Injector Wiring and Connecters

[F129RLU]

Hi,

Me again. I'm sorry i seem to be asking a lot of questions.

I'm still having trouble with bad running.

So far i have

1, Replaced Throttle J Plate
2, Cleaned Airflow meters
3, Cleaned Idle Control Valve
4, Disconected Throttle Pot (No Differance)

Car recently had new Dizzy, Plugs, and Leads. Coil Looks pretty new.

And yet its still hesitant below 2k revs. Trys to cut out when you touch the throttle.(never does though)

Thinking about redoing the Wiring and conections to the Injectors????

Just doesnt drive like it should. Its very sluggish and jumpy when pulling away.

Any Ideas???

PS If i can offer any advice to anyone. I run an IT company in my spare time, so throw your computer questions my way. Feel like i need to give something back!!

Cheers

Oh also, i dont know if this is normal, but i have a kind of electrical buzzing when from the coil area when i blip the throttle. Quite quiet, but definatly there.

Edited by F129RLU on Sunday 3rd August 22:13

[Barkychoc]

I'd have said either throttle pot (I think you've ruled that out) or a leak on the pipes between the airflow meters and the plenum (some air is getting in that isn't being measured).

This assumes airflow meters are in good working order - I assume you have airflow meters (S3c doesn't).
I think you can swap the leads over on the airflow meters to see if it changes.

[mikee boy]

Following advice from this site I checked the temp sender unit (and found a poor earth) and cleaned the 8-way plug near the coil (full of white grease, but now not). It now idles perfectly and has better responsiveness to the throttle.

I also did everything on your list and is got a little better each time, but I think it was the temp earth and the 8-way that made the final difference.

Good luck

[ketvrin]

from my recent experience, I would check the vacuum pipe from the throttle (just below the TP) to the fuel pressure regulator too, check for missing or worn connections, splits, and nips in the bends...

K

[ketvrin]

Just remembered - I think Graham had a problem way back with the vacuum pipe from the plenum to the brake servo and that caused lumpiness... another one to eliminuate at least ?

K

[Mr Clifford]

"Thinking about redoing the Wiring and conections to the Injectors????"

Agree, although a garage did mine they only took one hour to take the connector `box` off, checked the wires, they were badly (green) corroded, cleaned off the wires and fitted a new connector (about £2) and the car went like a dream. No loss of power or kangorooing !!

Before this i had changed plugs, air filter, cleaned AFM (but these were clean) new leads.....ah well, at least these bits wont have to be changed for a while !

3 months of rough running sorted within one hour !

[GreenV8S]

I would suggest doing a continuity check back to the ECU if you're considering this. It's not hard to replace the connectors, but there are quite a few of them so it is s significant amount of work altogether. To add to the problem, if the terminals are corroded the wires will probably have corroded to, which could easily mean you can't replace the connectors unless you also replace the engine bay loom. That's a much bigger job and not something you want to get into if you can avoid it.

[F129RLU]

Yeah all great info.

I've got a throttle pot and 2 airflow meters coming this week. So i'll do them first.

Could anyone tell me how i can tell if i need to rewire for this new throttle pot?? I shall also be after and idle control valve if anyone has one for sale.


Cheers

Ian

[sphs2]

Ian, i had running problems, what i ended up doing was going to halfords and buying a gunson falut code reader. Check whether you have a 3 or 5 pin connector near the ECU (not the one with the red cover) then go and get one, it cost me £9.99.

Unplug your ECU for 5 minutes then reconnect, then simply follow the fault code reader instructions, if you have any sort of engine management fault it will tell you straight away, mine was down to a bad connection on one of the air flow meters which was fixed in minutes.

[F129RLU]

Still having problems.

I've replaced the Air Flow Meters and Throttle pot.

Got it to idle smoothly and drives fine for about 10 mins, then it starts bunnyhopping down the road when accelerating.

No signs of smoke, so i dont think its over fueling. Could it be fuel starvation from a bloked filter??

If so where is the filter and do i need to depressure the system??? Because i just covered myself in petrol to check the pipes!!

Cheers

Ian

[ketvrin]

F129RLU said:

If so where is the filter and do i need to depressure the system???

Hi Ian
Filter is just above the nearside Trailing arm inside pivot point (on an S3 anyway). I dont think you need to depressurise the system to remove that. There is a pressure connection on the fuel rail i believe that a gauge could be connected to to see if you are losing pressure in the fuel rail when things start getting warm.
Sounds like you have eliminated cold running problems (unless the cold running system is not switching off when you get warm ?? just a thought...)

K

[S3_Steve]

Hi Ian

Don't rule out the coil, I had a very similar problem with mine. Coil looked OK but was breaking down under load once egine bay warmed up. Hope you get it sorted.

[F129RLU]

Thanks for the advice, well i changed the coil last week so assuming the new part is ok i think i can rule that out.

So far

Ignition Coil,
Leads and Plugs
Air Flow meters
Throttle Pot
Fuel Filter

Still idleing fine, but just misfires and jerks about when taking power in the middle of the rev range.

Stay with me on this one, sorry for being a pain, but i just know its something simple.

Going with the cold start bits not turning off when its warm, is ther anything i couild unplug to test this theory??

Cheers

[F129RLU]

What does the pipe do between the rocker cover and the plenum?

[merky300]

Pipe between plenium and rocker cover is just a crankcase breather. I have read a couple of posts on this forum where people have experienced similar problems and it has turned out to be the fuel pump not maintaining pressure. May be worth having a search to see if you think your symptoms are similar.

Tony

[F129RLU]

Well i've just resealed the rocker breather pipe. Made no change.

So now i'm leaning towards the fuel pump. But i'm not sure. This did all start when i removed the alarm system. And that leads me to think there may be an issue with the fuel pump relay?

Well if its not sorted by the weekend, it'll be sent over to my local garage and they can have the fun with it.

Ian Moore, The Bonnet of his S2, Live at Home, Back to you.

zzzzzzzzzzzzzz!

[Jed-S]

If as you say, it kangaroos down the road then I wouldn't expect the fuel pump to be the problem. From my experience a fuel pump stopping causes a smoother loss of power than what you're experiencing. There is enough fuel in the rails under pressure to keep it fl;owing through the injectors at an ever decreasing rate until you run out. A fuel pressure reg failing might get closer but even then I'd be surprised if it kangaroos.

To me it sounds like an ignition/electrical issue. Have you checked the timing at all and is it correct for the type of ECU you have? You'll need a fault code reader (from somewhere like Halfords for a tenner) and this will allow you to place it into service mode. It may also provide you with a fault code anyway to identify the failing component. And while typing this my brain is wandering and I'm thinking that the module on the side of the dizzy has also been known to fail.

As it started after playing with the alarm.... I'm wondering if there is an additional switch installed for the +ve coil feed. A mate had a Mk1 Golf that wouldn't rev and it turned out to be a cheap low current switch under the dash that the +ve supply to the coil went through. The switch couldn't take the load and was breaking down. Which now makes me wonder, when the alarm was fitted did they use the connectors that allow you to crimp a cable into an existing cable without splitting the existing cable? If so then if that crimp has been removed could the existing cable have been damaged?

good luck
Jed

[F129RLU]

Jed, thats a good point you've made there. I did remove some of those connectors, and tape up the existing wire. Would you have any idea which colour wire will be the one taking all the power?

Does anyone else concour with this kind of electrical fault. I'm not entirly convinced(no offence jed)but i will check it all and re run the wires. Just wonder if anyone has experienced this?

This whole fault did start with the coil wiring. We may be on to something.


I'm sitting here typing, as the wife plasters the partition wall that shes just put into our flat, shaking up the gender roles here!!!! Think i may go have a bubble bath! lol

Cheers for help everyone, but keep the ideas coming, not running smooth yet!

[F129RLU]

update,

I've checked the wiring and that all looks solid. Any thin wires i have reinforced with solder. But still that same problem.

Bought a fault code reader today, and thats giving me fault 32, Air Vane Meter voltage too low. But i'm sure it cant be the actual AFM's where does the supply voltage come from?

I've had enough now, my toys are being thrown from the pram as we speak! lol

I'll send it into the garage when i can next afford it, back to sharing the jeep with the misus!

Cheers for all the help everyone.


Ian

[sphs2]

ring me on 07870 573116. simon