1hdt fuel solenoid (1 Viewer)

[franklin40]

to increase fuel with the main screw is it a clockwise or counter clockwise turn

edit. clockwise turns fuel up. i had to get it 1/2 turn then 1/4 turn then 1/8 turn before i could get a puff of black smoke. holy cow that was under fuelled. i still need to play with boost compensator and check for boost leak. i still can’t get it to boost up to 20 psi. only 14

 

[franklin40]

well maybe a new development here. i can’t get it to start cold now either so can’t even drive it to my diesel shop. while my wife is cranking is i have exhaust coming out the tail pipe but just not enough fire to get it to run. i’ve also developed a major oil leak between the block and girdle which makes me wonder if i’ve got some internal issues leading to lack of compression. i may be on the rabbit trail of a whole rebuild

 

[franklin40]

compression test not looking too hot.

now this is a cold engine because i can’t get it to start so that’ll likely affect some stuff but here’s what i got (newish gauge but don’t know if accurate either). i do know that when it was running well i had done a compression test and my numbers were lower than expected when warm with this gauge and it would fire in -30C with just a glow so i’m sure my compression was probably better than what the gauge said but i don’t know for sure

1-300 psi
2-300
3-240
4-275
5-250
6-240

i don’t have the tools to do a leak down but when i left the compression gauge connected it would loose about 20psi in each cylinder over the first 15 seconds then stay put without loosing any more pressure. seems like my valves are seating ok but i wonder if i’ve got worn rings as i don have some blow by

 

[mudgudgeon]

i don’t have the tools to do a leak down but when i left the compression gauge connected it would loose about 20psi in each cylinder over the first 15 seconds then stay pu

Pretty sure you can add a 1/2-1 teaspoon of oil into the cylinder, redo your compression test. If that initial drop in pressure goes away, rings are your issue.

What's the FSM compression spec? My memory is 550psi??

 

[mudgudgeon]

Close. 500psi or more. Lower limit 356psi

 

[franklin40]

min 350ish but should be 490ish

maybe i’ll try adding some oil tomorrow after the batteries have charged again

should i have all glow plugs out at once to really let the engine spin? or just one at a time?

 

[mudgudgeon]

I'd take them all out so the engine turns over easier. Battery won't run down as fast too.

 

[OPUS1]

The fact that it starts relatively easy in minus 30 would suggest low compression. Those numbers are really low if they are I/2 of standard spec - maybe double check with another tester? Did the engine suffer some abuse prior to your ownership? Seems like a lot of wear for only 550k on a Toyota diesel.

In any case the low compression shouldn't be the reason for the original problems that you were encountering with the engine dying.

 

[franklin40]

i’ve been told that tight valves could cause hot start issues. i did adjust my valves this spring (but put them all back in spec). could that change along with a worn engine have caused my issue? i don’t know. they are all in spec now though. they weren’t before. i’m going to repeat compression test tomorrow with all glow plugs out at once and i’ll also do it a second time with some oil to see if it makes a difference. i just don’t know if playing with things to try to tune it up made a worn engine not work right? i don’t know if that’s a real thing. it seemed to run fine after valve adjustment and actually got 10% better fuel mileage so hard to believe that would have made an issue. i’m just trying to think of what might have changed around when i had issues as i’m kind of out of other ideas. low compression in cold weather would make for harder starts wouldn’t it? more compression is needed to get the fuel to ignite

 

[OPUS1]

I don't think setting valves properly would hurt - more likely help. Lower compression - spins twice as fast - builds more heat then fires. High compression is good if engine starter speed doesn't get dragged down by the cold -30! Also some diesels seem to just cold start better than others - my cummins ( first gen ) and perkins diesels are the best cold starters I have by far.

 

[mudgudgeon]

I don't think setting valves properly would hurt - more likely help. Lower compression - spins twice as fast - builds more heat then fires. High compression is good if engine starter speed doesn't get dragged down by the cold -30! Also some diesels seem to just cold start better than others - my cummins ( first gen ) and perkins diesels are the best cold starters I have by far.

The 1HD-Ts typically start on the first compression stroke. Bump the starter and they go.
I'm not sure your lower compression theory holds up in this scenario. Regardless, compression numbers are not good

 

[franklin40]

I redid the compression test tonight with all of the glow plugs out at once. Cylinder six was 440, cylinder five is 420, cylinder for was 420 cylinder three was 440 cylinder two was 400 and cylinder one was 440. That makes a lot more sense to me and she was at my engine is actually not all that unhealthy. It Must have something to do with timing or fuel tuning or some electrical grandma that I just can’t figure out yet but at least I don’t think I need an engine rebuild at the stage. those numbers were with no extra oil in the cylinders!

 

[OPUS1]

those are good numbers and within 10% variance which should be acceptable

 

[franklin40]

really amazes me the difference in number when the rest of the engine compression is taken off but i guess it fits the fact that compression is good by these numbers. now back to the drawing board to get it to run.

still taking it to a diesel shop monday to have them tune and time this beast!

 

[franklin40]

well a new update. i think i’ve figured it out. and it was likely a simple oversight.

i put it all back together tonight after the compression test and again it wouldn’t start so i thought k let’s try the jumper technique to the solenoid and see what happens. started.

so as i mentioned earlier i did test for 12 v at the harness but i think i only did this cold. i’m not sure i ever did it when it was hot but can’t be sure. in either case i think what’s happened is that the old wires in my ignition harness may have a break or corrosion that when they get warm it’s enough of an increase in resistance there isn’t enough power to open the solenoid. of course as soon as i had it running i drove it to the diesel shop so i didn’t have to trailer it. when i got there and it was hot i turned it off and tried to start it. no go. jumped the solenoid right off the battery and vroom started right up. so yeah there we have it. i believe for now it’s an electrical issue i’ve gone back and forth on so many possibilities i think i just missed trying this and of course it’s the thing that worked.

while it’s at the shop i’ll get them to do a timing and performance tune on my pump and then i’ve got to figure out my oil leak.

i’ll keep things posted as i go with the wiring fix! still glad to have the pump and injectors refreshed. it was time anyway

 

[franklin40]

another update the shop rewired the solenoid as it seems to have fixed the problem. they still have some tuning to do so they’ll watch it when hot and cold to make sure it keeps working. monday the they’re going to do the pump tune and i’ll have it back. i need a new starter apparently. it’s pulling a lot of amps and getting hot very quickly. may have been part of my lack of electricity as it was all going to the starter. so i just ordered a new one from 4wheel auto. kind of pricey but it’s brand new and a gear reduction starter. should be good for the cold starts. he suggested that a reman one will save a couple hundred bucks but they don’t have new stators in them. this one is fresh and new and should last me another 30 years.

 

[franklin40]

so mystery solved. bad wiring that was intermittent was the issue. the shop then turned the fuel screw almost to the max and that brought it back to life. simple fix in the end but just odd enough it had me chasing my tail in the worst way. now i have to fix the wiring the shop screwed up when they “fixed” the solenoid wiring. my one headlight now flickers and my rear back up lights don’t work at all!! oh brother. so it goes. these are never ending projects. i just like the ones i can deal with while still driving the vehicle!!

at least this thread has a happy ending and i’m glad to be driving my truck again!!

 

[mudgudgeon]

Awesome to finally get a result!

 

[franklin40]

yeah for sure. but now as we speak i’m stuck in a parking lot because my starter is too weak in the cold. COME ON!!

at least i can diagnose that and fix it easily. and i’m hoping to have a new starter tomorrow. gotta bump start it tonight when i get an extra body to drive while i push. i half expected this to happen so i parked at the top of a hill in the parking lot!!

 

[mudgudgeon]

Murphy's Law huh!