Real Fiero Tech

I've been trying to figure out why my car sounded like it hade a bit of a lope - and was very throaty along with some rough running issues I wasn't too concerned with as I am about to install high flow injectors and burn a new chip for it.

anyways - I went for a quick dive around the block and parked the car listening to the exhaust - decided to try pulling one plug wire at a time to see if there was one causing a missfire.

pulled #5.. odd almost no change in exhaust tone - no change in rpm
pulled #3.. odd same thing
pulled #1.. and oh shit the engine is bogging and it just backfired - so i plug it back in..

pull the plugs and what do i find but on the one head I was only firing off 1 injector

I'm amazed how quick it was for being down atleast 2 spark plugs..
now to go get some NGK's - i've probably put about 4 hours on these bosche platinum plugs - and they can kiss my ass

Left is as I pulled it -- middle was like left till i cleaned it looking for any sign of an electrode -- right was the only one firing on the rear bank



oh and you may think that looks like an electrode in the middle one.. but i assure you its only a shaddow - as far as i can tell the little platinum core burned out

Looks like your running very rich and possibly burning oil judging from the color of the uncleaned plug.
Is it just black and sooty or is there some charred oil on it?

I wouldn't be quick to blame the plugs as the single culprit, but changing the brands is a good idea. If nothing gets better, I would look into fuel system and any problems there.

Is the ECU pulling any trouble codes?

it had been running really rich (at idle anyways) part of why I was working on burning a new chip for it - however all the plugs should look like the one on the right.. they weren't firing enough to have any noticable change in the exhaust when disconnected

if its burning any oil its not coming through the intake because I have breather and pcv catch cans installed with no side of oil blow by

Valve seals then?

So you havent burned a new chip? I guess I would check the ECU for trouble codes, burn a new chip and if it doesnt get better, with new plugs.....come back here.

Have you listened to the injectors to make sure they're all cycling?

teamlseep13 wrote:Valve seals then?

So you havent burned a new chip? I guess I would check the ECU for trouble codes, burn a new chip and if it doesnt get better, with new plugs.....come back here.

couldn't - had to send the autoprom back ot moates for not working - i'll get it back soon i hope - burn my new chip and install the gtp injectors

then i can start turning up the boost

i don't think its burnign any oil

The Dark Side of Will wrote:Have you listened to the injectors to make sure they're all cycling?

(they are getting replaced as soon as i can burn my new chip)

I would stay away from anything BOSCH, I've had nothing but problems with their products.
Not sure, but stay away from any kind of Platinum plug. Its bad on a boosted( Sc3800 anyways) car. They stay hot and will create knock. Look into Autolites or NGK copper tip plugs. They are cheaper and safer then the platinums. I use Autolite 103's, but 104's should be good for your setup. Stay AWAY from Autolites "race" plug. Those are the biggest pieces of shit on the market.

PervertedHamster wrote:I would stay away from anything BOSCH, I've had nothing but problems with their products.
Not sure, but stay away from any kind of Platinum plug. Its bad on a boosted( Sc3800 anyways) car. They stay hot and will create knock. Look into Autolites or NGK copper tip plugs. They are cheaper and safer then the platinums. I use Autolite 103's, but 104's should be good for your setup. Stay AWAY from Autolites "race" plug. Those are the biggest pieces of shit on the market.

sweet - the 104's a colder plug?

I've heard reports of bosch's platinum pads disappearing as well. I stick with AC Delco parts whenever possible. Yes, they'll probably be $6 ea, but well worth it.

i've contemplated using torquemaster plugs again - I used them on my last 3.4 pushrod and they worked really well - but wanted to have a little more fuel and a slightly advanced spark -- dunno how they will work with a DIS system - they are like 12$ a plug

I always use stock Declo plugs with my engine ont eh nitrous. NO PROBLEMS AT all. I dont see the reasonign behind spending assloads of my hard earned money on a plug that wont' do jack shit moer then a cheap plug.

All those fancy shmancey plugs dont' provide more power hten a good stock plug.

maybe - but the torque master plugs were the same after 30,000 miles as the day I put em in (other than some slight coleration change fromt he heat)

The Bosch plugs should never be used with a 3.4l DOHC.

I'll find some of the articles later, but just fyi, don't use them. Something about them not being deep enough.

I use(d) AC Delco Rapidfire 8s on both of my 3.4s.

Aaron wrote:The Bosch plugs should never be used with a 3.4l DOHC.

I'll find some of the articles later, but just fyi, don't use them. Something about them not being deep enough.

I use(d) AC Delco Rapidfire 8s on both of my 3.4s.

more regurgitation babble from someone not so sure of why they shouldnt do it, just remember a internet report from reliable sources not to do it.

Ok dumbfuck, is ben (www.60degreev6.com) a good enough source for you considering he knows more about the 3.4 DOHC than anybody we know of?

AaronZ34: hey, why is it again why ppl shgouldnt use bosch plugs witht he 3.4?
AaronZ34: i forgot.
SappySE1O7: platinums because half the plugs first from the center out and the other half out to center
SappySE1O7: other than that, bosch just don't last for shit
SappySE1O7: the electrode eats itself
SappySE1O7: your gap starts getting larger and larger

timg wrote: If you used Bosch platinum plus 4 plugs, the misfire will go away if you swap them for Rapidfires.

TimG owns the highest WHP 3.4 that we know of, and knows a lot about turbocharging, ownign a badass turbo S2000, and his 263whp turbo MC.

whitemonteZZZ wrote: Dump the Bosch plugs for some stock Delcos. Bosch plugs are ****. Flashing SES indicates a misfire. Have you changed plug wires? I've heard mixed opinions about the Accel coils. What you could so is scan to see what cylinder is misfiring, swap plug wires (eg. if cyl 3 misfires, take a wire from another cyl and swap the two, and see if the misfire goes to the other cylinder) to test wires. But get rid of the bosch plugs to start and throw delcos in (rapidfires are a very good plug from Delco)>>

Heza wrote: the whole platinum plug conspiracy is bull****. i just pulled my Delco platinums that were factory in my car. thats whats called for in my service manual. 72k miles later. Bosch platinums suck...that is a culprit!

mstrjon42 wrote: don't use the +4's. they're crapola. get AC delco plugs.

or don't take my advice. but, you'll be sorry. everyone i've talked to has had problems with Bosch plugs sooner or later, but I use AC in any car I tune up (well, they're all GM cars) and never had a plug problem.

So assfuck, is this good enough?

Aaron wrote:Ok dumbfuck, is ben (www.60degreev6.com) a good enough source for you considering he knows more about the 3.4 DOHC than anybody we know of?

You can see why he's questioning you right? I mean, you are the official dumbfuck of the forum.

Anything you say is automatically suspect.

Village idiots are laughed at, not listened to.

I've always read that using platinum plugs on a DIS system is a bad idea, because the waste spark tends to kill the electrode... I've always used Delco in my Q4 without any problems.

Standard wrote:I've always read that using platinum plugs on a DIS system is a bad idea, because the waste spark tends to kill the electrode... I've always used Delco in my Q4 without any problems.

I've heard that as well.

I wonder if it applies to a 1994-1995 3.4, which uses SFI, but still goes to batch fire above 4000rpm?