TII Not firing (intermittent)

[pdtaylor18]

Well best give the full story first.  The car is a Jap TII Convertable in a S4 shell.  I say this because it now has a later S5 engine and the whole car has been re-loomed from front to back with a S5 UK spec loom including all the sensors and add ons.  I have had the car ticking over and i have had it to rev but i have had so many times when it either will not start, have had no idle and only goes if you keep the revs up.  put it down initially to the AFM but this did not cure it.  
to cut a long story short i have changed the complete upper manifold, coil packs, AFM, fuel pump resister, main relay, plugs, checked all vacuum hoses,changed fuel rail/regulator and the ECU.  I had it to idle once but seemed as if it was really rough but then noticed that i had left the AFM plug off. reconnected and started it but then failed to start. took the plug off and still failed to start.
 It has plenty of fuel as it smells but i dont think theres enough fuel fuel getting to the plugs as it is not that wet. I was expected a lot of fuel to come out when i did the de-flood thing but it was a bit of mist and that was it. plenty of good compression air coming out.
The plugs are new.  I do have spark but to be honest did not think that it was that good so hence the change of coils.
One thing is that i dont think that the pump is running when i start the engine.  When you use the check connector it runs but it does run until you stop it and plenty of noise from under the upper manifold.  So again hence the AFM as this is the trigger for the pump.  Gonna change the pump tomorrow as i have to change the sender unit as that is broken.  Not changed the filter but might bypass it. have not checked fuel pressure as i do not have a pressure check unit.

So I think its not enough fuel pressure but what else is there to get the pump working.  This car has idled and it has revved quite nicely and the compression does feel good as when it does start its first time.  checked all the earths and re-ground them.  So help please, anything else that i might have missed.  Not much else left to swop over or replace.  One thing i noticed is that behind the oil filler cap is a sensor with two vacuum tubes and a plug,this seems to be humming away all the time. I have replaced this but its still the same.
This is a lot i know but its just starting to get on my nerves now and i so want this to be ready for rs4.

[pdtaylor18]

When i changed the upper manifold i did as a job lot inc all sensors and BAC etc. I have not changed the ACV though.  Following the lead from the ACV and to where it plugs together directly above the airpump the connector has melted at some point. The pins are still ok but until i get hold of Nas to check the history not sure what has happened at some point in its life.

[grinder]

speak to adam hawker ( or track his threads ) - im sure he has a very very similar problem ??

[pdtaylor18]

yep have read pretty much all of them, seems a strange fault and especially as soon as i touch something i just seem to go backwards. Will have a look at the CAS and measure the outputs,it might be that. Apart from that not much left to change.  Could do with a list of the items that will stop the car from starting, I know the signals going into the ECU but not all will stop it starting, some are just reference and the ECU will have its preset ones to fall back on if it fails to see them. I know the AFM is a big cause but i have 3 of them and known make a difference.

[grinder]

i had this prob with the cab

we checked EVERYHING and it was all inline with what it should be - then found out the ECU was shot

i take it that Nas put the S5 AFM when he did the engine swap ?? - not sure if that could cause probs or not ? ( i think the S5 is round and the S4 is square - should should be simple to check )

so did the car run before you swapped everything out - or has it always been a non runner

[pdtaylor18]

no Nas started it up briefly but cos of no exhaust it was just to make sure it fired, which it did no probs. The sensors etc are all from a S5 TII.  Just that i had it going no probs and then as soon as you start touching something it does not work. convinced its a gremlin somewhere but just cant point to it right now. You can also start the car with or without the clutch pedal down ie it turns etc. swopped the leadfs around and even put another clutch pedal switch in but still no change. Everything is S5, the looms, etc etc.  just an anoying niggle that i will get to the bottom off.  Just need to chase the pump business, no way can it be an AFM as i have got 3 of them and have swopped the ECU and its still the same. Next going to start checking all the volts at plugs and ECU to make sure the circuit is doing the job.  Thing is Stu when it goes it starts ok, but its been a while since it started. just need a bit of time to sort the basics out, cross things off the list and do it methodically,only way to chase it down. Could be something blowing the ECU, if it is then i need to find out what before i go any further.

[grinder]

the clutch switch wont stop the engine starting - all that does it bypass the warm up system

when i was doing the cab i just sat with the manual and checked everything that was easy to get to

then checked all the earths and made sure they had low resistance

checked the ECU earth and made sure it was all OK

in the end - it had to be the ECU on the car as all the starting systems checked out just fine

you could build a check lamp - that should tell you what the ecu is thinking ( just 2 led\'s and some wire ) - i never got to this bit as we sorted it - but it could be a start

if the ECU is showing no problems then you know that its something else

can you make a bullet list of whats happening

for example

1 - put key in
2 - crank car
3 - car turns but wont fire
4 - remove key
5 - jumper fuel pump
6 - put key back in
7 - crank car
8 - car runs fine
9 - remove fuel pump jumper
10 - car stops and wont restart

this should make it easy for us lot to read and you to follow

if what i have wrote is correct - just make sure that Nas did the fuel pump rewire correctly

Stu

[FD3SNuttah]

theres two fat black with yellow stripe wires that are in the passenger footwell. these need to be to a connected to a switched live as they work on a negative pulse! so ensure you have these two connected bloody thing should fire up nicely.

the pump is fine mate. ive rewired it and it works! perhaps its that damn starter relay again!

hey you Grinder!! nothing wrong with my work that FC was running and you heard it running!!11

the fuel pump rewire is a "hardcore no resistance here, big balls i have" effort with it running its (fused) power directly from the battery with  a relay which switches on when the ignition is turned on. make sure that both of the two red wires that are in the engine bay are hooked on to the battery.

have a go with that lot and let us know.

[FD3SNuttah]

btw matey

you will know when the fuel pump is running, it makes a really nice whirry noise. the wiring was done so that the fuel pump resistor relay works exactly like stock. i just moved it to the rear of the car. i used the walk through from a website. i think it might have been fc3s.org?

if your getting fuel and you have spark and you have compression this car should start. id stick some fresh fuel in there if you havent already, i remember it being a bit of an arsehole if the tank gets too low a tenner\'s worth usually makes it happy.

funny you mention ecu\'s - there was nothing wrong with the ECU that was in the car, i know that for a fact, id be inclined to switch it back? some of these FC\'s are well wierd about which ecu you are running so it could be that too. theres a starter relay in this car somewhre which was causing me problems the last time, hense why i ended up doin my own wiring to the fuel pump and starter motor to bypass it. the problem was due to it having a previous life as an auto and wont let you start unless its in neutral.

everything attached to the engine is S5. including AFM.

btw when you changed the looms does the roof still work?  if you want to you can give us a ring after 7pm?

[FD3SNuttah]

i have been saving this pic for a time like this.

[grinder]

LOL

thats the prob Nas - you know the car inside out and he doesnt !! - it will take a while for him to track the wires and what each one does

its like on my cab - i have 2 purple wires that come off a fuse and into the dash and the other to the light relays - i know exactly what they do - but if/when i sell it - poeple wont have a clue !!

its like you mention about the 2 black wires - it would prob take him bloody ages to work out what they do and what they should be powered by

Stu

[pdtaylor18]

well success at last............................It was the spark plugs !!  Well changed the top two to 7\'s a while back(new) and the bottom leading looked almost new anyway and this had fired up no probs. I did change the Fuel pump for my FD one. Still no joy so i thought sod it,start from scratch.  Fitted 4 brand new 9\'s and it fired and idled perfectly. What did i learn ? well i got to know the car pretty well and in fact i think i am in love with her now.  You see the more time you spend underneath her and in her engine bay it gives some love back !!! LOL  Anyway it all goes now apart from the thermostat which is stuck so will rip that out tomorrow. getting the exhaust made from the downpipe and then that should be it.  It shows not to give up and in hindsight follow your instincts as i thought the spark was not much good but blamed it on the coil pack. How wrong i was.  Still got to change a lot of stuff over and its all goos practice. Thanks for the support chaps. Hopefully you\'ll see this at RS4 now.

[pdtaylor18]

Nas Just to let you know that everything is back to standard including the fuel pump relay etc. It was the best way for me and at least now i can steadily improve things as i go along now.

[FD3SNuttah]

nice one mate

im glad you was sorted. bit miffed about the plugs tho - they should have worked properly- i bought them brand new!

hey im glad it was a simple fix. Does it idle ok now? - edit you said it does! when is the MOT day? any chance we can go for a drive when its done? PWEESE

 Funny you should mention that the car gives you love - no bolts are hard to get off etc and its a joy to work on. unlike the FD where you seem to just swear at it when doin something simple like changing plugs!

hey don\'t fall in love too much i will want to buy that car back from you one day! lol - btw i have sent the log book off..

[grinder]

we will all be queing for a ride