Ok so after spending silly amounts of money replacing the ignition coils, the car still has the same problems, except not so bad.
Basically driving along, the rev meter will go straight down, then kinda come back up and the engine will judder. also Sometimes when going slow the revs will go and then the engine will just cut out and the lights will all come on. The when i try to start it will fire up then die straight away, and then sometimes it will just work.
At the moment i think its a bad connection behind the dash. Is there anything else it could be? I really don\'t want to be pulling dash out, I NEED A CAR :(
thaaanks
Have you checked all the earths?
don\'t know where they even are tbh. Do you have a rough description?
oh also. Apparently the ignition coils for the egi are the same as ones for a beetle?!?
Should be one coming from the top of the inlet manifold going to bulk head, another near the engine bay fuse box.
well they seem to be fine, though they\'re looking a bit puney!!
You do have the leads on the right way round, right?
i guess so? When the revmeter isn\'t playing up the engine is flawless.
Hmmm too busy to think at the moment - give one of the specialists a quick call - could sort you out in seconds :)
:wave
i did, they want me to take it in for an hour, which will "only" cost me £70 just so they can look! At that price i might aswell just take the dash apart myself and have a fiddle!
cheers for the help anyhu brett, i\'ll see what the electrical guru\'s have to say, then get set on taking it apart!
i cant see the revmeter causing all the probs - sounds like you have more issues to be honest
have you thought about running a MASSIVE earth lead from the battery to the shock tower ( i did just as an extra measure )
im sure if you search on here there are some diagrams which shows you all the main earthing points
there are the ones that brett says and there is one ontop of the gearbox aswell - not sure where the rest of them are though
have you checked the ECU earth - as i know that when i killed the ECU - the first sign of that was that the speedo and rev counter dropped to nothing - so thats a simple thing to check ( big black lead on the ECU harness in the passenger foot well )
i know it sounds silly - but do you know what wire runs the rev counter - as when the car is running right - if you disconnect this - does the car still run - if so you know its got naff all to do with the rev counter or this wire :D
that cutting out and starting issue sounds like a bad connector on the AFM - mine was lose and gave similar symptoms on the TII.
It does sound like a dodgy wire - perhaps it\'s time to \'waggle\' some wires and see if you can trip it up. Just go around systematically giving each of the sensors and so on a little tap / nudge / wiggle - what ever seems appropriate for the connector. Anything lose is going to show up right away.
right then after reading the best part of 25-30 pages of threads , i found the link i was looking for ...
http://www.rx7club.com/showthread.php?t=586921
this shows all the earthing points on the FC3S :D
Revs comes off the coils does it not? did it do this before you replaced the coils or is it something that was there before. I think i did read your initial post about this problem and some may have pointed towards the distributer but you seem to have got it going so I guess it was not that. I do have a spare distributer you are more than welcome to try and see if the problem goes away(just pay postage) but you can have it for £20 posted, no cap but its all there and good as a spare.
I would imagine the rev pick off from the coil going to the ECU/dash may be at fault but i do not have a wiring diagram so any best guess. As Dave said its now the time to start moving a few wires and see what happens. If the earth was bad I would have expected you to have other problems as earths are shared by many components and few on any car are dedicated apart from things like starter motors.
Does the revs go up and down as well in tune with the needle or is this purely a dash related problem? It may well be your clocks?
Cheers guys. Don\'t know if you know grinder but the rev counter is actually linked to the ignition coils somehow, so this could cause the symptoms, well that\'s what the aa man said after looking at a wiring diagram! I\'m currently out so I\'ll look at it all in more detail 2mo. Oh also the counter doesn\'t always just drop, sometimes it kind of fluctuates, always under reads though. Thanks!
I think your coils might have a spare \'rev\' cable connector on it but you could find where the pick off is and run a seperate wire all the way to the ECU. Tried looking at an online diagram but it was a pain to try and read sideways and upside down!! The one thing i am not too sure on is where the signal splits as it does have to power not only your ECU but you dash and cruise as well. I highly suspect all that will come from the ECU. Even if you dont have cruise the wiring will be there.
i cant see why you would need the rev counter to work for the car to run - it just seems dead strange to me thats all
if the rev counter is linked to the ecu - can you not meter it out at the ecu - and see what voltage you get from it ??
if the rev counter is playing up - the meter would show the voltage changing aswell
then its a case of chasing wires :(
Bang on mate, I think we need a little more info as to what the engine is doing in relation to the rev needle. You do not have to have a working rev meter for an engine to work, however if that rev/RPM wiring is faulty all the way from the coils then the imput into the ECU is also wrong and that will upset everything inside and also the outputs. I think Daves initial diagnostics for the cutting out is an AFM is highly likely the culprit but this could also be linked to a fuel pump. I had almost the same problem on the white FC and it was the pump. In this case he is seeing the needle go down or bouncing,engine juddering etc and thats because it is,his engine is probably on the brink of cutting out, so there is probably nothing wrong with the meter or rpm side of it as this is just the symptom and not the fault. His original post was about cutting out and similar fault as above and it looks like nothing has changed.
Apart from wiring lets look at a list of items that could cause this and hopefully he can check them one by one and get to the root cause.
Coils
Distributer
ECU
AFM
Fuel Pump(inc relays etc)
Fuel filter
The only way to check most of the above is to swop stuff over but you should be able to get resistance and voltage checks and most of the above to check correct. Coils rarely go wrong,same for ECU\'s as well unless they have got wet. I would focus on AFM/fuel and they are relatively simple things to test.
hokay, the cars completely dead now. Starter works fine but the spark plugs just arn\'t getting anything.
pete: thanks for the offer but i don\'t think its the distributor as the leads going into it arn\'t getting anything. Also when the rev counter fluctuates it doesn\'t affect the actual revs on the engine, though it will judder/misfire sometimes.
grinder: thanks for looking though all those threads, legend :D
prof: tried wiggling some wires and it did actually seem to help, but now the problems gone too far. As for the AFM, would that that really stop the spark plugs sparking? I shall give it a look anyway!
got a few days off work so i may just just taking everything apart and putting it back together:D got nothing to lose now.
edit: just read your last two posts, i shall have look. Im guessing checking all these things will be in the haynes manual, so i\'ll get on it, then start chasing wires. Just to clarify, sometimes the rev counter would drop off completely and i would be driving for up to 10 minutes without it. Also its good to know that that is likely to be a symptom more than the fault. cheers guys
Theres also the main relay if the EGI\'s have it, TII\'s are by the charcoal canister area, theres also a relay under the steering colume,again I can only assume its roughly the same as TII\'s for the basic stuff in wiring and relays etc. The one under the steering cowling is black/yellow in colour. If you need any of those then send a pic of your old ones and I will gladly send any of that stuff as i do have quite a few.
If its completely dead then at least you have to start with the basics now:
Dead why? do you have fuel pressure? do you have spark and where at?
if you are not getting spark to the distributer then the problem lays at the coils or the power going to the coils. Something worth looking at is your main EGI fuse,make sure thats in and a snug fit. Good luck and keep us imformed as you go along. I will have a look at the diagram and see if there are a few pointers for you if you have no luck.
dead as in it just wont fire, its not getting any spark. Checked the fuses first thing and they wern\'t broken, could be different now that the problem has worsened
Just been looking at the wiring diagram for the EGI - the coils and injectors get there feed from the same power source, which comes from the main relay - the one tucked in the corner by trailing coils - it has 2 feeds coming from it - one feeds most of the 12v power in the car - ECU etc, the other one is only used for the coils and injectors.
On the passenger side shock tower, there is a small black capacitor - the wire leading to that is also connected to the same voltage source - if you can get a multimeter on that and check that you have 12V there.
The tach take off comes from the rear coil, but the coil gets the signals first from the ECU - and then it\'s passed to the other circuits (rev meter) etc.
if you get the full manual it will tell you what ohms / volts you should get on most components - so might be worth having a read of that - and then just checking everything has 12v
is you car making any funny noises ( clicking etc.. ) - i went thru a 14 page thread trying to get my cab to run - in the end it was the ecu :(
but i checked SOOOOOOOOOO much stuff it was unreal
its a pain now i know - but once its running again - you will have learnt soo much stuff
i think they main thing is to try and get one thing working , then move onto the next etc..
so start at the relay that dave said - or even the ECU and just starting tracing wires
ok havnt been able to get much done, been busy grrrr.
anyhu, coils are fine ive just checked them and im about to look at the crank angle sensor/distributor. anyhu, my dad looked through the wiring diagrams and seems to think that connector f39 could be a problem. Can anyone tell me where this is/how to locate it?
thanks :D
ok, having troubles checking the distributor. Its different to every manual i have!
right it seems the s4.5 ignition system is different to every other FC!!!
look
(http://img9.imageshack.us/img9/6491/pict0003nou.jpg)
these are only ignition coils i have, all the other cars seem to have more.
Anyhu, ive managed to check the 2 cables going into the distributor and thats fine, as for checking the distributor itself im not too sure on how its done, as i don\'t seem to get any readings when checking it ??
also prof is this the place you were talking about with the relay and the cables?
(http://img4.imageshack.us/img4/3228/pict0002ulp.jpg)
not sure what i need to check and where tbh, my electrical skills are somewhat limited :P
thanks again
ok the car has decided to start working again now.... if its working how can i test for faults?
Quote from: dthebuk;598213ok the car has decided to start working again now.... if its working how can i test for faults?
Going to be difficult to do that :(
That pic is the Main relay - I was looking at your ignition circuit - and you kept talking about distributor - then it dawned on my that your car isn\'t wired up the same way as an N/A in the field service guide.
Your dizzy sits on the worm gear that would normally have the CAS sensor - and because you have a Dizzy - you only have 2 coils - not the normal Leading / Trailing coil setup that we have in the S5 Cars. The Service guide - and Haynes - show only the US setup - with fully electronic ignition.
Not sure what provides the signal to fire the coils - is there some low voltage take off that goes to the ECU off the Dizzy ? Likewise the injectors would need a similar (the same?) signal to fire also. I don\'t think I have a circuit for a dizzy setup with ECU.
Well what did you touch to get it working again?
I have an S4 main relay mate,send me your address and i will pop one in the post for you, no good to me as the connectors are different for the S5 ones, at least you will have a spare.
Quote from: Prof;598218I don\'t think I have a circuit for a dizzy setup with ECU.
does such a diagram exist?
thanks for the offer pete, i might just take you up on that, ill send a pm in a min.
i had a play around with the wires/connectors in the second picture i posted. Is this where the relay you suggested is prof?
And another update, i just took the car out for a drive. Its not completly problem free but the problem is now different. Occasionally under acceleration at around 4 - 5.5 krpm the rev counter will start going crazy (inbetween the two readings) and will over read. Though has no effect whatso ever on the engine. The rev counter did not drop once and the engine was running smooth as...apart from the horrendously loud backfiring :D
Quote from: dthebuk;598252does such a diagram exist?
thanks for the offer pete, i might just take you up on that, ill send a pm in a min.
i had a play around with the wires/connectors in the second picture i posted. Is this where the relay you suggested is prof?
And another update, i just took the car out for a drive. Its not completly problem free but the problem is now different. Occasionally under acceleration at around 4 - 5.5 krpm the rev counter will start going crazy (inbetween the two readings) and will over read. Though has no effect whatso ever on the engine. The rev counter did not drop once and the engine was running smooth as...apart from the horrendously loud backfiring :D
Yep that metal can thing is the main relay.
The 2 smaller wires are the relay coil, the other wires make up the 2 main circuits. I\'m guessing the coils / injectors will still get their 12V feed through a fuse and that relay - so it should be possible to test that bit of the circuit and at least prove that part is working. Beyond that I\'m a little in the dark on this one.
If I remember right from my piston days that some of the older cars the distributor did send the rev signal, you may have more than one fault here by the way. Tell you what I will send you the distributor,try it you have nothing to lose. If it works then my treat but if its no change then just give it back at RS or another event. I will dig out any other S4 stuff I have but most was for a TII so not even sure if it will be compatable.
The distributor I have is definately an EGI S4 item.
ah nice one. So was it the american S4\'s that have the different ignition set up? or is just the later s4 cars that have it?
Judging by the way the rev counter is moving id guess its a problem with the rev counter its self. Its like a bad speedo that isn\'t stead but slightly worse, if that makes sense? With the earlier problem the needle always seemed rigid.
Thanks once again pete!!
Think some of the Australian ones were like the TII setups in coils and CAS, not sure on the USA market but most seem to be like the TII\'s. Been trying to have a read and most non rotary sites say the rev comes off the coils which I know is correct in the majority of cars but I am sure I read somewhere that a Distibutor can as well. If we can be sure of a S4 rev gauge and S5 being compatible I could send just that part as well. All mine are S5 and I know are not but/however the rev gauge just might be by itself. It might even be worth asking if someone has a S4 ECU you can borrow or buy cheaply, they can break over time.
well I had the as out again last night and the problem seems to have changed, the car sparks but will not run. It\'s runs on east start fine so the aa man thought the car was running to lean. It\'s still having problems with the rev counter though. So the man seems to think the problems with the fuel pump or a main relay or the ecu. He also mentioned worn rotor tips. Meh I\'m getting to the point where I might just take it to a garage, but I\'m begging the the think the garage broke it in the first place! :(
Shall i send a fuel pump as well? I have a working one you can chuck in. Dont go to the garage just yet for silly things that will cost a fortune to get sorted.
Any items you dont need just give em back at a later stage.
The only thing i dont have is an ECU.
right been having a good rummage,got a fuel pump but the main relay I have is for a S5 and although it would work the connectors are different. I can still send this and you can splice and do what you want with it. Usually though this relay either works or it dont. You should hear a click from it as you turn on the ignition. I think at this stage its looking at pump or ECU. You will have to go down that route before you suspect the engine. Also if it were tips then it would not be intermittent as it is now so i doubt it is.
The rev counter could be just that...... the rev counter and nothing more and could be unrelated but we\'ll sort that one out when the car is running 100%.
ah nice one pete, if you could send the fuel pump that\'d be great. Ill be more than happy to cover postage for anything and if you send us a part that fixes the car ill be more than happy to pay you for it :D
Hmm the car does click, but thats most likely the starter solenoid right? Ill need someone to listen to check if its the relay. Glad thats its not likely to be the engine :D
The only thing with the rev counter is that the problems occur when the problems with the rev counter occur, so hmm. Thats why id pretty much ruled out the fuel pump. To be honest ill try anything atm, and if you\'re willing to send me parts i have no reason not to!
I\'d say ECU then at this stage.
I will get the box out tomorrow for you,theres a few other S4 bits in there but no good to me. I have not sent the whole distibuter but the little black boxes of them as thats the common thing to go,also they are plug and play and no need to set the dizzy up if i sent the whole thing.
The pump is a TII one but will fit and give you a bit more fuelling than a EGI one but they might be the same being as they share virtually the same injection system. I\'ve sent some inline crimps as well, these can be used on your fuel pump as well if you have to.
If the car starts then its not the relay,however you need to make sure its not getting lazy and switching off but i think with everything you have said and some of the diagnostics you have done already then it may well be the ECU. Did you swop the coils?
ok sounds good, though the ecu is probably the one thing i don\'t want it to be as im guessing it will be an absolute mission for me to find a replacement. Once again thanks for the help, the problem doesn\'t seem so bad now!
Yes i did swap the coils. After i swapped them i did over 100 miles without it breaking down on me, though the car had been standing for about 2 weeks, which seems to help.
the ecu should be a dodle to find a second hand one - just look for someone breaking an EGI on ebay - and it shouldnt cost you a lot
i spend about 10 weeks trying to start my car to find it was the ECU was shot :(
just waiting on the ecu at the moment, so i thought id check the fuel pump anyway ust to see if that is the problem. I put my hand on it the see if i could feel anything whilst someone turned the engine over and i couldn\'t feel a thing. Is that a sign of it doing nothing? Also i was planning on taking off one of the fuel lines and having somone crank the engine so i could see if it was actually pumping anything. Is this a good plan?
thaaanks
You can do that at the engine side if you want but have a container to catch the fuel in. Dont forget that just because you have fuel it does not mean its pumping at the right pressure but i suppose you will soon know if it only dribbles out.
The pump should at least prime when you turn the ignition on or if you find your green test connector ,if you jump this then the pump runs all the time(for test only).
It has sounded like the CAS might well be playing up. The T2 engine I bought for the S4 had similar symptoms to yours (would drive along OK, but sometimes cut out). During the work, I noticed the wires from the CAS had perished, and the insulation had flexed away - which meant it could short quite easily. This could certainly cause the issue by not telling the ECU when to fire the sparks at all, or erroneously...
ah another new idea. Awesome arch. Whats the CAS? never heard of it.
And pete, surely i should be able to at least feel the pump vibrating a bit? i litrally couldn;t feel a thing. I\'ll give it a try engine side . thanks again team
(http://www.archbish.com/pics/cas%20tip.jpg)
(http://www.archbish.com/pics/cas%20tip2.jpg)
This is where it is. 4 wires come out of it, and on mine, two were stripped and their shorting may well have been the problem.
oh bad times, i don\'t have a CAS.
daaam is that your fc? more pics please, i like that alot!
edit: thats not an fc is it?
Thanks dude - it\'s an FB. :D
You don\'t have a CAS? OK - I\'m lost, I thought pretty much all rotaries had one of these in. How does it know the position of the engine? (I\'ll scorn anyone that says "it\'s under the bonnet...")
oh, OK...
"Starting in 1986, a crank angle sensor replaced the distributor. The crank angle sensor looks like a distributor, but instead of a cap with wires at the top, it has a removable inspection plate. Because of the crank angle sensor and loss of the distributor cap and rotor, these ignition systems are known as distributorless. "
At least that rules out a dodgy CAS then... *grin*
And i also sent him the electrics out of the distributor so that should well and truely sort that out if it was.
The pump is told to run by the main relay and via the AFM so make sure thats working. A dodgy AFM is the cause of many a problem and often overlooked. The only true way is to get a multimeter and check the resistance and volts across the pins.
ok up date. Checked the fuel pump. Thats fine. Turns out the problem is trailing (these are higher up on the block) spark plugs are not sparking. The feed that goes into the distributor for the trailing plugs is not sparking. The coil is running the correct resistance to. This would explain why the engine would run on easy start. The rev meter is also not moving at all when cranking.
So we think the problem is somewhere between the coils and the distributor as one of the pick ups is getting nothing. Just making a wire so we can swap the pick ups to see if its the pick up thats the problem.
This is beginning to look promising, no chance any one has any circuit diagrams for my car is there? Trust mine to be different :P
Also just about to use the pick ups you sent me pete, ive only just now discovered what they are :D
cheers guys
Interesting as i think prof said the rev counter bit comes off the trailing coils?
Also those pickups were mentioned wayyyyyyyyyyyyyyyy back in your thread. Hope it is one of those as thats an easy fix.
Quote from: pdtaylor18;602417Interesting as i think prof said the rev counter bit comes off the trailing coils?
Also those pickups were mentioned wayyyyyyyyyyyyyyyy back in your thread. Hope it is one of those as thats an easy fix.
well it was those pick ups. THE CAR NOW WORKS :D:D:D:D:D
I think the problem was that only one was checked, meaning the broken one wasn\'t touched at all. Also the AA man was adamant that the problem was fuel, so i gave up with looking at the electric side of things. It did run on easy start, but i guess it probably didnt need all the spark plugs going for that.
anyway! words cannot describe how happy i am :D cheers for all your help guys. And thanks to pete for sending me the right parts. I\'d quite like to keep the fuel pump pete, don\'t mind paying you for it. I think i was actually going to buy it off you a while back. So tell us how much you want and ill pay pal it. Don\'t mind giving a bit of money for the rest of things either :Thumbs-up
guess i\'ll be going to brooklands :D
That is fantastic news mate and good job i had a dizzie spare as those alone are hard to get hold off, How about if £25 sounds ok as it did cost about £6 to send the box of tricks and the pump is a good TII one. All the other bits you can have on me. Paypal will be just fine.
To be honest i am just glad you got it sorted,easy thing in the end but wow does it cause some grief.
Nice one fella. Glad your all sorted. Now for some sideways action!
Quote from: TiddlesRX7;602471Nice one fella. Glad your all sorted. Now for some sideways action!
haha this ones not suposed to go sideways!!! though admittedly it just did...quite a bit :D
pete i shall send you the monies :wave
I thought there all ment to go sideways! or is that just me?
dunno where you got that crazy idea from ?!?? :Hammer