1ggze running rough at idle

[masterofsinanju]

This morning while I was checking the oil I noticed that the charcoal canister inlet and outlet had come free of the canister body. No big deal, I'll drop a new one in.

However, this afternoon when I started up to drive home, it didn't catch first time and there was a small pop like a bit of blowback. It then started easily enough but seemed to be missing a bit and the idle was ragged and unstable, stalling a couple of times unless I stayed on the throttle. Otherwise it drove just fine except the throttle seemed a bit more twitchy between on and off.

I thought it might be something to do with manifold pressure and that it would be resolved when I whacked a couple of bolts in the hoses that were connected to the canister.

Idle is now stable but the engine still seems to be missing at idle although it smooths out under load.

Tonight with the hood up I did also notice a hissing noise which is coming from the front near the airbox and I cannot tell where it is coming from.

I don't recall the sound previously and it's very reminiscent of a high pressure leak.

The only thing I can think of is perhaps the misfire on startup has cracked an injector seal.

Anyone got any suggestions for diagnostics before I just drag it off to a mechanic who probably has even less idea than I do?

[dumbass]

check connector plugs on coils incase u have dropped a coil

[masterofsinanju]

Thanks Dumbass.
It doesn't look like anything is out of order there.

I'll pull plugs at some time in the next day or so to see what things look like there.

Idle is still rough and rises and falls by about 300rpm and throw the odd stall in. Feels like rpm drops off and gets a little blip before dropping off again.

EDIT: looks like the age old "vacuum leak" but stuffed if I can find it. I'll replace all the hoses and clean the ISCV again.

[mic*]

It does sound like the age old vacuum leak. I cannot say how the canister situation might relate, but perhaps check the air bypass valve for the SC is functioning properly. If one was to disconnect the wiring connector for the VSV which controls the vac signal to the ABV, I fancy I recall that it caused symptoms something like what you are describing.

The VSV is at the SC from memory, but just trace the vac line from the ABV to be sure.

If you do this and nothing changes, I would be inspecting the ABV system more closely.

Hope that helps.

[masterofsinanju]

Thanks Mic.

After a closer look, the canister appears to be labelled for a carb engine (looks a bit like the 18rc unit) and perhaps suited for lower pressures? Doesn't matter now. Got one from an st185 celica which should fit just fine.

I'll follow up on your thoughts about ABV.

[masterofsinanju]

So mic, did what you suggested and...voila!



Following this back does indeed end up at the SC as below



The line runs across the top of the engine/camcovers and down behind the SC.

But I have NFI what the other end in the first pic is meant to plug into. There is nothing obviously vacant for connecting to.

I've blocked it off for now and idle is much better, but I don't expect this is how it is meant to be and I can't find any diagrams that show me what I should be looking for but I suspect it is meant to go into the airflow metter somehow.

Any ideas?

[masterofsinanju]

After a closer consideration it looks like idle is fine when the engine is cold. he miss only appears once the engine reaches operating temp. I'm thinking one of the coils or plugs is knackered.

However, I'd recently started using a fair bit of coolant, so I did think head gasket blown.

But, there is no indication in the coolant of a BHG, no bubbles, no froth and no indicator of CO2 after a TK test.

So I think I have two problems that are unrelated.

Is it possible to pass a TK test and still have a BHG, particular of the type that might cause a misfire? My reading of teh webz is no, this is not possible. Any coolant leaking into cylinders would leave CO2 in the coolant.

I've yet to pull the coils and plugs to see what they look like.

The car wobbles at idle like I'm still rockin' an 18RG.

[G0TR1C3?]

Mate I have a 1G-GTEU and having the exact same sounding issues pretty much. Hopefully you find out what is wrong before me and then I am able to copy you haha if I solve my problems before you will let you know the steps I took.

Hope it all turns out for the best mate.

[masterofsinanju]

Thanks mate. You've also got a possible distributor issue to look at. The 1ggte has a distro setup that has two rotor buttons (there are two circuits in the dizzy and the rotor button contacts one of these at each end) and this means it could malfunction in a way that affects only 3 cylinders.

[mic*]

Hey mate did you ever get this sorted? Sorry for the super slow reply.

I have a vac diagram for the VSV / ABV / TB / SC / ABCDEFG lying around somewhere, I will dig it up if this is still giving you grief.

I am pretty sure your idle trouble will relate to that open ended vac line in your pic, but I could not make out exactly what I was looking at, I just agree that is isnt meant to be like that. The fact that it does not do it when cold is unsurprising because GZE is uber rich when cold.

As far as the coolant situation goes - inspect the water pump. There is a little hole at the bottom of the casing where coolant evaporates / leaks from when the seal is failing.

[masterofsinanju]

Hi Mic

It turned out that I had done a head gasket. All fixed now and the future paint fund is now zero.

I'd love to see your vac diagram if you can easily lay your hands on it as there are intermittent idle issues (but no miss).

[mic*]

Not exactly what I recall, but best I could find. (12 pages)
It says its about the 4A variant, but the vac system is engineered the same on the 1G, and S/C's are identical except for size.
The res was the best I could get that Toymods would allow to upload. If you want better quality PM me.

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[mic*]

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[mic*]

Hmm... seems I exceed some sort of quota and can't get the last three pages up...

I'm not sure whether the above attachment links will continue to work if I remove them from my "home folder" within the manage attachments button below (on advanced posting) ???

[masterofsinanju]

Maybe upload them to Imgur or similar and load onto forum from there.

In any case, they are great many thanks.