spluttering engine

[JL1978]

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:

[asp]

what was ur boost b4 u turnd it down?

[JL1978]

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....

[rx7veilside]

21psi.....kaboom..hope it is running apexi/injectors/pump/map etc mine is about 15psi with everything uprated

[asp]

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

[JL1978]

damage 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

[iaint]

Does sound like fuel cut by the ECU -  what ECU do you have in there and how are you controlling boost?

[JL1978]

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

[rx7veilside]

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

[nikp]

21psi is a touch over 1.4 bar!!