Budget 4bd1t -> '94 FZJ80 Build

[Dougal]

I'm not seeing anything much on the injector in that photo. I'd look lower. Is that diesel on the boot into the intake manifold?
I'd be looking for hairline cracks on the lines to/from the injection pump. Also the banjo bolts if not clean can leak or even spray.

 

[lostih]

Yes...diesel all the way up there. Yeah the injector weeping doesn't seem like the culprit. The priming pump top was filled with diesel. It's screwed in hand snug though. I let it sit for a bit and dried what diesel I could. Now I'll start it and see if it's visible.

 

[lostih]

Found it...

Diesel pours out of the joint where my finger is pointing. Are these silver soldered together or ?

 

[Wheelingnoob]

Im not sure what solder they use. I have heard of some bypassing that gally pressure regulater and just using the one in the filter head. If you could find a way to plug the pressure reg in the gally you could use rubber hose from the banjo at the filter and just bypass the leaking line all together.

Other option if younare in a populated area is limp it to a machine shop and ask if they can repair it.

 

[Dougal]

Several pipes on mine have been brazed together for whatever repair reason. Silver solder would be better, but the brazing has given no trouble over at least 14 years.

 

[lostih]

So the line just came completely off. Blessing and a curse maybe. I was able to get some 3/8 fuel line over the nubbin left on the banjo fitting on the pump. Then I slid the long section of hose over the metal hose (it's a super loose fit) and double clamped it. Good enough to get me to a hotel. How much pressure are we talking about in this line? Think hose clamps will hold it?

 

[lostih]

Think a completely broken line can be crazed back together by an unknown brazer or would you go with the pictured field fix?

 

[lostih]

Jeremy...what does this line do? If I cap both ends will I be ok for the rest of the trip (800 miles?). I see a path forward to do that with the local hardware store in the morning.

 

[Wheelingnoob]

Nope the line from the filter and pump are the returns, I have heard of slme capping off the pump one and using only the filter one.

You are only dealing with iirc 12psi. With the pipe severed totally it maybe hard to get it brased back in the same position.

If you're temp fix holds I would be tempted to to call an isuzu/GM truck dealer a couple days down the road and have them bring in the part.

 

[Fromage]

It should be possible to heat up the banjo end and pull out the severed bit, and re-braze the line in there, and re-bend it to compensate for the lost length. I did all of my fuel lines this way, all you need is an oxyacetylene torch and some brazing rods. I would try and find an old timer farm repair place, I doubt they would have any trouble fixing that.

 

[lostih]

Thanks for the help guys. I put 60 miles on it this morning with no leaks and have an isuzu dealer working on getting me a new line overnighted for tomorrow. We'll see how it all works out. Still really pleased with the truck. Drove awesome this morning over some hilly freeway. It likes 70 better than 60.

 

[lostih]

Mileage dropped to 19.2 over the last 342 miles. I'll let it off the hook since it was spewing diesel for some of that

 

[Wheelingnoob]

Fuigured that fix would hold, its not a lot of pressure. Needs to be fixed but not a trip ender. Only 19.2......damn! my truck with the gas engine would not even get 250miles on a tank lol.

 

[lostih]

Made it home today. 1500 miles. Averaged around 19.5 for the trip uncorrected...so that should be 20ish. I'm pleased. Cruises great at 70-75. It made it over the mountain passes ok but drops to about 50-55 on the steepest ones and does them in 3rd at 3000rpm. I need to get my boost figured out and maybe add some more fuel, though today I got EGT's to 1200 first thing in the morning on a steep climb. Don't want to make it so that happens too much. Letting off the right foot ever so slightly solved the problem.

I also need to figure out the throttle cable a bit more. It still doesn't shift until you let off the gas when working its way through the gears...unless you are just barely pushing on the pedal. It'd be nice to get earlier shifts at moderate throttle. If I can't get this I'll be fine with it, but it makes the truck less lendable as you have to show someone how to drive it.

Overall pretty pleased with the truck on the trip. Next project is getting AC hooked up and boost figured.

 

[Dougal]

Made it home today. 1500 miles. Averaged around 19.5 for the trip uncorrected...so that should be 20ish. I'm pleased. Cruises great at 70-75. It made it over the mountain passes ok but drops to about 50-55 on the steepest ones and does them in 3rd at 3000rpm. I need to get my boost figured out and maybe add some more fuel, though today I got EGT's to 1200 first thing in the morning on a steep climb. Don't want to make it so that happens too much. Letting off the right foot ever so slightly solved the problem.

I also need to figure out the throttle cable a bit more. It still doesn't shift until you let off the gas when working its way through the gears...unless you are just barely pushing on the pedal. It'd be nice to get earlier shifts at moderate throttle. If I can't get this I'll be fine with it, but it makes the truck less lendable as you have to show someone how to drive it.

Overall pretty pleased with the truck on the trip. Next project is getting AC hooked up and boost figured.

If your 1200F is a true reading then that is no problem at all. I run mine to 750C (1380F) routinely.

 

[lostih]

Good to know. I assume its fairly close. I put the sensor in the manifold right before the turbo, but had to estimate the depth for the probe since the turbo was on already and I forgot to mark it when it was off. I took it out after it had been running and it seems to be close to the center of the flow.

I was thinking more about my boost issue as well. The boost sensor is right at the intake manifold after the intercooler. Am I right in thinking there could potentially be a 1-2 psi drop from compressor outlet to intake? Now that I have some miles on it I'm going to do a good once over on it and re-check for leaks everywhere. I hope its something simple. If I can't find any leaks I think I'll try swapping to the -16t turbo to see if there's something amiss with this turbo.

I suppose my thinking is that I need to have more boost before I add more fuel or I'll just be making more smoke and higher EGT's without much performance enhancement...is that reasonable logic?

 

[Wheelingnoob]

You're thinking is sound, the more boost you add the more air is pushed into the cylinders thus lowering EGT's. From there you can balence fuel and boost to get maximum power with safe EGT's and A/F.

The intercooler at 10psi should not take away 1-2psi. If you where running 20+ psi maybe but that depends on the intercooler size and design. I would not expect that kind of a boost drop on a decent intercooler at 10psi.

I had a customer once that brought his car in with a complaint of lack of boost. We worked on it for a few hours (had a huge front mount intercooler). It turned out he had swapped turbos 6 months before and been fighting this lack of boost ever since, swapped turbos back only to bave the same issue. Brought it to us as a last ditch effort before he sold the car. We found two shop rags in the inlet side of the intercooler plugging more than 70% of it. We had 35psi pre cooler and 17psi post. We found it by putting a second boost guage pre cooler. 2 hours later he had the car back happy as a clam albeit slightly embarrased.

So take what you will from that story. Remember to diagnose things with a opend mind. I would try putting your boost guage pre cooler to see if there is anoticable diffrence. Also try putting more load on the wastegate when closed, mine has 3/16" preload and a 1.7bar actuator spring.

 

[Mr Cimarron]

Yours definitely cruises better than mine. Mine will do 75 no problem but the RPMs are high for the power band. Right now 60 is the sweet spot and 65+ MPGs start to go down. Luckily for me I am a feather foot driver. Eventually I will look into gears so I don't have to do the "go on ahead I'll catch up when you stop".

 

[ylexot]

50mph in 3rd up 6% grades sounds like its running decently well. I cant wait to hear how it does once you get your boost and fuel worked out.

It seems unlikely that you would drop 10-20% of your boost in the short span of your big intake plumbing. It looked like you had plenty of crossectional area for you volumetric flow rate. Do you have too much volume making your intake a reservior? Is there a restriction in your intake that isnt visble in the photos?

Checking for leaks is a good place to start. Then, it's time to use your hotrod turbo!!!

 

[lostih]

heh...yeah I could have a rag in there

Tell me more about wastegate pre-load... I just held it closed with my finger and adjusted the actuator rod to keep it there. From your post I'm thinking that you'd adjust the rod even shorter and slip it on to give it the pre-load? Because of my clocking I'm at the end of the rod's adjustment already, but I suppose I could adjust the mount points to get me some more preload.