the IC,.....i don;t know the specifics of the IC, what type, make, size, etc. BUT boost is a measurement of pressure through the intake tract. a properly sized IC isnt going to give very much restriction. If after installing an IC you see a pressure drop then the IC is doing its job i.e, flowing adequately AND cooling the air charge. from a standpoint of taking full advantage of your hardware, if you are able to lower intake pressure you should raise your boost. As far as wastegate adjustment, why not try bypassing the wastegate and see exactly where you want to have it actually open.

 

[1994IDI]

I doubt it will need to be re-timed. You don't re-time a gasser when you replace the spark plugs, do you?.

No, but I don't see the relevancy?

Abull, I don't foresee much restriction. I will be using a 31"x12"x4" intercooler, with 3" piping. I know I will lose boost since I am pressurizing more area. I can only make 7 psi now, with my foot on the floor and going up hill. After the intercooler I think I will lose even more. What I need to know is how to gain back some of that boost, (which I now know to shorten the wastegate rod), and what I can gain from doing it. Would you explain what you mean by bypassing the wastegate?

Thanks for all the help guys.

 

[Abull78]

No, but I don't see the relevancy?

Abull, I don't foresee much restriction. I will be using a 31"x12"x4" intercooler, with 3" piping. I know I will lose boost since I am pressurizing more area. I can only make 7 psi now, with my foot on the floor and going up hill. After the intercooler I think I will lose even more. What I need to know is how to gain back some of that boost, (which I now know to shorten the wastegate rod), and what I can gain from doing it. Would you explain what you mean by bypassing the wastegate?

Thanks for all the help guys.

well hopefully you have an external gate, if so, there is a tube leading from the compressor housing to the wastegate plunger. either by adding an inline valve to that tube or by capping the tube outlet on the compressor housing you will stop the gate from opening.

as far as losing boost by adding the IC, even if your IC was a mile long you will still hit the same boost number, it will definitely take longer to pressurize the larger volume but you will still hit the same psi because your motor will still only accept a specific cfm being pumped into before it starts making backpressure/boost. Now, since the IC is going to provide you with a cooler air charge, which means a denser air charge, you exhaust is going to have more volume which will spinn the turbo sooner and harder, which ultimately means more boost!

 

[Dsl_Dog_Treat]

The new injectors will affect the timing as they will have a higher pop off pressure than the old ones thus slightly retarding the timing as it will take longer for the new injectors to open.


As far as lost boost, the cooler more dense air will make up for the couple pounds you will lose.

Only seeing 7psi makes me wonder if you have a boost leak somewhere or ya need to turn up the IP for more fuel.

How many miles on the current IP?

 

[1994IDI]

I know powerwise I will be better off with the cool air, but more boost and more cold air can only make it better.. lol I thought I was right online with most other folks who have a stock turbo. I have not had a boost gauge until this summer, and it has been over one hundred degrees pretty consistently lately with high humidity, so I have not been working with very dense air. The best I've seen is 7.5 lbs unloaded. So I'm sure loaded I could come close to 9-10. The IP is up two flats, and is the original with 87,000 miles. On a side note, I m waiting on it to need a Moose replacement!

That sounds like good words of wisdom on the timing and the pop pressure. I will start looking for a shop that can do it. 9.5* is where a lot of members are running correct? Will someone remind me what that type of timing is called? I am not experienced with diesel timing at all.