Fitted New Spark Plugs .. Now It Misfires

[Cexy_Ratt]

Well though i would be nice and buy some new sparks for the 4, it used to misfire a little in the mornings etc.. so thought it wouldnt do any harm. I got the Denso platinums from toyota ( got a discount !)...now is misfires, doesnt seem to rev under boost..

i have check all the plug leads out and all seem ok, gonna use a gap tester on them and see what the spark gap is like on all the spark.

Anybody had any problems witht he denso plugs, it had NGK R platinums in before.. they all look grey/ white, is it worht putting them back?

[Cexy_Ratt]

Ordered some magnecor leads from fennies, but after reading GT4OC probably shouldnt have bothered, people seem to have a bad time with these leads, should i be cancelling my order? - wel lthey arrive tommorow. They cant be tbad can they?

[ricomr2]

Did you gap the plugs with feeler gauges to the correct spec before fitting them?

[Sketchy]

Ordered some magnecor leads from fennies, but after reading GT4OC probably shouldnt have bothered, people seem to have a bad time with these leads, should i be cancelling my order? - wel lthey arrive tommorow. They cant be tbad can they?

There where some issues when magnecor originally produced the leads due to the unusually ignition coil plug and the fact they where trying to create one kit to fit all the 3s-gte engine cars. Which has tainted a few owners with regard to magnecor products.

This has since been changed and different car specific kits are avaliable, I've got magnecor lead on my car and have no problem with them (Fitted by previous owner)

It very much seems to be that on the GT4OC with some people once they've had a bad experience they don't really get much of a second chance, I've used magnecor leads on previous cars I've owned and never had any problems with them, they always worked much better than the stock leads.

The only thing I would say is that unless your going for the KV85 competition leads you probably better off sticking with the stock toyota leads as the 5mm magnecor leads seem no better athought they are slightly cheaper...

[Cexy_Ratt]

Right guys, really stuck with this now, when the car gets to say 4.5+ rpm, it just splutters, doesnt pull, kinda misfiring. I have put the orginal plugs back in and the same fault occurs.All the leads re in the right order, it runs fine untill you get to 4.5k on the revs.

I checked the leads out with a gap tester and they are producing lots kv's. Really stuck now, car is pretty unsuable, no engine managment lights are coming on, Dump valve is dumping away whilst driving so is making boost

Any ideas what i should be loooking for doing?... its my every day car so i need it sorting asap

thanks in advance

Rob

[daktari]

Have you checked the lead connection at the coil. My original Toyota leads were rotten when i got the car and this was the main one at fault. When i pulled it out, the end was left in the coil. Incidentally, I replaced with 8mm Magnecor leads. Not had a problem with them.

[Cexy_Ratt]

Well the new leads arrive tommorow, so hopefullt they will cure the fault, as the problem wasnt there before i un hooked the leads to change the plugs( incedently are denso ones from toyota). I have just reset the ecu and will see how it goes tommrow.

Really hope it sorts the problem out, becuase i love this car and it depresses me when it goes wrong.

Will update tommorow

Also is the fuel filter hard to change , gonna give thata whirel aswell

Have you checked the lead connection at the coil. My original Toyota leads were rotten when i got the car and this was the main one at fault. When i pulled it out, the end was left in the coil. Incidentally, I replaced with 8mm Magnecor leads. Not had a problem with them.

[Sketchy]

Well the new leads arrive tommorow, so hopefullt they will cure the fault, as the problem wasnt there before i un hooked the leads to change the plugs( incedently are denso ones from toyota). I have just reset the ecu and will see how it goes tommrow.

Really hope it sorts the problem out, becuase i love this car and it depresses me when it goes wrong.

Will update tommorow

Also is the fuel filter hard to change , gonna give thata whirel aswell

Have you checked the lead connection at the coil. My original Toyota leads were rotten when i got the car and this was the main one at fault. When i pulled it out, the end was left in the coil. Incidentally, I replaced with 8mm Magnecor leads. Not had a problem with them.

Yep Denso is the stock toyota stuff.

Could try checking the base timing incase you somehow managed to knock the dizzy out when changing the leads/dizzy cap???

Fuel filter is pretty easy just watch out for seized connector and use 2 spanners 1 to hold the filter stationary and the other to undo the connection in a kind of closing sissor action...

[Cexy_Ratt]

Will get my dad to check the timing for me, ( in house mechanic, likes to make me fix things myself usually ), also i didnt change the dizzy , it was replaced not so long ago by the prev owner

Hope it sorts it out,

The car is fine untill it gets onto full boost , starts fine, no hisses or vac leak noises. no backfiring, just seems to ( crap sounding word) > Brughhhhhh, then kinda gets over it and brughh again, untill you come off gas or change gear.

Doesnt do it whilst idling > all thought he idle does seem to dive and go up between 900 rpm and say 750 ish...

Sorry if i am spamming but just really confused by how changing the sparks has doen this, incidently the orginals are now back in> and the same fault

[Sketchy]

Might be the connection in the coil lead like dak suggested, try fitting the new magnecor leads when you get them and see if that makes any difference.Could also be a iffy spark plug connection.

Fitt the new leads and see what's going on then

[Cexy_Ratt]

All sorted now, running great again. Must have been the old toyota leads, mind you they are probably the orginals so 15 years isnt to be scoffed at.