Advice needed

[Daveo 2003 3RZN154R]

Hi All, im dave from carrum downs. A mate who is a mechanic and I, who isnt a mechanic and with basic car knowledge. We installed a turbo into my 2.7ltr 2003 Toyota hilux 3RZN154R engine, ever since we got it going its been miss firing, back firing, running lean to sparkplug loaded with carbon. Everything but running right. Can anyone please help. My mate has told me the engine has changed the firing order to the downstroke would it change the engines firing order to its exhaust downstroke. I don't understand if or how this could be possible. We have tried everything almost. From fuel pressure regulators to about to install a distributor. To buying and about to install haltech 750. Im in need of some good advice to understand where we have gone wrong. It would be greatly appreciated. 

✌️ Daveo

[Hiro]

12 hours ago, Daveo 2003 3RZN154R said:

My mate has told me the engine has changed the firing order to the downstroke would it change the engines firing order to its exhaust downstroke. I don't understand if or how this could be possible

 

On the surface it sounds like total nonsense, but there is a kernel of possibility in there.  Firstly, firing _order_ is a function of the distributor cap and the spark plug wires, but to run right it relies on matching the order in which the camshafts open/close the valves and the crankshaft moves the pistons up/down.  If none of those things have been changed as part of the turbo install, then firing _order_ isn't the problem (standard for a 4-cylinder is 1-3-4-2).  Confirming your leads are going to the right spark plugs is a quick and free check though, and an easy thing to stuff up when putting everything back together if you were forgetful/distracted.

Ignition _timing_, on the other hand, is what you would be looking at if the diagnosis was that the engine was firing on the downstroke.  Normally, ignition timing is set to fire the spark plugs just BEFORE top-dead piston centre (ie, on the compression upstroke, this is called timing ADVANCE), so that the combustion occurs at the very top of the cycle to impart the most downwards force to the piston.  If the ignition timing is completely out, then the spark plugs might be firing AFTER top-dead centre (timing RETARD), which will make the engine run like a bucket of bolts and also incredibly rich.  Get a strobe and see what the timing is doing.

However, the fact that you're contemplating installing a Haltech makes me think you've done this turbo upgrade without touching the factory computer, which in reality is most likely to be the culprit.  Whilst it can work in some scenarios, running more than a small amount of boost through an NA engine/computer without any other upgrades is a recipe for disaster, as the ECU doesn't know how to handle the extra air (or can't even measure it properly to begin with) and will just flail around trying to adjust.

 

Also, there is no "exhaust downstroke".  In a suck-squeeze-bang-blow 4stroke, the exhaust part of the cycle is an upstroke of the piston (to force the burnt gases out of the combustion chamber).  Intake (suck) = downstroke.  Compression (squeeze) = upstroke.  Power/combustion (bang) = downstroke.  Exhaust (blow) = upstroke.