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Z24E running too rich. update:now a loud rattle noise, rod knock?


Spiff

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Hello, I have converted a Z24 carburetted engine to EFI using the efi setup from a Z20E engine. 

Initially I had trouble getting it to run because of a couple of clogged injectors and weak spark(engine didn't wanna accelerate, only idle and light load, then fouled the plugs and died after a couple of miles.) So I replaced the water temp sensor and afm. That didn't do very much. The afm helped a little but the sparkplugs where still not able to fire good enough for it to run properly.

Yesterday I got my new NGK spark plugs I had ordered and it fired up and runs very good except for an odd misfire at idle(but never when driving). 

But its still running very rich, carbon build up on the plugs, so before I start adjusting the afm; Can the fact that I'm still using the points distributor and coil with resistor contribute to an uncomplete burn? The Z20E engine uses the "matchbox" type electronic distributor but I weren't able to obtain that when aquiring the z20e parts so I have ordered a pertronix ignitor and flame thrower coil but haven't gotten it yet...

Also this is a european engine, so only 4 sparkplugs on this head. 

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First you're asking a 2 liter set up to handle a 20% larger displacement. That's a lot more air going through the AFM. A guy on here tried this I believe but he doesn't post much.... http://community.ratsun.net/topic/10507-welcome-sealick/ . May be in here somewhere... http://community.ratsun.net/index.php?app=core&module=search&do=user_activity&mid=2344

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First you're asking a 2 liter set up to handle a 20% larger displacement. That's a lot more air going through the AFM. A guy on here tried this I believe but he doesn't post much.... http://community.ratsun.net/topic/10507-welcome-sealick/ . May be in here somewhere... http://community.ratsun.net/index.php?app=core&module=search&do=user_activity&mid=2344

 

Yeah so I would expect it to run leaner because of the increased displacement, but now that you mention it maybe the afm needs adjusting because of this.

It's just that several years ago I had a bluebird 910 with a z20e engine and the previous owner had swapped the block for a z24 block and a turbo setup. That ran fine, no overfueling or anything, so I expected this to do the same. 

I have a wideband A/F gauge but I need to take care of an exhaust leak before i fit it, probably gonna be easier to tune with that.

 

But will an overly rich idle cause the random misfire/stumble at idle I mentioned? 

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I've started to notice some blue smoke, so I'm pretty sure I'm burning oil. That maybe why the sparkplugs are black also. Anyway I did a comptest and the results where:

 
190 180 200 190 PSI
 
factoryspec is 171 with 128 as minimum. Any tips as to why I'm still burning oil? PCV valves?
 
 
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Over rich is washing the oil off the cylinder walls and burning it.

Valve seals shot

Over filled with oil

 

Interesting proposition and one I'm gonna have to look into. But untill I get my new manifold gaskets it's pointless to install my A/F gauge as I think it'll read false because of the exhaust leak.

 

 

Yep^^ happened to me with too big a carbs. So bad the oil turned gray. So what in the system control fuel? (o2 sensor or what)

 

The efi system is a bosch L-jetronic. No O2 sensor. 

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Today I got my pertronix igntitor and flame thrower coil. I got that dialled in then turned my attention to the throttle position switch and it wasn't indicating when the throttle was closed so the ecu didn't have an idle signal. Adjusted that correctly but still had the odd missfire on idle so now I turned my attention to the idle CO screw on the AFM, I thought it was running rich so I adjusted it out which should lean it out but that didn't really help so I turned it in quite abit and then the misfire went away and the engine idled perfect!

 

So I went for a test drive and about 2.5km's I slow down for a pedestrian crossing the road and after that I floor it in second gear and just as I'm about to engange 3rd this loud rattling noise appears! So I limp home to the garage and it sounds like something is loose in the valvetrain so I check valves for clearance and check the chain for slack but everything is okay.

Sounds horrible and the engine is clearly not happy, shudders and shakes. I'm wondering If I might have developed a rod knock. Its hard to tell where the sound is coming from, its like everywhere! And its loud, sounds like shaking a metal toolbox full of wrenches! More loud with more rpm's but just above idle it's more quiet(somewhere around 1-1500rpms I would guess, I don't have a tach)

Also if I put my foot on the clutch pedal I can feel vibration. Pedal in or out doesn't matter.

 

Can the screwdriver on piston method be used on the Z and L engines or doesn't it work since the sparkplug holes are on the side of the head?

PS: I should also mention, in keeping with the previous posts about oil burning, today when I started it up first time after standing still for two days there was a big puff of smoke, I think that might be indicative of a valve seal or guide is leaking as clearly oil is entering the cylinder... But that's not the biggest consern now though.....

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Well not the rods I think but something moving is loose or broken.

 

Loosen fan belt and spin the alternator then the water pump..... ok?

 

 

 

 

Have you had the cam sprocket  off? Changed the timing chain? Replaced the head gasket???

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It was something loose indeed, the flywheel bolts had come loose. That's the good news,the bad news is we didn't figure that out before we had moved all the ancillarys over to the spare motor... But as mentioned previously in this thread it did burn oil so I'm gonna get a rebuilt head and check pistons and cylinders while it's out

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Lucky they didn't shear off. Did that with my L20B swapped 521. Engine sat outside and the threads got rusty. I torqued them down properly but the rust caused them to tighten up too soon. As the engine was shut off and no way to start it I drove it a few blocks in second gear using the starter. 

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