turbo/boost problems

Johnerz · October 22, 2007, 12:07:54 PM

hope someone can help.....
i posted previously about my car being spluttery, but it seemed to clear up as i was driving the car daily and never had an issue until today (car was not driven at all yesterday)...

started the car up and was leaving the street, got on to the main road and went to accelerate and the pedal seemed heavier and the car chugged and spluttered and the exhaust kept popping as i tried to accelerate, almost like it was choked/blocked. i looked at my boost controller and it read -51, but as i accelerated it went up to 0.00 and wouldnt go past, there is no dump valve sound and none of the usual induction type sounds. the only noise from the turbo was a load whirring sound.

could this just be a loose pipe somewhere or are the turbos shafted?

any help appreciated, cheers!

Jono FD3 · October 22, 2007, 12:59:07 PM

Have you got a kat on the car???

If you have, this might have collapsed resulting in megga backpressure which will stop the turbos from spooling!!
Have you got a boost gauge?? if so, does it waver (jump up and down) at idle?? if so your tips are shot!!

Jono

leon · October 22, 2007, 01:01:03 PM

That sounds like the car is in limp mode, if your having problems with the acell, especialy if it starts banging constantly when you try bring it onto boost. does it pull okay if you try to acelerate lightly?

Johnerz · October 22, 2007, 05:16:54 PM

Quote from: Jono FD3Have you got a kat on the car???

If you have, this might have collapsed resulting in megga backpressure which will stop the turbos from spooling!!
Have you got a boost gauge?? if so, does it waver (jump up and down) at idle?? if so your tips are shot!!

Jono

yes the cat is still on it, what could make it collapse? ill have to look underneath and see if i can spot anything, but it really does deel like there is mega back pressure. there is no boost gauge atm it was \'broken in transit\' and i havent had the chance to get a replacement

cheers for the advice mate

Johnerz · October 22, 2007, 05:21:27 PM

Quote from: leonThat sounds like the car is in limp mode, if your having problems with the acell, especialy if it starts banging constantly when you try bring it onto boost. does it pull okay if you try to acelerate lightly?

it is smooth right up until the boost controller reads from -41 up to zero, thats when the engine starts spluttering and if i keep the throttle down it starts backfiring and popping like a machine gun until i back off.

it revs ok in neutral, i revved it to about 6000 and the dump valve was working, if a little quiet, but then i heard that whirring noise again

RemarkLima · October 22, 2007, 05:38:15 PM

Sounds like the turbos are boosting and it\'s a loose hose, so all the air is escaping but the ECU is throwing in more fuel hence the popping and banging.

Check all your intercooler hoses and such like first.

GaseJo · October 22, 2007, 06:25:36 PM

I agree with Remarklima i had the same problem. It turned out to be a loose connection on the i/c piping

Johnerz · October 23, 2007, 01:33:25 PM

I just checked all air filter hoses, took the filters off and reconnected them. i took the pipes off the intercooler and there dosent appear to be any cracks, and none of the pipes were loose.

just find it strange that when the boost controller read 0.00 the car just stutters, pops and gives it the kangaroo petrol routine.

any other suggestions? as i live in NI there is only 1 mazda dealer that says they will service it, and there arent that many rx7s around here.

Jono FD3 · October 23, 2007, 03:49:55 PM

are you running a power FC???
if you are, it could be something daft like the fuel kut limit is too low???
Did the problem just sudenly arrise or have you done any mods to the car between the car running properly & now??

Jono

Johnerz · October 23, 2007, 04:02:58 PM

the ecu is a denso N3F1 18 881A which im assuming is factory standard?

it first happened after i left my 1st mot appointment. it drove ok on a few other test drives, then happened on the way to its 2nd mot. it seemed to clear up after the engine was turned off as i was very early.

once the car was road legal there was no problems and it was a daily driver until this weekend. it was fine on saturday, then wasnt driven sunday, then been like this ever since. im handy with a spanner, etc but if it is a turbo problem i dont fancy doing that work.

cheers

ianelvar · October 23, 2007, 05:32:05 PM

Sounds like mine when it went into limp mode. Pull the ECU error codes (howto in the tech stickies section). There are a few faults that will cause it to throw a paddy and behave like you\'re describing. Do a reset - disconnect battery and push brake pedal down, then reconnect battery - and then see what codes you can get. Mine was going nuts because the fuel pump speed relay was missing.

Johnerz · October 23, 2007, 07:40:00 PM

cheers mate ill have a read and try that.

I have it booked in for a diagnostic at the local (dare I say it) mazda dealer next month. I went in and asked plenty of questions, took one of the technicians out in it for some first impressions and had a good chat before booking it. They are helpful, seem rex friendly and said that getting parts will be no problem, taking around 3-5 days from Japan.

so fingers crossed

Johnerz · October 31, 2007, 12:43:32 PM

sorry to bring up an old post but just wanted some further info/advice.

the issue is now seems to be intermittent. I use the car daily and have been very careful driving on vacuum, but today it started up, boosted fine and the dump valve sounded spot on. i took it easy and when accelerating i do hear some hissing, but it really sounds like air leaking thru the dump valve under medium acceleration. after a while, the boost controller started reading 0.00 while under boost and the dump valve stopped working, yet i was still able to get boost. now its back to the original problem of bad stuttering and popping when coming onto boost.

Someone mentioned a pressure sensor could be damaged, but to me it sounds more like cracked/loose pipe somewhere. am hoping its the case so i dont have to take it into the mazda dealer for them to do an engine diagnostic.

can anyone give any further advice to that which i have already received?

andysmee · October 31, 2007, 01:09:40 PM

that sounds like the pipe has popped off the map sensor, you get boost, but no reading on the boost gauge.

Apologies if you\'ve already checked this

Johnerz · October 31, 2007, 01:20:07 PM

no need for apologies mate, i appreciate the help!

ill add that to my list for things to check, but other than the boost, sometimes when accelerating i will hear air hissing, then if i back off i can hear the turbines whirring, as if they are looking for the air?

really does sound like a leak but the more i can check, the more ill be sure.

turbo/boost problems

GaseJo

andysmee