strange starting problem

Hi everyone, I've got a strange starting problem on my cruiser (90 series with the 1KTZT-E). So here goes...

Whether it be hot or cold, it would take a good amount of cranking for her to fire. I would average around 6 seconds of cranking, which is a lot in my book. One time it took twice as much. Once started the idles smoothly and drives as normal. I took her for a quick spin to walmart and did some shopped. 20 minutes later, I was cranking in periods of 5 seconds about 5 times before she finally fired. Anyway, I drove back on the motorway this time to see if she would struggle. Got up to 90 well and held it around there. I felt a miss at one point as if the engine took in a gulp of air. If I shut the engine off and start it back within 5 seconds, she'll start pretty much on two cranks. Any longer than half a minute requires a bit more and then after a few minutes it gets worse...You get the point! So, I've done the following so far...

- Looked at fuel lines and repaired anything that looked bad.
- Checked glow plug relay, circuit and actual plugs (I removed them, and bench tested them)
- put clear hose lines on inlet and return line. Originally I saw bubbles being sucked in and exiting. I ran it straight bypassing the fuel filter housing and no bubbles on inlet and pretty clear on the outlet. (Occasional small bubble) After this, I really thought I had fixed/found the problem but still no difference.
- Strong batteries and engine turns over well.
- I had a spare Injector pump (New) so swapped this over but same problem persist.

I'll be checking the compression tomorrow to see if that's below where it should be, but other than that, does anyone have any ideas? I'm a bit stumped!

Beau

Have you checked the usual corrosion on the pipes entering around the top of the fuel Tank?

Look to your primer i cured this by pumping it in a rage about 30 times after a garage took it upon themselves to change the fuel filter without being asked to .

I've dropped the tank and yes, there was some corrosion, as well as a couple rust spots along the actual lines. All this repaired/replaced with copper lines and now there are no air bubbles coming in from the tank side. Air seems to be entering a little through the primer pump so I bypassed that and ran straight into the IP. With the amount of priming I've been doing with the primer pump, I think I've killed it!

A bit of a update today. I have clear lines going in, and maybe 95% diesel, 5% air on the return. This aerated fuel is apparently normal with diesel, or should this line be solid? It starts a little better, but still requires about 6 seconds of cranking when left for long periods. Will be checking compression now, as well as timing again.

Also no fault codes thrown of CEL. I am puzzled! It's as though there is no pressure in the pump or lines when the engine turns off, as though the fuel drains back to the tank.... But with the clear lines in place I can see that it stays solid and doesn't appear to drain back. I also noticed that the main fuel coming through the return line banjo is off the actual pump, and the actual injector line return is just dribbling fuel under no pressure, is this normal?

Crank position sensor going?

What about the fuel cut off solenoid that Craig bypassed at the top rear of the engine , i blocked off the vacuum pipe running to them from the engine but it made no difference on mine ? worth a look anyway .

I unplugged the Crank position sensor and she wouldn't fire and also threw a CEL, is this enough proof to show it's working or is it worth pulling it out and replacing?

Not too sure about this solenoid you speak of Shayne? The only solenoid at the back of the engine I know of is a vacuum operated start up solenoid that opens and closes the small butterfly valve, which is working.

Now I did the compression test and got some very low readings, not too sure if they're correct though as I did it with the engine cold, and then realized I should have done it with the engine around running temp.

Cylinder 1 - 280, 2 - 190, 3- 210, 3 - 200. All these readings way below the minimum standard which is 280. I poured some oil down into the chamber and compression improved around 50psi per cylinder. This would indicate piston rings are a little worn. However, I'll be checking the compression again with the engine hot and see what difference I get.

I'm still a little puzzled because the truck drives so well, pulls hard, doesn't smoke, doesn't idle rough or make any usual sounds. Just being a pain when starting...

I re-checked timing today and all is spot on. I think the crank position sensor may be next in line, maybe it's faulty?

Thanks guys!

I don't know if there is a test as such for the sensor other than swapping another one in, no idea if you have a spare but I seem to recall that they are rather pricey.

Trevor said:

I don't know if there is a test as such for the sensor other than swapping another one in, no idea if you have a spare but I seem to recall that they are rather pricey.

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hmm I wonder if they were used in different Toyota engines? Because obviously the local part store hasn't got any 90 series diesel parts here haha

Maybe the 80 series CPS is similar? Time to do some research!

I've just done a parts lookup on toyo, 90910-09087 is used on pretty much all and any North American Toyota so you should get lucky at a breakers.

I seem to have found a different part number - 90919-05005 hmm

Beau said:

Not too sure about this solenoid you speak of Shayne? The only solenoid at the back of the engine I know of is a vacuum operated start up solenoid that opens and closes the small butterfly valve, which is working

Click to expand...

Thanks for that Beau twice i've been told it was something to do with fueling and i could never work out why , i guess i can remove that lot of jumble as well then .

Just a thought - you are now running on American diesel which very likely has cheese in it so might that be something to investigate .

Shayne said:

Thanks for that Beau twice i've been told it was something to do with fueling and i could never work out why , i guess i can remove that lot of jumble as well then .

Just a thought - you are now running on American diesel which very likely has cheese in it so might that be something to investigate .

Click to expand...

There diesel did cross my mind but I kinda doubt it... Once she fires she runs as normal.

With regards to the solenoid, it opens up the small butterfly in the intake allowing some air through the intake on start up and closes on shut down, to smooth down the shut down. If you listen you'll hear it click/hiss as it operates on start up and shut down. If it's working, there's probably no reason to remove it, why are you thinking of removing it?

I clamped mine with molegrips as an experiment when Craig said disabling it made a difference to his but got no result at all , plus they were originally bolted to the throttle body pipe which i removed to fit the intercooler and i have never got around to making a bit of a bracket to keep them tidy but if its all just junk serving no purpose it may as well be removed .

I'm thinking its due to your low compression readings, you could crack the fuel lines at the injectors and observe the fuel being delivered whilst the engine is being turned over.

Well my worst thoughts have been confirmed today, with a leak down test...

I pumped about 120 PSI into each cylinder through the glow plug hole, whilst each piston was on TDC, so no valves should be open. Took the rocker cover off as well to confirm this. All cylinders are leaking. Not a happy day.

Cylinder 1 leaking out of Exhaust valve.
Cylinder 2 leaking into Cylinder 1 and possibly intake valve
Cylinder 3 leaking through Intake valve
Didn't even bother testing cylinder 4.

Looks like the valves aren't sealing properly and the head gasket is also blown. This would explain the low compression readings I go, as well as the starting issue. I'll pull out the head this weekend and inspect the head. I suspect the head will probably be cracked as well considering Toyota head's are crap. If that's the case, AMC head it is. Unless someone has a good head lying around? I can't believe one busted hose has led to this.

I'm surprised she runs so well considering the internal damage

P.S I wonder if a Ford V8 6.0 diesel powerstroke will fit in the engine bay....

I can't imagine how disappointed you must feel after all the effort to get her there but you've fixed her before and you will fix her again and that's what makes it your truck .

Well I took the head off today. Second time I'm doing this so it ended up being a piece of cake. 3 turbo bolts, rocker cover, top manifold and various vacum related stuff at the back off. AC pump to the side, timing belt off as well as casing behind it. Undo head bolts and off she comes.

Now, I was expecting cracks everywhere, but to my surprise the head on the initial look, looked pretty good. Only two pre-combustion chambers were cracked which is apparently pretty normal with these heads and shouldn't affect the compression, at least I think so? There are no visible cracks in between the cylinders. On cylinder 3 there is a very small crack between the valves which isn't all the way across. Anyway, I checked the head with a ruler and it looks warped. Mainly cylinder 2 and 3. I didn't have a feeler gauge on me so I used a Stanley knife. I would estimate that there's between 0.5-0.75mm gap accross the two middle cylinders, and 0.5mm on the sides. It did cross my mind to resurface the face, and use a thicker gasket, but that's now a guaranteed fix.... so I'll be opting for the AMC head and 5 hole Gasket.

And the Gasket was definitely blown. It even broke/chipped on the inside edge of cylinder 1. Very strange, looked as though someone took a bite out of it.

Ok, so if I was to resurface the head, how much can I remove before the heads no good?

I don't know the figures off my head (no pun intended) but a decent machine shop should actually be able to tell you how much they can take off.

I've got to say though Beau, from your photos that looks proper warped, not just a teeny weeny bit warped and if the photos do justice I'm afraid I'd scrap that head and go for an AMC replacement without wasting the cash on trying to get the original skimmed.