Odd problem starting...

[Matt.Wild]

When I first got my RX7 a few weeks ago, I had a Power FC in it and a straight thro cat back.  Each time I got in it, it\'d start 1st time without a problem.  I\'ve since removed the Power FC and zorst (for insurance purposes ) and sold it and replaced with standard jobbies.

Since then, I\'ve had trouble starting her.  When turning the key, it sounds like its turning OK but fails to catch.  Its easy enough to get her to bump start and once done, pulls all the way thro the gears without a hitch to well over 100 (on a private road of course).  

She idles fine and sounds as sweet as a nut.  Since removing the bits, I\'ve only driven her locally as I don\'t want to get stranded anywhere if I switch her off meaning journeys tend to last about 10-15 mins at best (don\'t get me wrong, I don\'t drive down the street to the shops or anything!) which I guess may be coking some of the plugs up a bit.  I\'d love to take her to the red line for a bit to de-coke maybe but the weather @ the mo won\'t allow it

I\'ve read that the PFC fuels richly and in my estimation this could have fouled the plugs somewhat for when running on a standard ECU and thus caused the problem I have now.

Would it be a fair idea to get the plugs swapped for fresh ones?  If so, I take it I should get 7\'s for the leading and 9\'s for the trailing plugs right?  Also, what is the size of the socket on spark plug remover gadget that I need to get?  Can I remove the sparks without touching the intake that goes over them?

Any ideas other to the problem?  I\'m certain that its not compression as its only on 33,000 miles (55100 km) and was starting 1st time every time with the PFC and its literally been on the 2nd start of her (1st started without a hitch) she\'s struggled on the standard ECU.  The first time this happened I kept trying turn her over for about 5 mins odd, and the battery began to sound tired and chugged a bit

So, the only other thing I can think of is battery as my battery window on the battery says she needs a recharge altho it sounds to be turning over OK but not catching so I\'m not sure its this... mind you, after about 15-20 seconds the battery sounds tired and the local journeys may not be charging her enough to counter the starting.  

At a local garage today, I took her in got my cat back swapped for a nice quiet standard job and had to jump her to start on the slope leading away from the garage.

Plan of action is this: -

1 - Get a charger that\'ll cope with the Rex\'s big nasty battery
2 - If no joy, get a new set of plugs
3 - If no joy, scratch head and try to work out what is up

[clive]

Hi Matt,

Sounds like before you do any thing else you need a new battery, these cars do like a LOT of battery.

[sdminus]

Becareful of the rectifier in the alternator if the battery is getting low. They are mainly semi conductors of solid state electonic. although it is rated at 100 amps you can easiley blow it.
Somebody once told me it takes about 8 miles of driving to recover the power lost during starting the car. i would say more so on a rex which usually takes a second or two to fire. I would get the battery fully up to speed and do something about the stock return paths form the engine parts to the chasis.
scott:)

[Matt.Wild]

Right, gonna be charging her with the new charger for the next day or so to get her fully back up to speed.  If she loses charge again, i\'ll replace it

EDIT

Cheers

[Matt.Wild]

If I need to go down the new battery route, which battery should I go for?  What type/ampage is required?

[Matt.Wild]

OK, i\'m charging her now.  Should it be slowly charged or would it be ok to do a fast charge on her?

Slow is a slow and steady 2 amp (very slow I know ) or fast charge is 8 amps (much faster , but still quite slow ) but is a fast charge OK for a drained battery?

[mikeeech]

I\'ve recently needed a new battery as I had my car laid up for a while with the result that the battery would hold any charge at all. I jump started it from my 1.0 VW polo and it started first time, as it does every time.

Personally I would take it to a specialist to give it a good going over but then I\'m just lazy :p

It sounds as though it\'s running rich or the plugs could do with changing. The plugs should be easy to check though!

Out of interest, does the replacement ECU match the year of the car or wouldn\'t this matter?

What was the insurance problem with a power FC and decat?

[sdminus]

The ECU in question drove my car from norwich to santa pod in 90mins sat in traffic and drove home with no worries at all. 275 mile round trip using only 60 litres of optimax.
1993 fd3s standard engine build. only a few toys added for fun.
I would do a slow charge to avoid warping the plates in the battery mate.
scott

[Matt.Wild]

Insurancewise I have it down as a standard import hence the removal of the extra goodies.  I have no need for it to be modded and would rather have a quiet exhaust as i\'ve learnt that altho the extra power is nice, I just don\'t get on with the noise! :p

I\'m doing a nice slow charge right at the mo so to have the best charge possible.  Its only used at the weekend so a day or two (or maybe even 3) @ 2 amps prolly is best and from what i\'ve read elsewhere give the battery the best life (its a Bosch jobbie that looks quite recent).

To remove the plugs, how do I do it?  I\'ve changed plugs before but it just looks like a complete pain in the arse to get at them! Any hints or tips?

EDIT

Its a \'92 car with a \'93 ECU.  My understanding is the 92 - 95 had the same 8 bit ECU and 96 - 99 had the same 16 bit ECU and then 99 to 02 had the same ECU...

[sdminus]

You are correct in what you say matt
I think the 16 bit ecu has more pins on one of the plugs. so you cant interchange em
scott

[Matt.Wild]

Cheers for the confirmation

Just a couple quick questions: -

Would the plug stay \'wet\' after it been jump started and driven for 2 x 20 mins?  Could it be that they plugs are still to wet to restart her after turning off the engine?

I\'m gonna complete this full recharge @ 2 amps (would 36 hour recharge be ok or not long enough?) and if not sorted and still not sorted, i\'m gonna try getting some replacement 7\'s put in.  From what I recall, it had some new ones put in about 5 months ago and about 3000 km with the PFC.

What size spark plug socket does the spark plug take and how do I get at them as they look a royal pain in the arse to do!

Cheers :wave

[sdminus]

i cant remember what size you need mate.
i have 9\'s all the way round. always have done.
You can access the plugs from underneath the car on the passenger side. they aint to bad to do. when you get them out see if they are carbon\'d up.
Had a thought about this. you could try re-earthing the engine and its ancillary components. you may have a bad earth. also the pfc will let you take things away from the engine. You may have something missing. try reading fault code if there is one.
scott.

ps did you sort your electrical fault. it may contribute

[Matt.Wild]

How can I re-earth the components?  Not very electrically minded

Haven\'t sorted the electrical problem and have actually ponded whether its a grounding problem with those lights.  Would makes sense.

As for removed bits, what could have been removed?  As far as I can see, everything seems to be there that should be.  Knowing my luck, the PFC was set up in a special way with bits removed and i\'ll have no way of knowing which bits were taken out

Mind you, I had a problem with the dash lights before removing the PFC...

[sdminus]

I uprated my earths. with  a kit. take a few earth cables from various places to the chasis or back to the battery.  16mm H01 cable is what u need or a 16 mm multi strand cable. not 16mm multi  core which is what your house is earthed with. multi strand is finer. i put one to the slam panel. to the back of the engine. to the right side ( i think its a ignitor. near the abs). Cant remember where the rest are the car aint at my house. i may take the dog for a wlak and take you some pics. it made a big differance to my car it started better and went better. less restrictive. people over look electrical load.
scott
ps make sure its a semi pvc cable. never use rubber sheathed cable in a engine bay.

[Matt.Wild]

Where did you get the grounding kit from?  If I make my own, where can I get the crimper ring end to go on the end of the wire?