Misfiring - Ignition Or Poss. Vsv?

[Muddy7]

Still trying to sort out a misfire on 96 RAV4.1

Having read a few references on the net to problems with VSV, I had a look at the Haynes book. Near useless.

I reckon that on our RAV they are up on an accessible bracket on the bulkhead (rather than bolted on the back of the block).

Left hand one is marked •1 and has two vacuum pipes at the top.

Right hand one is marked 32 and has two pipes but one at top and one at bottom.

Questions :-

Are they testable with 12v applied to terminals and which way should the vacuum 'divert' when "on or off"?

Can they clog up and therefore respond to cleaning?

Which one might be affecting the opening/non opening of the EGR valve (as I understand that can lead to misfires)?

Back to ignition.

Are the coil packs known to fail on these 3S-FE engines? - done about 110,000.

Thanks, especially if you can help ...

[Muddy7]

Still trying to sort out a misfire on 96 RAV4.1

Having read a few references on the net to problems with VSV, I had a look at the Haynes book. Near useless.

I reckon that on our RAV they are up on an accessible bracket on the bulkhead (rather than bolted on the back of the block).

Left hand one is marked •1 and has two vacuum pipes at the top.

Right hand one is marked 32 and has two pipes but one at top and one at bottom.

Questions :-

Are they testable with 12v applied to terminals and which way should the vacuum 'divert' when "on or off"?

Can they clog up and therefore respond to cleaning?

Which one might be affecting the opening/non opening of the EGR valve (as I understand that can lead to misfires)?

Back to ignition.

Are the coil packs known to fail on these 3S-FE engines? - done about 110,000.

Thanks, especially if you can help ...

Where have all the technical fellers gone?

Five replies already about stick-on wheelarches ...

[Davrav]

Still trying to sort out a misfire on 96 RAV4.1

Having read a few references on the net to problems with VSV, I had a look at the Haynes book. Near useless.

I reckon that on our RAV they are up on an accessible bracket on the bulkhead (rather than bolted on the back of the block).

Left hand one is marked •1 and has two vacuum pipes at the top.

Right hand one is marked 32 and has two pipes but one at top and one at bottom.

Questions :-

Are they testable with 12v applied to terminals and which way should the vacuum 'divert' when "on or off"?

Can they clog up and therefore respond to cleaning?

Which one might be affecting the opening/non opening of the EGR valve (as I understand that can lead to misfires)?

Back to ignition.

Are the coil packs known to fail on these 3S-FE engines? - done about 110,000.

Thanks, especially if you can help ...

Where have all the technical fellers gone?

Five replies already about stick-on wheelarches ...

Have you seen this thread Muddy? VSV No idea if it's helpful as have no familiarity with your engine. The technical guys are all probably doing the Saturday morning chores. I would think Bothy is your man for this one..............

[bothwell_buyer]

I looked at your problem .... and have had a think.... problem is I've cut down the whisky intake greatly as don't seem to have been so well recently. The reduction in alcohol made absolutely no difference other than plunging me further into the depths of despair :lol:

As you see, both my RAVs have the 3SGTE engine. One of them did suffer from a corroding coilpack which was mounted on the bulkhead - a replacement got the car running.

From my experience of the 3SFE, the misfires are often caused by the wrong plugs or old plugs fitted... a new set of sparklers would fix the thing. The other is to look carefully at the HT leads - as they will cause a misfire if old/corroded/cracked.

The 3SFE was fitted to other cars too and you might find some ideas by doing a search on the forum.

Is the misfire at all engine speeds? Hot and cold ? Is the engine getting to running temp ?

Have you cleaned out the petrol filter ?? Worth looking at, at a car this age.

[anchorman]

Problems with the EGR are rare on a petrol. The VSV as we refer to it are relating to turbo control on a diesel.

I will try to look at this later but will not get much time in the coming days.

Its the nature of a forum, maybe somebody else will answer but you can't demand it!

[Muddy7]

I looked at your problem .... and have had a think.... problem is I've cut down the whisky intake greatly as don't seem to have been so well recently. The reduction in alcohol made absolutely no difference other than plunging me further into the depths of despair :lol:

As you see, both my RAVs have the 3SGTE engine. One of them did suffer from a corroding coilpack which was mounted on the bulkhead - a replacement got the car running.

From my experience of the 3SFE, the misfires are often caused by the wrong plugs or old plugs fitted... a new set of sparklers would fix the thing. The other is to look carefully at the HT leads - as they will cause a misfire if old/corroded/cracked.

The 3SFE was fitted to other cars too and you might find some ideas by doing a search on the forum.

Is the misfire at all engine speeds? Hot and cold ? Is the engine getting to running temp ?

Have you cleaned out the petrol filter ?? Worth looking at, at a car this age.

Go steady on that whisky ...

Have so far only changed the plugs for a correct set of NGK's - Bosch were fitted.

No codes on diagnostic 'box'.

Took off one vac pipe to throttle body and cleared blockage in tiny drilling into butterfly area.

Does it hot and cold.

Does feel like a coil/lead misfire. If you zap the throttle open there is an audible stumble but move higher up the rev range it sings. Driving gently there is not much hesitation - but put the system under load and it misses and you get the odd pop and backfire in the airbox. Sounds like classic ignition but there again I've never had a car with so many vacuum pipes and devices or with VSV's.

Haven't changed fuel filter yet but as it pulls so well when the revs get up to 5,000 rpm I thought it might be coping - but have got one on order.

[Muddy7]

"Its the nature of a forum, maybe somebody else will answer but you can't demand it!" anchorman.

-----------------------------------

Sorry if it read as a demand!

Perhaps just a slightly more desperate plea for help as SWMBO thinks I can work miracles and wonders :-

"what the hold-up is ... with this nice reliable Toyota you have given me to drive." There isn't a sarky tone emoticon is there?

[anchorman]

If you take one of the old plugs and fit it to each of the plug leads, does it snap on really firmly or are any loose or signs of burning?

Is it a continuous miss with every turn of the engine or an intermittent miss that causes hesitation and jerking?

Can you see any arcing in the dark (sometimes you can hear it)?