Engine/Transmission (1994 - 1998) 12 valve injectors

[ra340]

I just picked up a 95 12v auto 4x4 truck that stock except for a 4" striaght pipe and removed turbo silencer ring. The truck has a miss when cold (I hear that is normal) but it has a slight miss at idle and just above(when warm in the summer). I bought it from a friend and his tech recomended new injectors. I had other diesel guys look at it and everyone think it needs injectors also. I am thinking of getting a set of marine injectors for around $250 or a set of honed matched injectors $500. I found both of these on ebay. Are there better options? The future plans for the truck are gages and a fuel plate after this, but I want to get the the engine to run right before I change anything else. Right know I value milage when towing over max power. thanks

 

[Vaughn MacKenzie]

Hi ra340, welcome to the 12-valve club

Depending on how many miles you have you could remove and clean the tips, but if you're around 200k or more mi replacing them isn't a bad idea. Some places like Piers Diesel matches marine injectors in sets so you get good balance on an affordable injector. But DDP does a great job on their honed injectors.

Hopefully injectors will take care of the slight miss, but 12-valves have a propensity to this kind of miss and it's difficult to exorcise in some cases. I would think about replacing the overflow valve and doing complete maintenance on the preheater and filter screens replacing all gaskets: Fuel Pre-Filter Cleaning on Ram/Cummins

Next thing you want to do is kill that KDP if it hasn't been done. Have fun and keep us posted!

 

[The patriot]

You WILL lose some MPG with the 370 marine injectors, because you will want to push the petal down more.

I love my 370's, but I have the 215hp engine.

Eric



PS Welcome aboard!

 

[JFaughn]

Run 2 tanks of 20% bio-diesel [ carry an extra fuel filter , bio is the only cleaner that will clean enough to plug the filter ] besides the bigger holes warn in the old injectors will fit the bio better .
Before adding power / fuel , you might want to up grade the trans . , it will not take much more that stock power , then you can get carried away with mods .

 

[CWerner]

Run 2 tanks of 20% bio-diesel [ carry an extra fuel filter , bio is the only cleaner that will clean enough to plug the filter ]

If the filter is between the tank and injection pump, is the junk plugging the filter coming from the bio fuel?

 

[JFaughn]

The point is , that its cleaning everything that it contacts ,
You can find bad bio if you want , but with a little checking , you can find a producer that has a good rep.
If as you try to suggest it was coming from the bio , then I would have more than 1 plugged filter in the 40,000 miles of using it .

 

[ra340]

Thanks for all of the replys! I forgot to add in the post that the truck has 148,000 miles on it. The guy I bought it from has had since 102,000. The trans was rebuilt with a shift kit around 90,000. It has had a slight miss since he bought it he says.



I am not driving the truck every day yet ( I still have to sell my gasser ram). My list of things to do are in this order. Changes all filters and sediment traps in fuel system. upgrade injectors to get it run right and a little more power. A BD pressure lock for the trans to help it deal with more power. do the KDP when I put all new hoses on and do a complete coolant change. Then add boost, pyro, trans temp gages. Then add a fuel plate for a little more power.



Right now I am leaning toward the honed injectors over the marine injectors. Mainly because the people selling honed injectors claim better milage. The 2 sources I have found for honed injectors are a guy On ebay out of Omaha Nebraska with 100% positive feedback, and dynomite injectors in Washinton state. Has anybody used these products? Thanks!

 

[Joe G.]

Email me for my write up on the fuel suppy system, how it works and how to fix it. That will give you a good understanding of what you have.

 

[bmoeller]

You WILL lose some MPG with the 370 marine injectors, because you will want to push the petal down more.

I GAINED mileage going to the 370s. Even with a heavy foot. I do think the PDR40 turbo was part of it though. Less restriction. The stock 12 housing is a real choke point with 4. 10s and high RPMs on the interstate.



The 370s do make good cheap power, but I would suggest a set of DDP injectors. The stage 4s are bigger than the 370s, but with the same EGTs, more power, virtually no haze at idle (at nearly any ambient temp after warming up), and burn cleaner (at least if you have enough boost :-laf). Takes less to clear it up.



Stock, I couldn't get over 16. 1 mpg. With the 370s and 40, I got up to 17. 5. Right now, it is ~14, but the flatbed I put on dropped it by 2mpg.

 

[The patriot]

Must be the turbo. My truck is stock except for the 370's and the BHAF.

Oh yea, I twisted the star wheel a little:-laf that might have something to do with it.

I get about 15 on the highway latley. I think I need to re time it. I have 3. 54's.

With the 32' TT it's more like 11. 5-12. 5. I set the cruise @ 70-75 once I'm out on the open road.

Eric

 

[bmoeller]

FWIW, I did run the turbo for a month or so, prior to the injectors. Took a while to get the injectors ordered.