high load misfire

[Jazz9]

Hello

I've just been fixing up a galant and it goes quite well now.

I can boost in 1-4 gears fine ( 16psi ) but in 5th at 4500rpm it starts to breakdown. I run nkg bpr6es plugs and 10mm leads and a 8mm gap. Its not fuel or speedcut.

Should I be running bpr7es and a smaller gap?

On lower boost its find 12 psi. Its a tdo5 20g 560cc inj, chip, 055 maf, 3".

Glen

 

[Gianni]

I'm new to tuning so been working stuff out as I go. I'm running 17psi on a stock tune. In low gears it's fine but when u get to 3rd onwards and over 5k it cuts and splutters. I've put it down as fuel cut after a bit of research. And then was told to expect fuel cut on higher boost untuned. I'm also running a 20g with 8mm leads

I didnt understand what you meant by breakdown but above is what first came to mind. But since you don't think it's fuel cut I might also think a boost leak off a vacc line or loose cooler clamp. That can cause it to kinda splitter and struggle with power and rpms too

 

[4piknup]

Just close gap a bit more and try again. Try at .75 you will see if it worse or better before you buy new plugs. Are you sure it not running out of fuel?

 

[to4garret]

Hello

I've just been fixing up a galant and it goes quite well now.

I can boost in 1-4 gears fine ( 16psi ) but in 5th at 4500rpm it starts to breakdown. I run nkg bpr6es plugs and 10mm leads and a 8mm gap. Its not fuel or speedcut.

Should I be running bpr7es and a smaller gap?

On lower boost its find 12 psi. Its a tdo5 20g 560cc inj, chip, 055 maf, 3".

Glen

I like GAP, but 8mm is a HUGE gap for spark plugs!

You might find the BPR6ES's are a bit hot for the VR4, stock is BPR7ES.

 

[Jazz9]

lol .8

its listed as bpr6es as stock for nkg?? and then they say 1.1mm is recommended.....

im confussed !!

Glen

 

[Jazz9]

im going to check for boost leaks.

 

[bazeng]

The NGK book is incorrect.

They list NGK BPE6ES-11 (1,1mm)

You will notice under the bonnet of a VR4, it will state .8mm gap somewhere (I think JSPEC had them).

Anyway, start at .8mm and keep dropping the gap until the miss goes.
.6mm is what most guys run. The larger the gap the more efficient the burn.

 

[DOUGMO]

yeah, .65mm on 7s imo

 

[Entaran]

Mine's running BPR6's at 0.75mm gap. Not that I overly trust my mechanic so I gapped my own plugs before I gave them to him and told him not to touch them.

The 1.1mm gap is for the non turbo engines.

 

[4piknup]

+1 to baz and dougmo
There is a rule of thumb, I think it is 0.1mm closed for every 1lb of boost.?
Sorry I think it's 1thou for every 1lb of boost.
So 1 thou is 0.0254, x 17lb boost is 0.4318. Subtract that from 1.1mm gap is 0.67mm

Just take it down .5 at a time and see if it improves

 

[LANCEREVO]

thats wat mine started doing its the coilpacks breaking down

 

[Jazz9]

hmm, can you get a coilpack off a sonata or something a bit newer? The 20+ year old coilpacks are getting a but old.

I'll go and grab some bpr7es and gap .65 FTW then some more boost.

Glen

 

[Gianni]

The Hyundai coil packs are same as galant. With the mounts and loom....but I took off the loom and attached my Evo loom to it. Then bolted the Hyundai coils to my mount plate. .

 

[blackvr]

Just lately, I have had a real run of faulty/worn coil packs on customer VR4s. My electrical components supplier has found new Genuine Hyundai coil packs for around $115. I know he gets them from Melbourne some where. For that price, I dont stuff around any more !! Also, I've just started seeing a few VR4's with a considerable voltage drop to the coil packs. "Somewhere" in the loom, I have lost 2, and up to 3 volts. By installing a relay to bring battery voltage in( much like the fuel pump voltage fix), I now get a decent 14+V to the coils . That now means a miss fire free power levels of 220kw plus on higher 20psi boost levels. Dont mess with "good" seconhand coil packs... they are quite often the reason why you have to drop the spark plug gaps to micro levels...

 

[Jazz9]

Well at that price. Hook me up, pm me your bank details and postage costs. I'll let everyone know how I go with it.

 

[blackvr]

PM sent..

 

[blackvr]

Well at that price. Hook me up, pm me your bank details and postage costs. I'll let everyone know how I go with it.

Glen, could you PM me posting details etc.. Mike

 

[Jazz9]

Hello Blackvr,

I've sent my details to your pm box a while ago now. Please pm me your phone number so I can call you.

Glen

 

[blackvr]

Hello Blackvr,

I've sent my details to your pm box a while ago now. Please pm me your phone number so I can call you.

Glen

Glen, I am sorry... the PM hasnt lobbed into my box. I have received funds and was waiting for posting details.. Ring me on 0417 083 682 , or PM details.. Cheers Mike

 

[milkandoj]

Just lately, I have had a real run of faulty/worn coil packs on customer VR4s. My electrical components supplier has found new Genuine Hyundai coil packs for around $115. I know he gets them from Melbourne some where. For that price, I dont stuff around any more !! Also, I've just started seeing a few VR4's with a considerable voltage drop to the coil packs. "Somewhere" in the loom, I have lost 2, and up to 3 volts. By installing a relay to bring battery voltage in( much like the fuel pump voltage fix), I now get a decent 14+V to the coils . That now means a miss fire free power levels of 220kw plus on higher 20psi boost levels. Dont mess with "good" seconhand coil packs... they are quite often the reason why you have to drop the spark plug gaps to micro levels...

How do you test the voltage getting to the coil and also the output or how worn they as i have a spare set id like to compare them to the set on my car, and run whichever ones are in best condition. Do they wear out over time or are they either good or not.