Just took my car for a spin today and had a slight problem...
I was badly cut up by a rep in a rover 75:reallymad So in order to demonstrate that he really didn\'t want a rover 75 and really wanted an RX7 I thought I would show him a clean pair of heals... Not in a bad or reckless way of course!:p
Having a straight stretch of road ahead I drop it down to 2nd to get the revs up and floored the accelarator expecting everything to pick up... Now I wasn\'t looking at the boost gauge at the time so this is where the symptoms get a bit shaky.
The power began to pick up and then I lost a fair amount of power in fact almost all of it. I hadn\'t reached the rev limiter and the engine was still running (I checked as the loss in power was that dramatic). I aborted my run and left the rover to disappear into the distance :bandit however everything seemed to return to normal after that.
Since having the car (about a month now) I\'ve been taking it easy and getting used to the power delivery slowly but i\'ve begun to notice that when holding it in gear through the rev band the power delivery is not as smooth as I would have expected. with a least one did in power at around 5K revs. The problem today seemed to be a further development of this?:confused:
I\'m running the car on Shell Optimax or BP Ultima and had assumed that the hessitant accelaration might be due to the lower octane rating compared with Japan.
Questions...
Does it sound as though the engine needs mapping for the lower octane fuels over here?
The car has clearly been owned by an enthusiast - so how do I check if it has a 16bit ECU?
As I changed down could the dump valve have dumped all my turbo pressure to cause this loss in power?
Or is it as simple as a blocked hose somewhere? And if so where?
What boost are you running mate?
Sounds like you might be loosing power as the second turbo kicks in, if it doesn\'t feel to smooth normally perhaps this time the solanoid didn\'t open at all and so you didn\'t get the second turbo kicking in?
Any one else?
Dave
There could be a host of possibilities. I think it would be easier to start with what mods you have on the car, and does this only happen intermittently, all the time what does the boost gauge show when it happens etc.
rgds
I have something similar to this. The second turbo operation is sometimes very hesitant, and the car just won\'t pull cleanly. I suspect it\'s down to the rubber and plastic hoses, as these are apparently a weka link in the fd. The second turbo won\'t kick in if the first is not pushing out 8psi (correct me if I\'m wrong people!), and apparently what can happen sometimes is the pressure can suck the induction ducting to the first turbo together, starving it of air - and therefore the second turbo won\'t operate properly.
I suspect this to be the case with mine, as it worked perfectly the other day when it was cold, and the engine had just got up to temperature - the fact that the engine bay hadn\'t got hugely hot meant that the pipes were not as pliable as when it\'s warmed the engine bay up a lot. I\'m going to replace some of the pipes with harder silicone pipes in the next couple of weeks and see if it solves the problem.
Also vacuum leaks can occur from pipes either from loose connections, or cracks in old and tired rubber hoses. Might be worth checking those too.
That\'s my two pence worth!
The dip in power around %k rpm is normal - it\'s the 2nd turbo coming online. After that point you should feel a huge kick as it gets it\'s shit on.
Iain
Thanks for the response. In reply to the mods question...
The car was imported recently. I did ask for an unmodified car but these seemed too hard to get. The importer beleived it to be failry standard but had a few surprises when it turned up.
It clearly has a dump valve and boost gauge (it\'s an apexi guage so guess ann apexi dump valve?). It has a bigger exhaust (3" i think) but still has a cat. Now as far as I know that all in terms of engine. It also has adjustable suspension and an aftermarket brace between the macpherson struts across the engine bay. It also has a turbo timer.
I was considering getting it on a rolling road as perhaps this is the best way to find out if it\'s been ported??? but under the bonnet everything looks like the books!
The rolling road plan would be to get it de-catted and a new 16bit ECU (if it needs one!) and then get it mapped with the mods.
Boost is up around the 1Bar mark - just over at full wack!
Thats lots of boost to be honest and not standard at all.
Standard fuel cut is at about 0.8bar so this may well be your problem.
For 1bar + you would be hard on ECU, injectors, turbos so you would want a few uprated things if it is over 1bar.
Lee
You may have noticed that I\'m fairly new to modified turbo cars and am on a steep learning curve. :p
I never had tricky boost gauges and dump valves on my rover 220 coupe - but then it was standard and I just took it to the main dealer!:D
hmm. Sounds like a trip to a specialist is in order to find out exactly what it has got then!
Definitely sounds like fuel cut, although getting fuel cut with just a back box does not add up. If your getting around 1bar under acceleration there is more done to you car than just a back box or a problem. Need to take it to a garage to get checked.
rgds
What year is your FD? Mine is one of the first 16bit factory ECUs. I think they started with chassis FD400xxx.
The symptoms you have now are very similar to mine however mine are caused I think by not having a cat. (It was totalled when I got the car in June). I now sometimes get fuel cut at 4.5-5K rpm.
Do you definitely still have a cat ie have you actually seen it? The aftermarket exhaust will be contributing to the problem if you don\'t. My car got through its SVA then MOT with a knackered cat so yours might have too!!
Do you get correct boost above 5K rpm most of the time? If so then it is almost certainly fuel cut by the ECU. Get the exhaust back pressure checked.
As others have said, best to visit a specialist as I spent some months and a lot of cash letting local places look at the car without finding anything!!
Good luck
Angus
i get quite a big flat spot between 4 1/2 to 5 as the first turbo runs out of steam and the second one suddenly pounds into life, 1st month i had mine it was only running with 1 turbo as the boost controller was disconected. (tnx rotechnics :) )
i get a similar problem latley , i can drive the car for 10mins and the 2nd turbos allways kicking in then i can stop for an hour go back out and the second turbo doesnt work, then it can just start working again from nowhere , has only just started happening since the weather started getting colder,
anybody have any ideas,
p.s i also find that the oil cap gets ssort of presurised on and is impossible to release without a wrench of sumkind????
I\'ve also got problems with the second turbo. First one runs fine with a solid 13-14 psi, transition at around 4.5k, but the second turbos always give a solid 7-8 psi, but no more. Other than slight changes depending on the weather, it\'s always the same.
QuoteOriginally posted by JimboRX-7
I\'ve also got problems with the second turbo. First one runs fine with a solid 13-14 psi, transition at around 4.5k, but the second turbos always give a solid 7-8 psi, but no more. Other than slight changes depending on the weather, it\'s always the same.
Afaik the second turbo is only suppose to give around 6 - 7 psi, less than the first. when Rotechnics did mine the 1st turbo is only set to 7psi and second to 5psi....which seems a little low..
That is very low, unless you\'re running in a new engine perhaps ?
Standard boost pattern is approx. 10-8-10
hi ,
Im getting the same thing with my import , with the high boost then nothing , I checked my ECU and found a "knight sport FCD" connected to it.:D
still getting that now it works now it dont thing, Im hoping to get the chance to get to uk before rotorstock and get pip to work some magic
si
QuoteOriginally posted by JimboRX-7
Standard boost pattern is approx. 10-8-10
Excuse my ignorance here but what does 10-8-10 actually mean?
I assume the figures are PSI but why three?!?!
QuoteOriginally posted by peace2make
Excuse my ignorance here but what does 10-8-10 actually mean?
I assume the figures are PSI but why three?!?!
It\'s referring to the boost pattern accross the turbos.
10 PSI from 2.5k RPM - ~4k RPM
8 PSI as the 2nd turbo comes online (~4k - ~4.5k)
10 PSI from ~4.5k rpm up.
That also equates to ~ 0.8 - 0.5 - 0.8 in bar.
There is usually some trail-off on the 2nd turbo at high rpm not that you usually have time to look. Passengers help!
Iain