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Mazda Rotary Club

General => General Technical => Topic started by: JL1978 on May 29, 2005, 04:21:24 PM

Title: spluttering engine
Post by: JL1978 on May 29, 2005, 04:21:24 PM
My rx7 3rd gen has just started playing up , when im doing about 5000rpm she starts spluttering as if its misfiring or has fuel starvation   It starts first time and has a very good tick over and it runs smooth up until 5000rpm..  I was told to double up the earth wires because it’s a common fault but I already have a earth kit on the car so I didn’t think it was that … I noticed that the second turbo kicks in at 5000 so maybe that could be the problem, Just out of chance I turned the boost all the way down and the problem has gone…..  Has anyone had a similar problem and was it a problem with the turbos?????    Im thinking plugs, earth or turbos issue…..

Please help jl1978
:confused:
Title: spluttering engine
Post by: asp on May 29, 2005, 06:16:16 PM
what was ur boost b4 u turnd it down?
Title: spluttering engine
Post by: JL1978 on May 30, 2005, 12:30:51 PM
When i bought the car it was set at 21psi , its now set at 7psi which seems to have stopped the problem.... could this just be a over boosting problem? And i dont mean to sound thick but can i damage the turbos\' running it on standard boost?

     I was told last nite to try and set it at 14psi to see if she runs ok at that setting....
Title: spluttering engine
Post by: rx7veilside on May 30, 2005, 01:45:43 PM
21psi.....kaboom..hope it is running apexi/injectors/pump/map etc mine is about 15psi with everything uprated
Title: spluttering engine
Post by: asp on May 30, 2005, 08:46:57 PM
damage the turbos,,,,ur lucky u didnt blow ur engine up.
if u aint got the mods that rx7veilside said,u shouldnt b boostin 21psi
Title: spluttering engine
Post by: JL1978 on May 31, 2005, 06:23:49 PM
Quotedamage the turbos,,,,ur lucky u didnt blow ur engine up.

     I didnt set the boost on the car , thats how it was set when i bought it ....  the problem only started last week , Ive been out in it all weekend and she seems fine now
Title: spluttering engine
Post by: iaint on May 31, 2005, 07:04:18 PM
Does sound like fuel cut by the ECU -  what ECU do you have in there and how are you controlling boost?
Title: spluttering engine
Post by: JL1978 on June 01, 2005, 03:56:39 AM
the ecu is a knights sport , i have a apexi boost gauge but to change the boost its a little block in the engine with a bolt in it  , I have been told that these can cause spikes to the engine , so im going to invest in a apexi digital boost controller
Title: spluttering engine
Post by: rx7veilside on June 01, 2005, 05:43:29 AM
sound like u have the rather crude bleed valve method..i wld be very wary of running 21psi without a fully uprated pump/injectors/regulator/map/apexi and cnfm mapped for optimax etc 21psi is about 1.3-1.4 bar ithink very high
Title: spluttering engine
Post by: nikp on June 01, 2005, 09:59:15 AM
21psi is a touch over 1.4 bar!! :eek:
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