Backfiring, Through carb and exhaust
Turbo Mini Forums

Yea i have removed the intercooler so its running NA at the moment, as this mean im getting alot less backfiring through the carb.

Ill have another play with thefueling and timing tomorrow.

best bet is to jsut get it rolling roaded propely by someone and get it set up spot on. it wil never run perfect unless its set up on a rolling road

Yea i do plan to get it rolling roaded, but i dont really get any spare time at the moment to go over and get it set up...

Iv been told BD Engineering in Sittingbourne are good, but that the only local on i know of now lol, do you know of any other local rollers?

I ritchened the mixture up a bit before i left work this afternoon and it didnt seem to backfire all the way home, but ill have to see what its like when i fit my intercooler back on as i was getting the carb backfiring alot more with the turbo plumbed in...

But i did find that on the way home the temp nearly hit the red and it didnt get that high before, it used to sit at about 3/4 on the motorway.

Edited by tomf on 8th Jul, 2010.

mmm sounds like it does jsut need a good set up. your best of getting it trucked or trailed up to ray in colchester. he is good at setting up turbo minis with megajolt

Has he got a rolling road?

Ok well scrap the idea of the ritchening stopping the backfiring, i just drove to the gym and it was fine all the way, there buy on the way back it backfired through the carb about 6 times... Was a little odd, if i was in 3rd or 4th once i got to about 2000rpm the engine would glitch and be as if its not runnig, then backfire through the carb then would be fine...

Lean!!! stop driving it!

Yea but whats causing it to go lean? As it appears to be fine sometime but not others. And the carb fueing is defonately ritch now.

A trip to the rollers will help you find out. As others have said, if you keep driving it, you will end up melting something...

Possibly but it has been running like this for 3000 miles now and nothing has melted... and im doing atleast 40 miles a day.

Im not running with the turbo connected at the moment, but yes i agree a trip to the rollers in needed, but personally i dont feel this is down to a carb tuning issue or timing as i have tried so many different settings now and exan running NA it wont run right.

im am unsure how lean it has to be to missfire, but i could pull about 17.5afr on cruse when i was fettling my needle, yours must be spiking leaner than that to miss

Yes i moved to the darkside

Instagram @jdm_brett

This is what i cant understand, i drover a 20+ miles journey with not a single backfire, thats town, country and motorway driving.

I then drove to the about 5 miles to the gym, country and town driving, without a carb backfire.

I then drove home from the gym same route as i took to get there and it was backfiring through the carb loads...

Just doent make sense really, i would idealy like to try and find my problem out before i take it on the rollers as personally i feel this isnt down to setting up of the carb or timing, so i think that if i take it to the rollers it will cost me a fair wedge then it might just me a waste of my time and money for them to just say oh this is wrong buy we cant do anything about it right now...

bi metallic strip in the float bowl?

Yes i moved to the darkside

Instagram @jdm_brett

Im not to sure what that is, but iv had this problem with two carbs now, one being a fully re-built carb.

the jet is held by a strip that bends depending on fuel temp this affecs how much fuel the engine gets there are threads about its affects if you search, some people found they need to remove it and replace with steel to stop the fuel changging with temurature

Yes i moved to the darkside

Instagram @jdm_brett

just seen the pics (for the first time)

i would do this i had to do it to my n/a remove and block yhe part throttle leanoff

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Yes i moved to the darkside

Instagram @jdm_brett

instead of going to the gym,
take it to a rolling road like we have all said.....OR
chances areit will end in tears somewhere long the line....

t and m electircal. ask for ray. book in with him

Thanks ill try blockin the part lean off pipe and see if that helpd.

Well if the rolling roads were open in the evenings i would do that, but unfortunately they arent.

Cheers mate ill see if i can find a number.

If it's intermittent I'd say it could be an ignition fault, causing a misfire. I had this last year when running a coil & dizzy, it only did it now & again. But caused a big mifire.

WWW.TURBO-MINI.COM

I guess it could be an ignition problem iv got a spare crank sensor, coil pack, so ill try them and see if they help.

well lucky for you some are.............
www.atspeedracing.co.uk,

il be honest and i didnt really like TM's....

www.atspeedracing.co.uk,

wooops ment to copy and paste that into the web browser not reply ha

lol,
you busy today?
im gonna be tuboing the blue metro.....

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will