Builds Isuzu 4BD1T Lexus LX450 (Land Cruiser) Build (1 Viewer)

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I don't have any meaningful thing to say, but I was reading old threads and I just wanted to remind you that when you find the right turbo combination you are powder coating it pink with sparkles.
 
A boost leak will still build boost. It'll just be later and lower than expected. It's actually wheel to housing fit I was specificially wondering about.

Can you bypass the intercooler for a test too?
 
I don't have any meaningful thing to say, but I was reading old threads and I just wanted to remind you that when you find the right turbo combination you are powder coating it pink with sparkles.
Yeah when I settle on one it will be done.
A boost leak will still build boost. It'll just be later and lower than expected. It's actually wheel to housing fit I was specificially wondering about.

Can you bypass the intercooler for a test too?
The clearance is in the .5mm range. I would not say the clearance is any grater than any other turbo I have used/built.

I do not have a easy way to test with out the intercooler. What I plan to do is test pressure pre intercooler so I can see if its a restriction or not.

I really hope it's just a boost leak somewhere...
 
Hey Jeremy, good to see you got it on the road!

The issues you are having sound not unlike my experience on the TD04hl on my jeep.

The thing ran great, just a lethargic pig. I was battling several issues, like a faulty 700r4, some exhaust leaks, etc. When I turned the fuel screw, there was literally no change in egt/smoke/power. It barely maintained freeway speed on flat ground, and the whole time my egts were very high.

Near as I could tell, my timing was so far retarded it was almost back around to right. I advanced it as far as I could without taking the pump off, and it made a huge difference. My EGTs went to a manageable level, and turning fuel screw actually made something happen. I never did spill time it because I scrapped the project shortly after, but my feeling is the harmonic balancer must have slipped the mark prior to my owning it, and the pump was serviced and reinstalled according to a faulty mark.
 
Hey Jeremy, good to see you got it on the road!

The issues you are having sound not unlike my experience on the TD04hl on my jeep.

The thing ran great, just a lethargic pig. I was battling several issues, like a faulty 700r4, some exhaust leaks, etc. When I turned the fuel screw, there was literally no change in egt/smoke/power. It barely maintained freeway speed on flat ground, and the whole time my egts were very high.

Near as I could tell, my timing was so far retarded it was almost back around to right. I advanced it as far as I could without taking the pump off, and it made a huge difference. My EGTs went to a manageable level, and turning fuel screw actually made something happen. I never did spill time it because I scrapped the project shortly after, but my feeling is the harmonic balancer must have slipped the mark prior to my owning it, and the pump was serviced and reinstalled according to a faulty mark.
Thank you very much for weighing in! I remember the issues you have and they. Sound very similar to mine. Mine will react to adjustments to the fuel screw though both boost/EGT's and smoke. But other than that the same I do have enough power to accelerate when at hwy speeds just slowly.

Once I pressure test my intercooler pipes I try and advancing the timing. Mine has started exhibiting another trade of retarded timing recently and that is very hard/smokie starting when cool even after a glow.

Again thank you very much for you input!
 
Maybe light at the end of the tunnel. The one thing you guys had in common was starting with a non-running engine where everything has been off and back on again.

The guys who have had no issues have been turbocharging engines which were already running great. So far fewer things to check.

For the timing. Advance it until it starts nailing. Then back it off until you're happy.
 
I actually had purchased a running driving truck, so mine wasnt apart. I meant that he pump had maybe been pulled/reinstalled prior to my owning it.

Jeremy, One thing about these engines, they will start perfectly in sub zero temps. at least mine did. never needed GP ever.
It really sounds like a timing issue. Obviously you have no exhaust leaks?

with the hard starting issue, I don't believe it has anything too do with the turbo/piping/leaks etc.

What are your compression numbers out of curiosity?
 
Are you confident your injectors are clear? if memory serves, you had them rebuilt.
And you are not getting smoke?
 
How cold is "cold weather"?

I fought with timing on my swap for a long time, since it is electronic and can't be set with conventional means (spill, dial indicator etc). Once I got it right (zeroed the timing marks and used an electronic pulse adapter), the most noticeable difference was how easily it would start when cold, down to freezing. But, it was -10C (10F) this morning and I doubt it would start very well without glow plugs, especially with 15W40 in the pan, so "cold weather" is open to some local factors...
 
How cold is "cold weather"?

I fought with timing on my swap for a long time, since it is electronic and can't be set with conventional means (spill, dial indicator etc). Once I got it right (zeroed the timing marks and used an electronic pulse adapter), the most noticeable difference was how easily it would start when cold, down to freezing. But, it was -10C (10F) this morning and I doubt it would start very well without glow plugs, especially with 15W40 in the pan, so "cold weather" is open to some local factors...

Coldest it normally gets where I live is -10C. My 4BD1T starts fine in those temps as long as the batteries are good so you get a decent cranking speed.
But once started it needs extra throttle for the first 30 seconds to keep it alive.

My glowplugs have never been connected.
 
It was - 5c the other morning and it barley started with a jumper wire on the glow plugs.
 
If the Pyro gauge is not the problem, retarded timing could be part of the issue. Correct injector operation, timing, compression & turnover speed all play a big role in cold weather starting .
You also wont make decent boost without being able to put the extra fuel in. What is your setting over stock now?

What procedure did you use to spill time the pump? First I always double check the crank timing mark is TDC when #1 piston is at TDC and remark if req. simply remove injector or glow plug and use a dial gauge. I do this regardless of new components or not. I also find a 4" piece of old injector line handy to fit to #1 delivery valve holder (with spring & valve removed) bend it over so the open end points down slightly with a mitre cut on the end. You will easily see exactly when fuel stops flowing, if you call it stopped too early timing will be retarded & always work in the normal direction of rotation of crank. It is easy to get this 5 or 6 degrees out. From new they were a couple of degrees either way.

I also vaguely remember you saying the injector pop pressure are set higher than spec of 2630psi (180 bar). Setting at 200 bar yields 2*+ retard & 240 bar up to 8* or more depending on pump condition. I usually set them @ 185 bar with new nozzles.

An injector pump with very low feed pressure will also give symptoms of being retarded and abnormal combustion temps.

If I were you I would take fellow mudder up on the offer of that diesel timing light. It will make your life so much easier and also give accurate info. Even 3 degrees is a lot if your trying to diagnose a problem. You will also be able to check the mechanical advance is working as it should, Just make sure you double check the crank timing mark.
I think having the pump sitting 3/16" from factory position would raise an eyebrow or two in my workshop and warrant further investigation unless there is good reason for that.

The other issue I have come across is mismatched injector bodies & nozzles, probably only 20 or so times in the last 30 odd years. This is where someone has replaced injectors and either the body is from a different engine or have fitted the wrong nozzles( usually in haste to keep the thing running). If you ring a good diesel shop and give them the nozzle & body numbers they should be able to tell you if they are a match and the engine that it should be fitted to, This will also give you abnormal EGT's and sometimes worse. The last one I did was a 6bd1t in a truck that had injector bodies out of a 6bd1t in a Hitachi excavator and 6 hole nozzles that were for a Hino truck and had been that way for quite a while, power was down, got hot when worked hard and 3 burnt valves. I was told there were over 60 different injector body/nozzle combos for the 6bd1 series & nearly the same for the 4bd1 series engines. Pretty cheep & easy to check.

The bowl in the piston was it the exact shape of the old pistons?

And if you are going to test the intercooler and hoses for leaks, take the rocker gear off so the intake valves are shut then you can test the seal between the intake & the head at the same time just by pressurizing from the turbo end.

You could also check the cam timing @ the same time that the rocker cover is off with 2 dial gauges just got to check that the exhaust opening to inlet closing overlap is centred at TDC.

Other than that an intake ( hose sucking partly shut restriction gauge to check, cobra heads are better for tight intake bends at turbo) or exhaust restriction, weak valve springs, too tight valve clearance.

With the turbo, the clearance cold side should be .009" -.012" from the minor to the major, hot side .016" from the minor to the major, that will be both sides of the wheel on the minors. you may loose up to 15% efficiency for every .010" increase in clearance. I'd also run the measuring stick over the wheels just to make sure they are correct but I'm sure you you've already done that.

Sorry for the long post, something might be useful.
 
If the Pyro gauge is not the problem, retarded timing could be part of the issue. Correct injector operation, timing, compression & turnover speed all play a big role in cold weather starting .
You also wont make decent boost without being able to put the extra fuel in. What is your setting over stock now?

What procedure did you use to spill time the pump? First I always double check the crank timing mark is TDC when #1 piston is at TDC and remark if req. simply remove injector or glow plug and use a dial gauge. I do this regardless of new components or not. I also find a 4" piece of old injector line handy to fit to #1 delivery valve holder (with spring & valve removed) bend it over so the open end points down slightly with a mitre cut on the end. You will easily see exactly when fuel stops flowing, if you call it stopped too early timing will be retarded & always work in the normal direction of rotation of crank. It is easy to get this 5 or 6 degrees out. From new they were a couple of degrees either way.

I also vaguely remember you saying the injector pop pressure are set higher than spec of 2630psi (180 bar). Setting at 200 bar yields 2*+ retard & 240 bar up to 8* or more depending on pump condition. I usually set them @ 185 bar with new nozzles.

An injector pump with very low feed pressure will also give symptoms of being retarded and abnormal combustion temps.

If I were you I would take fellow mudder up on the offer of that diesel timing light. It will make your life so much easier and also give accurate info. Even 3 degrees is a lot if your trying to diagnose a problem. You will also be able to check the mechanical advance is working as it should, Just make sure you double check the crank timing mark.
I think having the pump sitting 3/16" from factory position would raise an eyebrow or two in my workshop and warrant further investigation unless there is good reason for that.

The other issue I have come across is mismatched injector bodies & nozzles, probably only 20 or so times in the last 30 odd years. This is where someone has replaced injectors and either the body is from a different engine or have fitted the wrong nozzles( usually in haste to keep the thing running). If you ring a good diesel shop and give them the nozzle & body numbers they should be able to tell you if they are a match and the engine that it should be fitted to, This will also give you abnormal EGT's and sometimes worse. The last one I did was a 6bd1t in a truck that had injector bodies out of a 6bd1t in a Hitachi excavator and 6 hole nozzles that were for a Hino truck and had been that way for quite a while, power was down, got hot when worked hard and 3 burnt valves. I was told there were over 60 different injector body/nozzle combos for the 6bd1 series & nearly the same for the 4bd1 series engines. Pretty cheep & easy to check.

The bowl in the piston was it the exact shape of the old pistons?

And if you are going to test the intercooler and hoses for leaks, take the rocker gear off so the intake valves are shut then you can test the seal between the intake & the head at the same time just by pressurizing from the turbo end.

You could also check the cam timing @ the same time that the rocker cover is off with 2 dial gauges just got to check that the exhaust opening to inlet closing overlap is centred at TDC.

Other than that an intake ( hose sucking partly shut restriction gauge to check, cobra heads are better for tight intake bends at turbo) or exhaust restriction, weak valve springs, too tight valve clearance.

With the turbo, the clearance cold side should be .009" -.012" from the minor to the major, hot side .016" from the minor to the major, that will be both sides of the wheel on the minors. you may loose up to 15% efficiency for every .010" increase in clearance. I'd also run the measuring stick over the wheels just to make sure they are correct but I'm sure you you've already done that.

Sorry for the long post, something might be useful.
Thank you very much! Your knowledge and tests are all great ideas. I'm going to start working my way through them as soon as I can and the weather cooperates.
 
Also I forgot to mention that the injector pump delivery valves & springs play a big role in how the injector functions, I had a few fail (broken springs, worn valves) years ago on rebuilt pumps on fresh motors with catastrophic results (broken cranks, etc.) as the owners kept operating them. It lets the injector dribble & fart as gas & vapour forms in the line. Since then I have the springs replaced regardless and if the delivery valves are worn they are done too, parts are only about $50. A lot (read most) don't replace them unless there is an obvious fault cause there is no blast of high pressure hot gas against the test bench injectors blowing back past the needles. They really should be looked at when the injector nozzles need doing as the delivery valves do a similar amount of work. Not that you should rush out & get that done though.
 
Doug man. That's pretty freaked cold for no glow plugs. Wow.

It's pretty freakin cold for unheated leather seats too! I really want to get me a Webasto heater.

It was - 5c the other morning and it barley started with a jumper wire on the glow plugs.

Don't take this personally. But I think your engine is seriously retarded.
 
Don't take this personally. But I think your engine is seriously retarded.

Agreed if you don't find a leak on the compressed side.
 
Also make sure the washer under the injector is corect. If it's too thick the tip protrusion will be too close to the head and combustion is affected.
 
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I know lostih was and still might be having the same issues with this turbo, and his was a pulled un-touch runner. If I recall correctly.
 

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