loss of power and spluttering under accelleration

[Juz]

my rex is poorly

this morning everything was running fine in the dry weather, then this afternoon i got in the car only 1hr after it had been running great (and boosting absolutely brilliantly!) but now in the pi$$ing rain, and i found that in any gear as soon as i accellerate by anything more than a very very light amount it just splutters, the exhaust makes lots of loud farting (louder than the pops it makes when it\'s running well when driving hard and changing down a gear) and the power just drops completely until i back off. this happens through all the gears and in neutral. all my guages were showing fine i.e. coolant and oil pressure (car is stock twin turbo with stock ecu) and she sounds absolutely perfect at idle and driving until anything more than a light touch of the accellerator is applied, so i managed to drive the 5 miles home having to wait for massive gaps at roundabouts lol but now i\'m scared to drive it until i can fix this in case it makes a problem worse...

i already did a bit of searching for similiar problems on here and as a result have checked the earth and it\'s not loose, i tried resetting the ecu by leaving the battery disconnected for 30 mins then reconnecting with the brake applied. i also checked the "egi" fuse and other fuses next to the battery and they all look ok.

please please help, i need suggestions as to what to try so i can hopefully have it running good again this weekend! i can\'t believe this, it\'s the first actual proper problem i\'ve ever had with 2 rx7\'s after all this time and i\'m dreading everyone going to tell me it will need rebuilding...

[Juz]

also after reading up some more on this symptom i thought this info might be useful in trying to diagnose it...

there are no problems starting the engine, it fires first time every time whether hot or allowed to cool down first.

there\'s no noticable smoke from the exhaust.

i have tried letting it idle for a while and it is steady all the time, doesn\'t go 30 secs smooth, 30 secs rough or anything like that.

[James B]

Sounds like lack of fuel to me ......... but I am not technical it is just I had a similar sounding fault ....... secondary injectors not kicking in although it sounds like you are not getting very high in the rev range before this happens ...... anyway an idea.

James

[Juz]

in my original post i put that it was getting to 2.5k revs before this happens, but i edited it to clarify that after a second look i realised the problem doesn\'t seem related to the revs, rather just that if i accelerate as gently as possible it will rev all the way round but if at any point i accelerate normally or hard then it completely loses power and the revs drop.

i too am not very technical but the fueling sounds like it could be worth checking out - is it a big job for someone inexperienced to get to the fuel injectors and check them? what sort of things should i be looking for to find out whether they are kicking in properly? thanks for the suggestion too btw much appreciated!

[RemarkLima]

Don\'t know about rotaries but I assume the basic mechanics are the same, and that symptom sounds like ignition failure, either the coil isn\'t giving enough spark, the leads are loosing too much or the plugs are fouled / on their way out.

Check the plug condition to see if they\'ve been burnt etc... Basically with more throttle / boost you need a stronger spark to bridge the gap in the high pressure, or it just will fizzle out and there\'ll be no spark.

That\'s what I\'d look at on a piston engine... And given the rain could have been something\'s gotten wet and so shorting a bit more than it should...

[D2BBA]

I had exactly the same problem when I got caught out in heavy rain the other day mate.

She seems to drive fine now, but if you find out what the problem is pleaee post it, and i\'ll do likewise!

Chris

[Juz]

I\'ve checked over the HT leads and they seem intact but I don\'t have the equipment or tools here to check the plugs. I also don\'t fancy taking on checking the injectors myself, having looked at what has to come off in order to get to them. With any other car I would happily have a go but I don\'t know where to start with this lol!

I think I\'m gonna have to try and get it in to WGT, does anybody know of any companies in the South Yorkshrie area who rent out car transporter flatback trucks? None of our cars have towbars so a trailer is out of the equation.

[Timrxmotors]

Sounds like it is in \'limp home mode\'.You can reset the ecu,as you have done,but if the fault is still present the ecu will go straight back into \'limp home mode\'.Check wires to metering oil pump,quite often damaged by the drive belts.Check wiring plugs on all sensors,and secondary injectors.

[trevtubby]

I had this on my MR2 Turbo, I know this is an RX7, but the symptoms sound very similar.

Car starting spluttering etc when the turbo tried to kick in, but I could accelerate slowly not using the turbo. I went to various places and changed the whole ignition system, airflow meter, loads of stuff.

turned out all it was, was a split intercooler silicone join, check them mate first...it cost me over a £1000 to sort out a £10 problem

[D2BBA]

I\'ve checked over the HT leads and they seem intact but I don\'t have the equipment or tools here to check the plugs. I also don\'t fancy taking on checking the injectors myself, having looked at what has to come off in order to get to them. With any other car I would happily have a go but I don\'t know where to start with this lol!

I think I\'m gonna have to try and get it in to WGT, does anybody know of any companies in the South Yorkshrie area who rent out car transporter flatback trucks? None of our cars have towbars so a trailer is out of the equation.

Try doing a search on the \'net mate.  I got a load of prices for TOTB last year.  Cant remember the site tho, so sorry!

Dont forget to post an answer (or better yet PM me!) when Pip has had a look!

Thanks
Chris

[Juz]

Dont forget to post an answer (or better yet PM me!) when Pip has had a look!

sorry for the delay, i\'ve been on holiday whilst the car was at w.g.t.!

anyways i picked her up today all fixed i didn\'t get to speak to pip himself as he was on lunch when i got there but the problem was something to do with the boost control causing the ecu to stick it in limp mode, which is why i was losing power under acceleration.

i can\'t emphasise how relieved i was because after all this time of trouble free rexing i thought i was finally gonna be hit with a rebuild, but she is still good and strong yay \\o/ that drive home across the pennines was just as much fun as the first time i ever drove one, the grin on my face must have made people going the other direction think i was barmy!

however whilst i was on holiday i met somebody with a black \'52 mercedes 300 and have fallen absolutely in love with it. i jokingly told her i would buy it off her and then she jokingly said ok then make me an offer! lol. now i need a performance car (medically, i do) but if i want to get one of these old beauties in restored condition then i won\'t be able to afford the rex as well so i\'m in a dilemna (well actually i can\'t find any 300\'s for sale that are exactly what i\'m after yet so at least i\'m not in a dilemna just yet!).

[Juz]

i guess i spoke too soon! she drove brilliantly for a hundred miles or so and then this morning the problem began again but worse, and this time it cut out and won\'t even turn over for longer than a couple of seconds now before dieing to a very poorly sounding soundtrack. back to the garage and now i\'m flippin\' stuck for a car for work

[Fats]

I had this problem on my mr2 turbo, when it was dry drove perfect, as soon as it started to rain, spluttering, misfiring and eventualy it would cut out, found my self trying to find the problem in the rain on the side of a main road!!!, had a huge ****er of the coil when i touched it! bingo! the coil had a slight crack in the housing, just my 2p, worth checking

[Mrs Copie]

I had this on my MR2 Turbo, I know this is an RX7, but the symptoms sound very similar.

Car starting spluttering etc when the turbo tried to kick in, but I could accelerate slowly not using the turbo. I went to various places and changed the whole ignition system, airflow meter, loads of stuff.

turned out all it was, was a split intercooler silicone join, check them mate first...it cost me over a £1000 to sort out a £10 problem

ooh handy to know as mine is doing the same. turbo spools up fine, but as soon as that little needle tried going above 0, it just sounds like a cat with a furball....the only way i\'ve found to stop it doing it is to turn the engine off for half hour or so, let it cool down and start her up again.