Builds 1987 BJ74 Build: Let's daily drive a BJ74 in Los Angeles (1 Viewer)

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May 22, 2014
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Ah, where we were? Air in the fuel lines... ugh. Ok

So I did a bunch of experiments.

I investigated under the hood and everything looked fine. I decided to start from the back. I became worried it was the fuel pickup, so I got some fuel line from and strapped a gas can to the back of the trucking went for joy rides up and down my the hills of my local neighbor hood. I can tell you doing hard pulls up residential streets and stalling out halfway op got me a lot of hard looks from the local blue hairs... same results. At least it's not the fuel pick up. It would go for a while, then stumble and die.
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I was going to replace the lines with nice Viton fuel lines, but decided to go down to my local auto zone and grab a roll of 8mm line and just redo the lines going away from the tank to hedge by bets along with new clamps. Took me less than an hour to do the whole truck. I felt great about it! "This must be it!" I proclaimed to the sky! Then I went to the grocery store pretending it was fixed and it died half way there like an a******.

It couldn't be from the tank to the water separator. To be sure I I strapped a gas can with a couple of gallons of fuel to the bumper, pulling fuel straight from the lift and as what I had come to expect, no change.
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It was time to have a look at the lift pump. I decided to grab some carb cleaner and look for leaks, spraying connections to see if I sensed any change in idle. I did get a couple of positive results but it was completely random. I was convinced I was going crazy because I couldn't replicate it, so after burning through what must have been a half can of carb cleaner I started to take a close look at all of my soft lines. The soft line from the lift pump to the fuel filter isn't made anymore, and mine had some mild cracking. I decided to coat it in black RTV and wrap it in tape just to make sure that somehow it wasn't sucking air. I know, not my proudest moment, but we were now 2 weeks into this project and I was feeling pissed and desperate. As predicted no change... Before I did that I went down to a little custom hose place in Burbank. The guy said he could make a replacement with a different, modern fitting for a little over $200. I knew it wasn't the hose.... but if I had any results at least I knew I could get a replacement.
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Other bulls*** I tried: bleeding the injectors by cracking the lines while at idle. That was fun but changed nothing... on it went. I would tighten something then just let the truck idle in the driveway until it started stumbling and eventually die. My wife works nights for part of the week, so this process went on for days...
 
Joined
May 22, 2014
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So I did a little research and came with something I thought had to be the answer- the little plastic washers that going all of the connections starting at the lift pump inlet.

Toyota carries these believe it or not, part number 94712-77121, but they're in short supply and they're expensive. I ordered some from Toyotapartsdeal.com for significantly cheaper, but not all of them came in, so I supplemented with a couple from Toyota.
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Starting with the banjo fitting at the lift pump, I started pulling things apart to see what was what. I had read that sometimes you'll find the little screen on the lift pump banjo is clogged, which I would have been received to find, but true to the pattern developing in this project everything was squeaky clean. The plastic washers were old, and some were brittle. Fired up the truck and ... *drum roll*.... it did the same s***! COOL. This was a good thing to do, but now I was running out of things to check.

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Joined
May 22, 2014
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I was furious at this point. I decided to start all over again. It was time to isolate everything single connection, even if I knew that joint wasn't the culprit, just so I could systematically check the whole list.

I started at the lift pump and hooked up the gas can again, in my haste I splashed diesel all over the lift pump. I primed the system again and was about to start the truck in when I thought I heard a tiny *tick*.... *tick* from under the hood. It was so quiet that I had to hold my breath and stick my head under the hood. The sound went away, I primed it again and if I held my breath I could make out the tick between heart beats. I repeated the process several times, sticking my head as close to various parts of the fuel and lift pump as I could. I traced the tick back to the lift pump and grabbed a flashlight. There it was. Tiny bubbles frothing at the base of the primer out of the layer of diesel I had spilled all over the place. I actually used my phone screen to magnify it so I could see what was going on. Check it out:

 
Joined
May 22, 2014
Messages
518
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@cruiseroutfit sent out a replacement pump. I can't thank the crew over there enough. It didn't solve the problem. The big mystery is whether the first primer was misshapen and deformed my lift pump, or whether the inlet of my lift pump was bad. I even picked up a couple of extra copper washers. I scrubbed the mounting surfaces clean and tried all sort of different things. I annealed the washers. I tried doubling them up. I tried screwing them down hand tight, I tired cranking them down with force. No matter what I did the washers deformed and were spat out the sides.
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Joined
May 22, 2014
Messages
518
Location
Los Angeles
I went to DMP fasteners and picked up a 15mm compression washer that was way thicker than the factory ones. The ID of the washer didn't quite fit over the threads of the primer and they're wider than the mating surface of the lift pump, but with some messaging this would allow me to get the snuggest fit. The factory washers were very loose.
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The first step was to file down the ID so it would just thread over the pump.

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Using a grinder, I carefully shaved the OD of the washer down little at a time in order to have it fit inside the lift pump.
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Then I annealed the washer.
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Because the washer was thick I really had to muscle it down in order to get it to seat. This did the trick! I went for a test drive and the problem was solved. I posted all of these steps incase anyone else get's air in the system and needs to chase the leak down. I'm honestly not sure I this could have gone any other way for me it was dumb luck that I spotted the problem.
IMG_738AFB5F421F-1.jpeg


This was the lamest project, but I posted all of this to hopefully help someone with a similar issue in the future. This thread will get more interesting, I promise.
 
Joined
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@MyCruiserisaHogBeast Nice! I'm averaging 19mpg right now over 18 fillups going back a year.

Of course this is based on my odometer and 255/85r16 tires Mud tires. However my odometer and GPS are almost exact on. Speedometer is only a few kms off. So either someone changed my speedometer gear at some point, or it was just wildly off from the factory.

I only have almost 7000miles on the new engine, my average speed is 42mph according to the GPS and 90% of my time is 60~65mph 2 lane, no traffic but possibility of anywhere from no wind to 30mph head/tailwinds :rofl: I also have fuel turned up a little, and boost up to 11psi.

I had missed this reply! So one of the things I'm going to do in the near future is shim the waste gate and dial out the smoke. I want to have my pyro and boost gauge installed first. How did you get to 11psi? No intercooler I assume? I would love to toss an intercooler on this thing but there is no room and I want to keep things reliable and easy. What are your EGTs at full romp?
 

FJBen

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I had missed this reply! So one of the things I'm going to do in the near future is shim the waste gate and dial out the smoke. I want to have my pyro and boost gauge installed first. How did you get to 11psi? No intercooler I assume? I would love to toss an intercooler on this thing but there is no room and I want to keep things reliable and easy. What are your EGTs at full romp?


I have my wastegate shimmed to reach 11psi. I actually just ordered parts to make a Dawes Device, manual boost controller, they should be here tomorrow I believe so maybe this weekend I'll get that installed and remove the shim.
No intercooler at the moment, but I'm planning one. There isn't really an easy way with these that I have found, save for @PyroDAN is doing this setup which I never even thought about for a water to air setup. He still had to move/modify radiator for the heat exchanger...I have some other thoughts for that though.

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right now I can get over 1200F fairly easily by mashing it down. Thats why I'm going to max boost at 14~15psi. If that doesn't cool her down I will probably either turn fuel down a little or intercool.
 
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I have my wastegate shimmed to reach 11psi. I actually just ordered parts to make a Dawes Device, manual boost controller, they should be here tomorrow I believe so maybe this weekend I'll get that installed and remove the shim.
No intercooler at the moment, but I'm planning one. There isn't really an easy way with these that I have found, save for @PyroDAN is doing this setup which I never even thought about for a water to air setup. He still had to move/modify radiator for the heat exchanger...I have some other thoughts for that though.

20200804_175513-jpg.2421622



right now I can get over 1200F fairly easily by mashing it down. Thats why I'm going to max boost at 14~15psi. If that doesn't cool her down I will probably either turn fuel down a little or intercool.


I saw this too. While I do want to intercool, I don't want a complex setup. This set up is bitchin but my goal is to daily drive and I just don't want a bunch of extra stuff that can go wrong.

I was thinking that under 12 psi boost was a good goal. I've read that some guys have had good results without turning up the fuel. A little extra power would be nice but my main goals are fuel economy, reliability and no smoke. Did you turn up the fuel after running the additional boost?
 

FJBen

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I saw this too. While I do want to intercool, I don't want a complex setup. This set up is bitchin but my goal is to daily drive and I just don't want a bunch of extra stuff that can go wrong.

I was thinking that under 12 psi boost was a good goal. I've read that some guys have had good results without turning up the fuel. A little extra power would be nice but my main goals are fuel economy, reliability and no smoke. Did you turn up the fuel after running the additional boost?

I get it, underhood on the 13BT is already crowded enough. I do believe a simple air to air would help the 13BT out great, there just isn't a simple way to do it.
I turned up boost a little, then decided to adjust the fuel up a little bit, then the boost a little more. Most of the time I don't get to 11psi, unless I romp on it. I have only turned up the fuel a little, maybe 1/2 turn? I'm going to turn up the guide bushing as well as that helps with boost fueling.
 
Joined
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I get it, underhood on the 13BT is already crowded enough. I do believe a simple air to air would help the 13BT out great, there just isn't a simple way to do it.
I turned up boost a little, then decided to adjust the fuel up a little bit, then the boost a little more. Most of the time I don't get to 11psi, unless I romp on it. I have only turned up the fuel a little, maybe 1/2 turn? I'm going to turn up the guide bushing as well as that helps with boost fueling.

what did just increasing boost do to EGTs? Adding fuel? Guide bushing I’m assuming brings fuel quicker? Any diagrams or instructions on what does what in this fuel pump?
Yeah I’ve looked all over for a place to run just a small air to air it. It would be easy except for there being no place to put it.
 

FJBen

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what did just increasing boost do to EGTs? Adding fuel? Guide bushing I’m assuming brings fuel quicker? Any diagrams or instructions on what does what in this fuel pump?
Yeah I’ve looked all over for a place to run just a small air to air it. It would be easy except for there being no place to put it.


Just increasing boost can help EGT, BUT...you won't see a huge difference without more fuel. Boost is partially determined/dependant on fuel as well. Once you have more air, you can add more fuel and get more power if that makes sense. Boost alone won't really do it.

Adding fuel WILL raise EGT's. More fuel, more power/heat. Raising boost after raising fuel can lower EGTs.

The pump settings can be tweaked to help the overall fueling and boosting. Here is some great info from @gifu
The "Guide Bushing" should be a wheel that you can click up or down (once you remove that hex bolt). Clicking it up, will spin a threaded wheel clockwise, toward front of engine, reducing the spring tension beneath the boost-compensation diaphragm. This will effectively allow more fuel per boost; in other words, as you gain boost you will get fuel sooner, thus raising boost faster. This is a great adjustment for power vs. smoke. Clicking it down, will move the wheel closer to the diaphragm, in effect tightening the spring under the diaphragm, thus requiring more boost to move the diaphragm (and therefore reducing power, smoke, etc.).

The "boost compensator adjustment" is often called a "smoke screw" on other pumps. This adjustment is changing the non-boost level of the boost compensator; in other words, the amount of fuel the engine get's before the boost starts to push on the diaphragm. It's setting the unboosted diaphragm depth.

(ps: diaphragm is hard to spell. I don't like that word.)

and the thread that talks about it: 13B-T Fuel Adjustment - Power Increase; ANSWERED!


Everything I have done has been pretty minimal. Others have pushed these 13BT much harder, but so far I'm starting out slow.
 
Joined
May 22, 2014
Messages
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Just increasing boost can help EGT, BUT...you won't see a huge difference without more fuel. Boost is partially determined/dependant on fuel as well. Once you have more air, you can add more fuel and get more power if that makes sense. Boost alone won't really do it.

Adding fuel WILL raise EGT's. More fuel, more power/heat. Raising boost after raising fuel can lower EGTs.

The pump settings can be tweaked to help the overall fueling and boosting. Here is some great info from @gifu
The "Guide Bushing" should be a wheel that you can click up or down (once you remove that hex bolt). Clicking it up, will spin a threaded wheel clockwise, toward front of engine, reducing the spring tension beneath the boost-compensation diaphragm. This will effectively allow more fuel per boost; in other words, as you gain boost you will get fuel sooner, thus raising boost faster. This is a great adjustment for power vs. smoke. Clicking it down, will move the wheel closer to the diaphragm, in effect tightening the spring under the diaphragm, thus requiring more boost to move the diaphragm (and therefore reducing power, smoke, etc.).

The "boost compensator adjustment" is often called a "smoke screw" on other pumps. This adjustment is changing the non-boost level of the boost compensator; in other words, the amount of fuel the engine get's before the boost starts to push on the diaphragm. It's setting the unboosted diaphragm depth.

(ps: diaphragm is hard to spell. I don't like that word.)

and the thread that talks about it: 13B-T Fuel Adjustment - Power Increase; ANSWERED!


Everything I have done has been pretty minimal. Others have pushed these 13BT much harder, but so far I'm starting out slow.

That's the link I was looking for, awesome.
 
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My BJ70 I had had a 13BT swapped in when I bought it. I installed a air/air intercooler, but: no a/c, had to cut off half of the hood latch so no lock so did the hot rod route with the two pins and key through the hood. It was 2” wide don’t remember the rest of the dimensions. Running the plumbing wasn’t that hard, I did rotate the compressor housing to make it easier with plumbing.
 

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