Jump to content
Sign in to follow this  
Brian Fahy

Spark Plug Reading

Recommended Posts

Posted (edited)

Hows it going  ive recently went to td04 setup in my boxy. Ive changed the plugs and have taken one out now and was wondering if somone could read it to see if there is anything untoward going on. 

Setup is standard injectors, mani, decat, new td04L internally gated with Hks adjustable actuator full 2 1/2” straight through exhaust, bosch 044 external pump, cold air relocate, front mount intercooler,blitz access pnp ecu. Running only .5bar with small creep to just under .6 > Spark plugs are ngk bkr7e gapped to .8mm

My concern is the ground strap being white, is this indicative of an ignition timing issue or the wrong heat range plug ? 

Any info appreciated, thanks 

ECD19BB0-4C24-4704-876A-89E7E8BA557B.jpeg

6E2BF2EC-BA66-4841-8FAF-FB5157A81228.jpeg

Edited by Brian Fahy

Share this post


Link to post
Share on other sites
Posted (edited)

Quite a bit of cement boil and the shroud is to black. What's your fuel pressure set to and I'd get the injectors cleaned. What boost pressure are you running. Which cylinder is the plug out of and are all the plug shroud this black. 

Edited by Sam44

Share this post


Link to post
Share on other sites
Posted (edited)
On 6/22/2020 at 12:58 PM, Sam44 said:

Quite a bit of cement boil and the shroud is to black. What's your fuel pressure set to and I'd get the injectors cleaned. What boost pressure are you running. Which cylinder is the plug out of and are all the plug shroud this black. 

Well lad she has the standard fuel pressure reg so i would imagine ~2.5bar base pressure. The injectors have been refurbed and flow tested, all within 5%. I am currently only running just under .6bar I was under the inpression that the outer shroud is black due to running rich which is safe to say as i am using the blitz access ecu which tends to run richer than stock and also the 255lph 044. All spark plugs are almost identical to one another. Had hybrid ct9 setup not too long along and everything was spot on at .8bar. Ct9 setup was run on standard ecu and got the blitz to run the td04 for i was hoping.8bar. I belivee that the blitz may have somthing to do with it as it has abit more aggressive timing/fueling etc so my belief is that the base ignition timing from the dizzy is abit out and from this the more ‘aggressive’ timing is causing to go out of its safe operating or ideal range. Currently i am unable to set/check the base ignition timing again due part of the crank pulley having chipped off around the mark used to time it up with cover. I have a 4efe one on the way for the time being. It is not being driven so I was just trying to pick some brains to see if anyone could help as you can imagine I do not want to cause any negligent damage. Thanks for your reply. 

Edited by Brian Fahy

Share this post


Link to post
Share on other sites

I would suggest fitting a wideband o2 sensor and gauge to read the AFR's as well as timing check (when you can).

Also be aware that the 4efe crank pulley isn't a harmonic balancer type like the 4efte one is. Some have expressed concerns about using the non harmonic type.

A lean condition and too advanced spark is a recipe for melted pistons. You have done the right thing to be cautious.

I'm certainly not an expert in reading spark plugs but after doing some internet research, soot on the outer part can be rich at idle, might not be rich at full throttle though.

Share this post


Link to post
Share on other sites
Posted (edited)

The 4efe pully I have here is a damping\balancing (harmonic) pully can send you pictures of the unit here you can see the rubber damping layer. Not sure on all 4efe engine veriants and years mines an ep 91 cd UK starlet I'd be very very surprised if a manufacturer did not balance anything on the crank shaft.

I'd say  The mixture isn't lean I'd say it's not atomising properly either injector fouling or low fuel pressure, there's alot of crust (cement boil) on the center earth electrode this happens when the fuels boils instead of being atomised both the black outer and white inner also contribute to this.

When I tested my fuel pressure it was 30psi at idle throttle closed and 32psi throttle open. I got better fueling results showing on my wide band, egt and plugs from 32psi idle upto 40psi open throttle the power difference was also very noticable. 36psi us a sweet spot I've setup a GT turbo recently on a near standard ct9 standard high boost using an fse fpr throttle open is very noticable. The GT also had 30psi and 32psi fuel pressure on standard fpr. Just to add near all denso top feed injectors record 30psi on the data sheets I've seen so this confirms the physical results I've seen. 

In this cylinder you are running the wrong heat range plug. I'd drop to a 6. It's normally around 1bar of boost a heat range 7 is required. Compression ratio and fuel mix dependant. the colour of the center electrode white insulation but first I'd try and up the fuel pressure alittle and see if it cleans up the plug. 

If you can get me better high resolution up close pictures I can help alittle better. 

Always a great idea to check ignition timing. 

Edited by Sam44

Share this post


Link to post
Share on other sites
Posted (edited)
2 hours ago, Sam44 said:

The 4efe pully I have here is a damping\balancing (harmonic) pully can send you pictures of the unit here you can see the rubber damping layer. Not sure on all 4efe engine veriants and years mines an ep 91 cd UK starlet I'd be very very surprised if a manufacturer did not balance anything on the crank shaft.

Yeah, I only went by what I'd read on the forums. The further I look there appears to be a rubber layer on some shown examples. I'll check mine when I change the cambelt. There are differences in weight though between fe and fte which some are worried about but then some say that they've run it with the fe pulley and its been fine!? 

Edited by Claymore

Share this post


Link to post
Share on other sites
Posted (edited)
On 6/28/2020 at 7:54 PM, Claymore said:

Yeah, I only went by what I'd read on the forums. The further I look there appears to be a rubber layer on some shown examples. I'll check mine when I change the cambelt. There are differences in weight though between fe and fte which some are worried about but then some say that they've run it with the fe pulley and its been fine!? 

That's what I'm finding also. Same with the base fuel pressure. The 4efte pullys are alot stronger, hit of boost (power surge) the weight will also act as a second flywheel (low compression). I'm finding Toyota gtt site is alot more accurate, and helpful. 

Something I've noticed on this site is posts around and before 2008 to 20013 seem to be reliable. 

Edited by Sam44

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Sign in to follow this  

×
×
  • Create New...