Sickly RX7!!

[Arnie]

Hi there peeps, I\'m not a big poster but I do check in now and then to have a look what\'s going on and maybe a bit of help searching!! I was wondering if anyone could give me a bit of help with a problem I have!! I\'m not overly mechanically minded regarding the intimate workings of the rotary engine, I usually leave that to Pip at WGT!! I have a basic understanding but not in depth!!
 
Basically, I\'ve just put my Rex back on the road after being stored over winter. Went for a quick spin yesterday and everything seemed fine. Had more time today so thought I\'d go for a proper drive as the sun is out too!! Basically, got two miles up the road, everything warmed up nicely so decided to stretch her legs a bit. As soon as she came on boost the engine started to stutter and backfire like a tommy gun!! I checked all the levels before I started her and I also checked the plugs and leads were all tight. The engine revs freely when not under load and not boosting, but as soon as it begins to boost while driving, the spluttering starts and she backfires.
 
Can anyone shed any light on this for me please? Any help would be appreciated.
 
Thanks in advance!

[Bobbit]

Could be rusty plugs or fuel cut kicking in. Have you used fresh plugs and fuel after the old gals winter snooze?

[Arnie]

Not changed the plugs but did use fresh fuel. She\'s due a service so was gonna wait till then to do the plugs. She runs fine until the turbos spool up, if it\'s the plugs would that not cause a constant problem no matter what the revs/load on the engine??? As I say, I\'m not aux fais with the intimates of rotary engines!!

[Bobbit]

If the plugs are old then the extra air/pressure caused by the turbos coming on boost can be enough to disrupt the spark and cause your problem. I\'d suggest taking the plugs out and giving them a good clean with a wire brush or simply changing them over if you can. If that doesn\'t fix the problem and if you\'re still on stock twins it could be a sticky solenoid or a loose/split hose in the rats nest. Try the plugs first but if the problem persists and if you feel confident try checking out the pipes, if not Pip will get you sorted no probs.

[Wombat-007]

Sounds like ignition breakdown for whatever reason. Could be as simple as buildup on the plugs after a long layup.
I\'d take it for a decent spin off boost on the motorway for about 30-40 mins to clear the buildup then when run in, try it on boost again.
It\'s common for ignition to seem fine at idle/light throttle, but fail under wot/boost when more is asked of the ignition system.
 
Keep us posted on how you get on

[Arnie]

Cheers guys. Will have a look tomorrow as I\'m busy for the rest of today. I\'ve spoken to Pip and he seems to think she\'s going into "limp" mode. He reckons it\'s probably a sensor gone down somewhere. I\'ve booked it in for him to have a look, but if I get it sorted in the mean time I can just change it from a diagnostic session to a service and power run!! Time will tell!!
 
Am I right in thinking that the easiest way to get to the plugs is through the passenger wheel arch??

[Bobbit]

I always go from the top, unclip the I/C pipe then take the Elbow off, you\'ll see the plugs down the gap, one at a time and you\'ll be finished within the hour.

[Arnie]

Cheers!! Much appreciated!!

[Arnie]

Well, sorted the plugs today, talk about awkward!! Oil lines, brake lines, power steering lines, air con lines, vac lines and god knows what else in the bloody way!!! Anyhow, they weren\'t too bad really, the bottom ones in each housing were slightly corroded on the lead end, but nothing major really. They were all a bit coked up as you\'d expect but again nothing major there either. Cleaned them up, even cleaned the connection on the leads using a nifty little wire brush my Dad uses to clean corroded terminals on PCB\'s and such like. Took her for a spin and........ just the same. Looks like it\'s either a split/loose vac hose or a sensor gone. Booked her in at WGT so will find out for sure after Pips had a good firtle with her!

[RXSpeedy]

I had the same symptoms on mine a while back, was fine on idle and off boost but as soon as i put my foot down massive backfire and lack of power. I checked all the piping and IC pipes..... i followed the piping down to a jubilee clip that upon looking at seemed fine but i thought i\'d tighten it to see if it moved... turned out it moved about 2 turns on the ratchet. Test drived the RX again and hey presto the car was perfect.

Id check all the ic piping before riping off uim for the rats nest though that would of been my next place to check.

[Arnie]

All IC piping safe and sound. Don\'t have the time or patience to start looking at the rats nest atm. Mega busy at work and in the middle of decorating too! As I said, it\'s booked in at WGT next week so I\'ll just have to wait for then and let Pip sort it!

[Arnie]

Well, dropped her off at WGT this morning so should have some news by the end of the day!! She\'s in good hands so all should be well, I hope!!

[ChrisDubbya]

Keep us posted!  I have a very similar sounding problem, mine is booked in with Jon @ atomicrex for Tuesday so would be good to hear how you get on, might give some clues as to what\'s up with mine :o

[Arnie]

Right. It\'s the oil metering pump!! As mine runs a Knightsport ECU, it puts her in limp mode, as opposed to an Apexi which will make you aware of it but let you still drive it!! You just have to put oil in the fuel without it working. A new one is circa £1500!! Pip thinks he has one somewhere or will be able to get one for me second hand. Much cheaper!!!! Failing that, it would be cheaper for me to get an Apexi, remap, and shares in BP!! Hopefully be sorted in a couple of weeks so I can finally take her for a "spirited drive"!!!!:3gears-rh