Hi all,
posted this originally and thought problem was resolved after fitting a HKS Twin Spark Amplifier!
But still after driving normal or flat out for more than 15 mins car becomes hesitant like a break in ignition, coils etc. Changes coils can\'t confirm these are 100%, new plugs fitted, have new leads to go in on the weekend.
Was advised by Clive at mazdarotaryparts that I would need to keep engine cool with a vented bonnet, to lower intake temps, and that the intake temps are the problem, done some research into vented bonnets and cooling efficiency and the results are not to good in comparison to standard bonnet!
Also some regular track attenders and 1/4 mile loons use up to 11.5 plugs in the trailing side of the rotors, and will look at taking mine from the 9\'s up to a 10!
I see a few people have suffered from this on there FD\'s is there something i\'m missing? Is this something that will show as a fault code?
Many thanks
Anybody here?
Might be worth getting in touch with some of the rotary specialists in the UK, it seems as though it could be almost anything as you\'ve changed the obvious stuff;
Guess it could be
-Plugs
-Leads
-Coils
-Wiring/Earthing
-ECU fault
-TPS fault
-Vacuum Leak
Also is it standard?
Just read you HKS twin spark install post..
What ECU are you running?
Just running a standard ecu
Gonna put 10\'s in trailing and new Fujita leads in this week
The car was standard when this started!
Now running a cat back exhaust and blitz filters waiting for new ecu, fuel pump, injectors etc. But want to try and solve this problem first.
I can trace it back to running the car into the rev limiter on Quarry Corner @ Castle Combe, been fine for 2 whole open pit lane track days but obviously didn\'t stay on track for longer than 15mins
Once i visited the Nurburgring and jumped straight on for lap 2 thats when hesitation began, let it stand for 20 back on and it would be fine?
I should take it to Geoff but just don\'t have the time or money this month is it something that should come up as a fault code?
Sounds like its going to be a heat issue - visually, are there any signs of heat damage?
No immediate signs of heat damage, have replaced a few vacuum pipes that run above the turbos, they were original, and had heat damage, but after taking off the plenum and investigating the rats nest all other vacuum pipes seem fine!
Have had a little chat with Tim again at RXmotors and have been pointed in the route of the positive wire that runs to the ignition amplifier, as the light on the HKS Twin Spark is on but not 100% bright!
This could be the problem? Fingers crossed!
List of changes so far:
Ignition Amplifier
Coil Packs
Sparks plugs 9\'s Trailing and leading
Added HKS Twin Spark
To come:
Spark plugs 10\'s trailing
Fujita High Tension leads with grounding cables
New live/positive feed to original Ignition Amplifier
Slowly but surely going to solve this
Many thanks for your time
Have you checked the pulsation damper at the end of the fuel rail - these can fail with some odd faults being the symptom.
Would be good to add pictures on the install thread as planned but i can\'t add pictures until i become a full club member i think!
I will have a search in the workshop manual for the Pulsation Damper, guess its simple to find as its on the fuel rail? Does this act in addition too or in a similar way the \'Fuel Pressure Regulator\'
What are the signs on a failed PD unit?
Depending on how bad the failure is you can get a strong petrol smell (more than usual for a rex) - really extreme you get a fire :flamed
But one thats split can let air into the system. (Expansion when hot could make a split worse) IIRC its not too bad to get at, so give it a clean up and you should be able to tell pretty quickly if its split or not.
Now that is very interesting, im yet to smell it but the day before yesterday my missus arrived at work in the Mazda and she could smell petrol she also had a comment from her work collegues of a strong smell of fuel :eek:?
The next day I took the car out for a 15min run but did not experience the smell?
How much are these?
Can you just confirm what IIRC stands for?
I understand its part of the intake system is that correct?
If
I
Remember
Correctly
Trust me to search the site and find \'IIRC on the intake system\' ahhahahahahahahah
:rollin
What does the PD look like?
Also just looking into the \'Double throttle\' and how many people have disabled it or removed it as this could cause boost/hesitaion problems!
Worth looking into?
Had a little look into the Fuel Pulsation Damper looks very similar to a FPR, quite expensive to replace!
Will check this as soon as possible
Ok new leads are on..
Problem is now apparent immediately while on WOT under load???
All fine on WOT off load?? Which is leading me to maybe over boosting?
Also checked Pulsation Damper and all seems fine, no sign of cracks or leaks!
Will be sticking on the defi boost gauge and see what its running at!
Anyone have a boost controller for sale?
Just looking into other threads with similar problems, and the battery and voltage to fuel pump has been mentioned!
My car still has the original battery from Japan, could be worth replacing?
Right.........
Woke up this morning went to start the RX7 and no fuel getting to the injectors, cannot hear fuel pump priming but the fuel pump fuse is fine?
Guess its a brake in the Live wire? Had a similar thing happen on the Subaru a couple of years ago! Rac routed a new live so gonna get a lift to work and sort when i get home!
Any other ideas?
Sounds similar to something I had, and after some investigation, we simply replaced wiring to the fuel pump, and then a secondary live feed to the ignition amp, and all was solved...
Hi Aceman,
could you explain how you ran a secondary live to the ignition amp, Tim @ Rxmotors has advised on this, and want to get it right if i do it!
Have power/voltage running to connection above fuel pump, will need a new fuel pump unless one of the wires on the actual pump has worked its way lose?
Thank you
If I understood it, I\'d let you know..
Haywood rotary fitted it! I think it\'s simply a wire from the battery to the ignition amp (somewhere on the circuit board box thing on passenger side by the ABS) with a relay in it running from the ignition (to cut the live feed when the car is off)..
Make sense?
Can\'t take photos for you sorry as car is in the garage for a rebuild..... :(
I don\'t like electrics.
So its just one extra live wire connected to the battery live, onto the Ignition Amp live, with a relay in between it?
Any more info on the secondary live?
Ordered new fuel pump as this gave up the goat yesterday, uprated of course! Will fit when it arrives and report how the car is!
Could have been the whole problem all along, as the fuel pump would be working harder once warmed up, and could have been breaking down for months!!!
It is the standard original pump so fingers crossed my problem is sorted after this????? :Grrr
Going to put a BNR33 uprated pump in on the weekend, just until my new one arrives!
New Sard 280ltr fuel pump fitted and the car started fine, took it out for a drive and all ok.
Woke up this morning to take the car out in this lovely sunshine and again not starting - lack of fuel and pump not priming.
Checked all relevant lives - 11.9v to fuel relay, 11.9 to fuel pump fuse, but nothing running to top of fuel pump.
Indicates a break in the line which didn\'t show up with the RAC - 11.9v when they checked to the top of the fuel pump - argh
New live run from fuel pump fuse which had shown 11.9v, checked again and it dropped to 8v then checked the live from the positive on actual pump and it was reading 11.9v? Is this normal?
Put it back together and took it for a little run, had fuel cut on \'wot\'!
Reset the ecu and took it out again and all is fine will confirm if hesitation returns but fingers crossed this is it.
Oh and now have a small coolant leak from the bottom of the pipe that runs through the plenum argh, if i could afford a newer RX7 i would buy one right now lol
I\'m going to run a new live from the ignition barrel to the ignition amplifier will this be ok?
Could i run a secondary live from the fuel pump fuse line?
Can the secondary live be taken from any other live or will it affect/drain the voltage if you have two particular units running off the same live?
Many thanks
Running two post\'s effectively on this hesitation problem!
Attached a new live to the fuel pump but still not got round to attaching a secondary live to Ignition Amplifier!
But to let you know i have taken the FD3S on a long spirited drive as you would on track and guess what??????????
NO HESITATION WHAT SO EVER WAHOOOOOOOOOO!
Many thanks to all and hope this may help someone else in the future?