1.4 petrol poor idle issues

A

Azim

Member
I have a 1.4 petrol A2.
The original engine was replaced by the previous owner due to cambelt failure .
This engine fitted was a 1.4 with individual coil packs .
It runs very rough on dile, but when rev'd seems to run smoother leading me to believe the issue was with the spark plugs .
I have since replaced all the spark plugs for new ones .
The engine still runs rough on idle .
I removed the individual coil packs and given them a good clean .
Ive checked between pin 1 and 4 and have similar resistance figures .
Is there anything else I should be doing or looking at to help deteemine what is causing the erattic idle and poor starting ..

Thank you in advance ...Azim ò
 
what state are the throttle body and EGR in? Any possibility that there is air getting in (ie requirement for new oil cap on top of engine etc. ?) .
For that matter, how about the pre-catalyst lambda?

I replaced all of these as well as plugs, cables, coil pack (AUA) (but I believe you have covered these parts above so looking at the other things I replaced in substantially reducing these issues).

As stated above, have a look at engine error codes, clear them in case there are any legacy / spurious ones due to low voltage, and see which ones come back.

What's the economy like?
 
I have just given the individual coil packs a good clean and reassembled them .
making sure the outer shrould is fully seated to allow the coil pack to make connection with the spark plugs .
Waiting for the rain to allow me to re install them .
Will then inform you of my results.
 
Robin_Cox said:
what state are the throttle body and EGR in? Any possibility that there is air getting in (ie requirement for new oil cap on top of engine etc. ?) .
For that matter, how about the pre-catalyst lambda?

I replaced all of these as well as plugs, cables, coi9l pack (AUA) (but I believe you have covered these parts above so looking at the other things I replaced in substantially reducing these issues).

As stated above, have a look at engine error codes, clear them in case there are any legacy / spurious ones due to low voltage, and see which ones come back.

What's the economy like?I will due
Click to expand...

Axit said:
Give it a compression test.

Good Luck.
Click to expand...
I hope the compression is fine as the replacement engine was one with full service history .
I will check compression in due course if I have no luck .
 
My 1.4 2003, got a sudden misfire, done all the coil packs, replaced the injector, which I`ve now found out is shut down by the ECU after 400 misfires, that was an expensive mistake.
The compression test showed low on one cylinder, now having the cylinder head refurbished with replacement valves, guesstamate being £1000-£1500, I hope yours is not as serious as mine.
Apparently the valve guides are made from a brass material which is prone to wear, leading to valve problems.
 
Axit said:
My 1.4 2003, got a sudden misfire, done all the coil packs, replaced the injector, which I`ve now found out is shut down by the ECU after 400 misfires, that was an expensive mistake.
The compression test showed low on one cylinder, now having the cylinder head refurbished with replacement valves, guesstamate being £1000-£1500, I hope yours is not as serious as mine.
Apparently the valve guides are made from a brass material which is prone to wear, leading to valve problems.
Click to expand...
Thank You for your input .
I have done a scan with my vcd.
I have found only two faults .
1 miss fire on cylinder 4
2 Fault 01206-
Signal for the duration of ignition time .(implausable signal ).
The missfire has dissapeared after I cleared the faults .
But fault 2 has just shown up .
 
OK. So if my understanding is correct, could it be that the car at the moment doesn't currently know where in the rotation cycle the engine is from the perspective of sparks and injector firings?

If this was the case then you'd be looking at things like the crankshaft position sensor (hall sensor?) or knock sensors? ; when the former goes wrong the ECU is still able to work the timing points out to acceptable levels second-hand from another sensor but takes a couple more cranks to work it out. Could also still therefore be a bit iffy if it is using some kind of backup method to determine timing but other things also need cleaning as well?


edited; looked up 1206 on Rosstech. Perhaps another direction to look at if not a complete red herring. Wasn't there another post recently where engine lights came on and misfiring with the Climatronic unit turning itself onto full cold?

01206 - Signal for Duration of Ignition Off Time​

Possible Causes​

  • Ignition Switch faulty
  • Wiring between Instrument Cluster (J285) and Climatronic Control (J255) faulty
  • Instrument Cluster (J285) faulty
  • Climatronic Control (J255) faulty

Possible Solutions​

  • Check Ignition Switch
  • Check Wiring between Instrument Cluster (J285) and Climatronic Control (J255)
  • Check Instrument Cluster (J285)
  • Check Climatronic Control (J255)

Special Notes​

  • If this fault won't clear with key on, engine off, try clearing it while the engine is running.
 
Thank you for the reply .
The car was initially running al be it a bit lumpy like it was in 3 cylinders .
I changed the spark plugs and cleaned and refitted the coil packs .
Now it refuses to start .
Does anybody have drawings of position of timing marks so I can at least check if everything is in the right position .
 
Azim said:
Thank you for the reply .
The car was initially running al be it a bit lumpy like it was in 3 cylinders .
I changed the spark plugs and cleaned and refitted the coil packs .
Now it refuses to start .
Does anybody have drawings of position of timing marks so I can at least check if everything is in the right position .
Click to expand...
Check if the rev counter is showing a few hundred rpm, or, not moving at all, when the engine is cranking. If no movement, crankshaft sensor is likely the problem.
Mac.
 
If you have VCDS, better check the camshaft sensor via Measuring Blocks, as that is the sensor output to the ECU, whereas the rev counter is driven by the instrument cluster, so could be a cluster fault. I suspect that's why Ross-Tech mention the cluster in their hints. A cluster fault will effect, (by "corrupting" it), the ECU.
As a general rule, Measuring Blocks, (from the ECU), are preferred, as everything displayed on the cluster is driven by the cluster electronics, not directly by the ECU.
Mac.
 
I think I need help from a more experienced person
My experience with vcd's limited
Is there anybody who can diagnose the issue local to coventry .
 
Hi,
I've read this post twice and Robin_Cox has put forwards valid lines of fault investigation which I personally would follow.

I would only add, as I can't see it in your thread, do you have a new battery?

Battery voltage @
Ignition off =
Ignition on =
Engine running =

You may only require a new battery and have a vac leak.
Almost forgot to say, good luck 🙂
 
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The battery is in good condition and does crank for a good while .
I shall check the voltage and will report back
How ever the car does not start .
 
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Hi

Have a look at the scan register, there maybe someone near to you who may be able to help

Free Scan Register

This is a register of members who generously offer free scans for other members. To arrange a free scan: 1. Click the pdf map in the footer and choose a location. 2. Cross reference the location number in the table below to identify the member. 3. Click on their username on the left, click...
www.a2oc.net www.a2oc.net

So if I have understood correctly we have gone from lumpy idle to not wanting to start at all. I would go back to basics and remove one of the spark plugs, plug it back into the coil pack, rest it on the top of the engine and crank the engine. Do you see a spark? You could do this for all spark plugs to check you are seeing a spark at each.

As to timing marks, the crank sensor will be telling the ECU what the relative position of the crank is to control when each cylinder will fire. I think that 01206 is an HVAC error code so would be surprised if it was pertinent to non starting

Report back if you see a spark

J

​

 
@Azim
How long have you had the car?
Has it had rough idle since you got it, or did it start, and idle, perfectly when you first got it?
Anyone,
Is the ECU for the early 1.4 engine, single coil pack, the same as the later engine, individual coil packs?
Mac.
Edit : Just wondering if the ECU should have been/was, changed when the engine was changed from AUA to BBY.
I'd think they were different, as the AUA sparks two plugs at a time, not just one.
Maybe check the date code on the ECU, that would show if it's original, I think ...
Mac.
 
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