Jump to content
Please check your junk folder for registration emails ×
  • Current Donation Goals

    • Raised $0.00

Pls help: limp mode, black smoke, bad fuel economy


swamp

Recommended Posts

Hi guys ive let my MY94 GF8 sit for 6 months while I travelled the country. I returned to my car idling very poorly - jumping from 2.5k to 1k rpm which was fixed by cleaning out iacv and tb. Cleaned out MAF. All done with brake cleaner which the internet has said is safe, not as $$ as purpose built products but better than using harsher products like carb cleaner. 

 

Then since first drive I've been in limp mode; put it down to a boost leak - found a gaping hole in turbo compressor-ic pipe which I've replaced. My car has blown alot of smoke since I've cleaned out TB/iacv, but when driving on limp mode this has been black smoke. Plus $55 gas at like $2.35/l only got me 80km lol so there's a fueling issue there. 

 

I've also made a big mistake of clearing codes by disconnecting negative terminal of battery thinking this was part of cleaning iacv but I've gone and wiped all codes by accident :( 

 

Can anyone recommend a solution please. I'm thinking of 1. Inspecting spark plugs and cleaning (they haven't been done in my 20000km of ownership) 2. Running some injector cleaner in the fuel tank and 3. Testing the MAF with a multimeter. 

 

 

Link to comment
Share on other sites

  • Admin

Since you’ve mentioned in the other thread that your idle still isn’t completely stable, might be worth seeing if there is another leak somewhere, check all vac lines too. 

Then O2 sensor is probably the next thing on the list to check with the rubbish economy. 

 

Won’t there always be a code active if it's in limp mode? Pretty sure resetting the ECU dismisses the codes and limp mode and if it comes back there should be an accompanying code as well.

 

Spark plugs are relatively cheap so worth doing just so you have a record of how old they are. If they’re coppers then they’ll definitely be due for replacement anyway. If super tight on funds you could clean them up and set the correct gap but depends on how worn they look when removing.

  • Like 2
Link to comment
Share on other sites

  • Admin

If it's smoking like crazy I would say unlikely to be AFM or O2 sensor; if it's doing it under vacuum then it's probably not an air leak as this would make you go lean instead. I'm going to take a guess on a failing or partially blocked injector massively overfuelling a cylinder. Inspect the plugs (you may as well replace them unless you know they're platinum/iridiums) and you may find just one cylinder has a totally black/fouled plug. Second guess would be something failing in the ignition; coil maybe.

  • Like 3
Link to comment
Share on other sites

Cheers guys I'm trying to do plugs now but seems a 3/8 just can't get in there to grip the plug. The car starts but dies a split second after. Once I get it going I'll be able to get codes. 

 

Edit: im trying to use a 5/8. 

Edited by swamp
See above
Link to comment
Share on other sites

 Cheers guys for your responses. Fortunately it wasn't anything expensive like a faulty injector, ignition coil or sensor. I had spent the most hours and money trying to fix my boost leak (coming from the turbo compressor side to intercooler). Car currently drives fine and builds boost.

 

Battery read at 11v so that got a charge, maf sensor was working fine but I'm yet to go over that again with the car running. Fuel was pumping through fine. Put it down to spark.

 

I had already pulled my plugs last night. I used a standard deep 16mm socket as I found 5/8 spark plug socket did not grab at all. 

 

Installed new NGK platinum plugs today, old ones were terrible and even though they were platinum, fouled, electrodes were worn and smelt like fuel. Gapped the new ones too to .06mm which was recommended online. 

 

Replaced the fuel filter too which had rust. Probably hadn't been changed in years. Chucked in some fuel injector cleaner - I went with Rislone as it was cheapish and the marketing did put alot of emphasis on clearing injectors. 

 

It started up and runs fine!! Turns out it was the plugs. I would think that they were just worn out, but cleaning out the throttle body/maf/iacv with brake kleen probably clogged them up so bad it killed them. Would advise those doing intake cleans that they do it with old one cheap plugs. :)

 

Link to comment
Share on other sites

Problem solved, but I was just wondering as I had a boost leak yesterday due to doing a lazy job of fixing the pipe, and blew a bit of black smoke, should I need to clean my spark plugs? 

 

If so this time I am wearing gloves. :(

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Similar Content

  • Recent Status Updates

    • MrSg9Sti04

      Afternoon team,
      im new to the group first time posting. Im hoping some body can help me get my launch control all dialled in on my link g4x. Ive had the computer and car all tuned from chris at prestige awesome knowlegable guy super happy with the results but now im wanting to get my launch/anti lag all dialled in. Ive been reading multiple different forums etc all with different conflicking information which has made me nervious with what do i listen to this or that if you get what i mean. Now ive started to make myself familiar with my PClink software etc the past few weeks and im eager to learn how to do minor setups or tweaks etc so im not relieing on my tuner so much and obviously saving myself abit hurt in the back pocket. 
      Now back to the question at hand.... Im wondering if theres and one who could please share there knowledge and wisdom with setting all my values, timing, fuel etc when i have launch control armed and engaged, or even a launch tune file they can possibly send me to load onto my tune. Ive figured out the setup of my digital inputs turning launch control on etc and its obvisously on its pre set factory settings. It engages but doesnt sound the greatest or as angry as it should i feel. Hence reaching out to you good buggers. 
       
      Cheers in advance for any info and help yous maybe able to give me.
       
      Cheers Shaun
      · 0 replies
    • Joker  »  gotasuby

      updated your DP's too : hope that's ok!
      · 0 replies
    • Joker  »  SAS

      Updated your DP's to reflect your business page  
      · 0 replies
    • Joker  »  Nachoooo

      Updated your Avatar : couldnt help myself  cheers!
      · 0 replies
  • Recently Browsing   0 members

    • No registered users viewing this page.
  • Forum Statistics

    40.9k
    Total Topics
    573.5k
    Total Posts


×
×
  • Create New...