Issues after Head Change

[Ben_D]

Hi All,

Changed the head on my Gen 3, over weekend. Fired up more or less first turn of the key but sounded a bit rough.

Things changed
Head & gasket, also gaskets for every bit removed
Oil & filter
Coolant, thermostat & rad cap
Timing belt, tensioner & idler
Fan belts


I have the following issues
Noisy top end on start up for first few seconds which disappears
Misfire between 1750 & 2000 RPM that seems to disappear when warmed up
Black smoke on start up (really quite bad) that goes once warmed up
Doesn't switch of instantly and shudders to a stop regardless of temp.

Drives & pulls OK however, and once warm sounds better than it ever did at idle. Today it would not start without the aid of some easy start.

Things I have checked.
Timing belt - marks are all bang on
Vacuum hoses checked for correct placement and for splits,
Correct fit of injector pipes
Injector pipes cracked - fuel to each
All plugs / electrical connections are secured and correctly fitted

Only non-planned thing during head swap was accidental loosening of an injector, rather than undoing the whole thing, I split one of them which was quickly torqued back up to spec.

Anyone got any ideas or had a similar issue?


Many thanks

Ben

[Rob5464]

How bad was the cracked head?
Did you pressure test the cooling system before you took it off?
what did the cylinders and bores look like?
Did you turn the engine by hand with the head off?

Sounds like a bent rod (speaking from recent experience)

[Ben_D]

Hi Rob,

Cracked head was about as bad as it gets! Definitely pressure in cooling system, bubbles in expansion tank and using alot of coolant, white smoke, all usual head symptoms

Bores clean & smooth, pistons fine. Timing marks lined up by hand prior to removing old head and not moved until turning the crank by hand to check timing after rebuild. Everything seesm fine with bottom end, I think in my case it is unlikely that I have bent a rod.


Cheers

Ben

[Ben_D]

Loca garage just hooked itup to diagnostics machine and it doesn't throw up any faults. The guy reckons it's clean in terms of codes however he used Prado data as he had nothing for the Surf.

Thinking it must be injector related?


Cheers
Ben

[Rob5464]

I don't think its an injector it shouldn't stop rough from that I wouldn't have thought. do a compression test. check you don't have a fuel leak from the filter, that would make it hard to start. What does the manual primer feel like?

[BUSHWHACKER]

Double check the injector pipes at the back of the fuel pump are fitted in correct order.

[wishbone]

Make sure your vacuum pipes actually actuate the butterfly on the inlet - if they're not working properly then it won't shut down properly. Also check the turbo pressure sensor - it's very delicate and easy to break.

[Ben_D]

I don't think its an injector it shouldn't stop rough from that I wouldn't have thought. do a compression test. check you don't have a fuel leak from the filter, that would make it hard to start. What does the manual primer feel like?

Thanks Rob, I'll see if I can get someone to compression test it, would lack of compression cause misfire & overrun? Fuel filter was not touched during strip & rebuild so I'd be surprised if it was leaking. Primer is hard to depress as it would be once pumped after a fuel filter change.

Double check the injector pipes at the back of the fuel pump are fitted in correct order.

Quadruple checked Vince. Presuming the cylinders are numbered front to rear 1-4 I have:
Lower O/S pipe to #1
Lower N/S pipe to #2
Upper O/S pipe to #3
Upper N/S pipe to #4

I presume that checking the Surf ECU with Prado data should be fine?


Cheers

Ben

[Ben_D]

Make sure your vacuum pipes actually actuate the butterfly on the inlet - if they're not working properly then it won't shut down properly. Also check the turbo pressure sensor - it's very delicate and easy to break.

Vacuum stuff all OK, Turbo sensor did get knocked a couple of times but looks sound. Are these cheap things? If so I'll look for one and change it anyway, can't do any harm.

Cheers

[wishbone]

Vacuum stuff all OK, Turbo sensor did get knocked a couple of times but looks sound. Are these cheap things? If so I'll look for one and change it anyway, can't do any harm.

Cheers

Did you check that it actually moves the actuator arm on shutdown ?

[Ben_D]

Did you check that it actually moves the actuator arm on shutdown ?

I didn't but I removed the intake pipe and checked that there was vacuum through the actuator when moving the small butterfly and pressing the pipe to my finger. Hope that makes sense!

Just had a look at the service manual on checking this, I will run through the procedure tomorrow.

Cheers

Ben

[Albannach]

When you say you 'split' an injector, exactly what do you mean?

[s car go]

I've been thinking about this,and I personally I think your problem could be in this injector. Actuators would'nt cause the rough shut down you describe(4 runners do not have any).
Assuming you bought an exchange built head, the rattling you describe is probably injector rattle,and not cam related,There's nothing else on the top end to rattle.Leaking/bad injectors cause black smoke,misfire,and rough shut down. My guess is you've done something to that injector when you loosened it!

Good luck

Mark

[Ben_D]

When you say you 'split' an injector, exactly what do you mean?

Hi Andy, I undid the nut that hold the injector together rather than undoing the nut that fastens thre injector into the head during a slight lapse of concentration. I torqued it back up to recomended, thinking that this could well be the problem.

Mark,

The head is a built AMC from roughtrax, checked the actuator this morning and all is fine on shut down. Needed Easy start to get it going in the first place though. Going to try to get some new injectors, thinking that as the truck has done 223000KM, and going by the crap in the inlet when I rebuilt that theoriginal injectors have probably seen better days.


Cheers

Ben

[s car go]

Ben
The crap in the inlet manifold is from the EGR system.Mine was caked as well.Best thing for the EGR is put it in the bin!!!!
Poor starting is normally the glow plug circuit,easy to short out when working on the head???
You could try a drop of atf in the fuel filter or if your low on diesel in the fuel tank.
If you've checked everything else,timing, plumbing etc then it only really leaves the injector,which as you said,got loosened in error!!

You did fit the injection nozzle seats ???

Regards

Mark