See RECAP at bottom for important info. Long Post

Hi Everyone. I’m new here and trying to figure out how this whole diesel thing works. I have a 1997- 12 valve - 5 speed manual with 245,000 on it. I bought it in June of last year and have put over 25,000 on it so far. As soon as I got it I had the KDP and 5th gear nut fixed, the fuel filter replaced and an oil change. Since then I have had all the breaks replaced, put new tires on it and oil change every 5K. (And quickly learned how expensive these trucks can be!). One of the reasons I was looking for this truck is because I wanted to start to work on my own vehicles and this seemed like a good one to start on. I forgot/didn’t realize that I needed replacethe fuel filter so often.

Recently I have noticed that my power has decreased, did some research and learned about the fuel filter. So I had that replaced last week (about 15K too late). Having just moved to a new state I started calling around and found a shop that came highly recommended and had good reviews online except for one review that BLASTED the shop for selling unnecessary parts and labor.


Anyways LONG story short, after having a very dirty fuel filter replaced my truck is still low on power, puffs white smoke (although not a ton) at start-up when cold, and sometimes under load. The guy at the shop who replaced my filter seems very knowledgeable and everything he says makes sense to me BUT he is HELL BENT on selling me a FASS fuel system for a grand, some overhead cam workand new injectors another grand. ($2,000 Total just to start)


Now after some research I have come to the conclusion that I probably do need a new lift pump, injectors probably wouldn’t be a bad idea and I’m not sure what overhead cam work he is talking about but he says it would beeasy while doing the injectors. I actually thought my lift pump was going out or gone before I had the filter replaced so that’s no surprise. But the FASS system sounds ridiculous to me and the fact that he is pushing me really hard to get it, is really pissing meoff. (I think he is a power junky; Which is fine, but not what I’m looking for).


So here I am, I found this site and everyone here seems cool. Can someone help me out here?


RECAP:
About Me:
First ever diesel (’97 12Valve, 245,000, 5 speed manual).
I know, I know…. I have No Fuel pressure gauge….
But I have a pyro and turbo PSI meter thing. That came with the truck.
I’m not very mechanically knowledgeable but willing to learn.
Not a lot of money to spend.
I’m looking for a reliable long running truck, not HP.
Although easy low cost minor HP improvements along the way welcome.








Symptoms:

• White smoke @ start-up and under load (Not a lot of smoke, just puffs)
• Low Power - compared to 15 months ago.
• New Fuel Filter that replaced a LONG over due old one.
• I Should probably clean out my Giant Air Filter(came with truck)
• No ticking or knocking sound.

Questions:

What should I do?? Am I on the right track?


What is the Overflow valve on the injection pump? And how hard is that to fix?


What preventative maintenance should be done while I’m in there working on this? EX: fuel lines, Overflow Valve, Pre Filter Screen?


I am still very confused about the fuel plate in the Injection Pump, and all of these angles/numbers floating around with them. But it seems like a good easy way to increase HP.


I have lots of other questions regarding this truck like what to and what not to upgrade (like what kind of injectors and why).


Also I work at a ski hill in the winter where it gets very cold. Should Iput some kind of heaters on my fuel tank, filters, or oil pan while I’m messing around with my fuel system? What additives to use/not use (howes, Duce Juice, Power service, 2 stroke)?


Thanks for taking a look and helping out!

 

You definitely do not need a fass system, they are a nice electric pump with lots of potential. But, the reliable piston pump is good for 500-600 hp, and did I mention reliable?

A fuel pressure gauge really helps nail down performance issues and can be done for cheap. Other common problem is leaking fuel lines between lift pump and tanks, which can let air in but no fuel out.

Not sure what kind of overhead cam work a 12v could need, with no overhead cam... Do a little research and weed out the scam artists.

 

He's probably talking about the fuel cam plate (aka just: fuel plate).

Well, at 245k., things are going to be worn out, even on the mighty 12 valve.
You do not need a fuel psi gauge installed permanent, but you need a test gauge to see if your lift pump is providing much pressure. The two 12valves I've owned, I had to replace lift pumps at around 150k. Same on my friends' trucks.
Overflow valves are another common weakness, if it's 10 years old I just replace them.
If your fuel psi is good and you're still getting white smoke, then the engine timing needs to be reset.
Also make sure your fuel heater assembly isn't burned at the connector, either seeping fuel or letting air in.
Also make sure your fuel return line behind the pump isn't old and cracked, that'll ruin your day when it splits.

 

Thanks! The fass system didn't make any sense to me, and the fact that he is pushing it so hard will probably drive me away, which is too bad, I really wanted to like the guy.


I am planning on changing out the hoses from the fuel tank to the lift pump, but its my understanding that it is a metal hose from the tank until it needs to turn up to the lift pump (about 4' of plastic hose). Is that right or am I missing something?


Would I have to change any turbo or fuel settings after moving from sea level to 5500+ ft in elevation?

 

At the fuel tank there are 2 quick-connect fittings, one for supply and one for return.
Sometimes the metal parts on the tank get corroded. (Marked fuel line connection)



You can use simple 10mm ID hose for the supply line and 8mm ID for the return. (You will need about 2 meters to 3 meters of each.

If the metal parts are corroded you can either replace them (spendy) or get a draw straw an modify your fuel tank.

 

What is the Overflow valve on the injection pump? And how hard is that to fix?

it sits on the front of the ip and is easy and inexpensive to change, at least compared to lift pump. I have replaced mine twice in about 15 years. when you find it, the best tip I got was to file the notch above it for additional clearance, otherwise it is very tight getting it in and out.


What preventative maintenance should be done while I’m in there working on this? EX: fuel lines, Overflow Valve, Pre Filter Screen?

lots of people eliminate the fuel heater as it has a tendency to leak. I am going to rebuild mine with all new parts.


I have lots of other questions regarding this truck like what to and what not to upgrade (like what kind of injectors and why).

look up DSS steering brace. made a big difference on mine


Also I work at a ski hill in the winter where it gets very cold. Should Iput some kind of heaters on my fuel tank, filters, or oil pan while I’m messing around with my fuel system? What additives to use/not use (howes, Duce Juice, Power service, 2 stroke)?

Can you plug in? A block heater is usually enough... If you can't plug in, there are heaters that burn diesel to heat your coolant, but they are $$$. I bought a little toyota 4x4 gasser for the price of the heater. Most common fuel additive I see around here is Power Service. I've used a couple different ones off and on and can't say I've noticed any difference (unless we're talking bio, but that's another topic


Would I have to change any turbo or fuel settings after moving from sea level to 5500+ ft in elevation?

sounds like you already have a big air filter. other than that, i don't think so (I live at 9000' and haven't done anything to mine)

 

ps. I've also replaced my lift pump a couple times. they do sometimes go bad.
I don't remember ever having white smoke as a symptom though... just low power.

 

Change the over flow valve.
Sounds like that is the low power / smoke problem.