Engine Runs Well 1St Drive, Next Drive Is Awful!...

[Ivelostmypants 2 1 Cars]

Ok this may be blatently obvious to most of you (but not me!) But basically my car runs fine the first time i get in it, for whatever distance, revs are good and doesnt feel like it wants to die. Yet if i stop, start up again then the 2nd drive is terrible, it wants to cut out, is twitchy and pulling away seems like an effort as it's not smooth at all!

Any ideas what i need to check here?

The car definately has a character! so much so that it plays up nearly every time i'm in Bristol! - maybe it was abused and ragged there in its past and has trouble dealing with it haha.

[Simes 248 2 Cars]

Hello

 

Could you be a little more specific.

 

When you mean second drive is this after a long rest period before the first.

 

Does it always follow this formula?

 

It wants to cut out etc is this below certain or above certain revs?

[Ivelostmypants 2 1 Cars]

It can be instant, pop into a shop then once you drive off again, it just starts to suffer. Once the revs drop below 1000 it wants to cut out so need the accelerator to hold some revs in it. So mainly at traffic lights etc.

[mhyphenl 10 1 Cars]

It can be instant, pop into a shop then once you drive off again, it just starts to suffer. Once the revs drop below 1000 it wants to cut out so need the accelerator to hold some revs in it. So mainly at traffic lights etc.

 

I'm having the exact same problem, generally always when it's fairly warm. Leave it long enough and it's classed as a first drive again I guess. I drove about 20 miles yesterday no problems, stopped at a shop, got back in and started ok but lumpy idle at lower revs than before, drive off reluctantly compared to before and stalls when I come to the next junction, it's almost like a sensor has become unplugged. I actually set my revs to around 1050 tickover while it's behaving to avoid the stalling when they decide to drop!?

Also it occasionally has low revs on a very cold start which pulsate up and down and has a similar hesitant feel when pulling off, it corrects after a few seconds!

 

The other day I pulled off the tube from the inlet manifold to the pressure regulator in desparation and nothing changed still ran like sh8t with unusually low revs, could it be this??

[Ivelostmypants 2 1 Cars]

 

I'm having the exact same problem, generally always when it's fairly warm. Leave it long enough and it's classed as a first drive again I guess. I drove about 20 miles yesterday no problems, stopped at a shop, got back in and started ok but lumpy idle at lower revs than before, drive off reluctantly compared to before and stalls when I come to the next junction, it's almost like a sensor has become unplugged. I actually set my revs to around 1050 tickover while it's behaving to avoid the stalling when they decide to drop!?

Also it occasionally has low revs on a very cold start which pulsate up and down and has a similar hesitant feel when pulling off, it corrects after a few seconds!

 

The other day I pulled off the tube from the inlet manifold to the pressure regulator in desparation and nothing changed still ran like sh8t with unusually low revs, could it be this??

 

Yup that sounds about exactly the same as mine, and about the same idle that I'm running to to compensate for the cold start and lumpy second drive! So do you reckon to change the regulator then? As that's something I can give a try. Just picked up a gas tester and want to sort out my air fuel ratio, but the engine is setup as best as it can be for this problem esp idling wise etc, when adjusted differently in the past the revs would fall in seconds and cut out, whereas now it'll flutter under 1000 before dying, giving me some time to compensate with the accelerator. So ideally I'd like to sort this problem first before adjusting the mixture!

[PhilNW 43]

Have you tried the ECU temp sensor or SAD?

[mhyphenl 10 1 Cars]

Tried the SAD, mine takes a while to close judging by the time it takes for revs to drop when cold. Could be temp sender but more awkward than the pressure reg so will try that first! I could do with a gas analyser when I have this sorted, where did you get yours? My engine light is on most of the time unless I accelerate and the fault is always just mixture! Please let me know how you go and I'll do the same!

[Ivelostmypants 2 1 Cars]

Well I've tried to locate the SAD but have so far failed! Is there an alternative location for it? or is it mega tricky to get to? As I was bent over the engine in all angles, but can only see a block sticking out under the dizzy that shows in the pictures. Also found that the vacuum advance had its hose connected to it, but the other end wasn't connected to anything, so would this be a player in my problem? Where does it connect too? In my search I also found the 2 small connectors red and green close to the dizzy round the back of the engine, had the green one not connected! So that's back on, but the vacuum pipe still off.

 

For the gas tester a mate has lent me it for a few days before I have to give it back sadly else I'd have been willing to post it to you for a bit. I'm guessing gastesters all work the same? this is a Gunson that sits at 2.0% in the air, and when inserted and settled the reading was 1.8% at a decent idle. Is there a specific number I should be hitting? It was a quick test today, and once the SAD is checked etc then I'll have more of a play with it with some revs to see what else it can pick up.

[Ivelostmypants 2 1 Cars]

Tried the SAD, mine takes a while to close judging by the time it takes for revs to drop when cold. Could be temp sender but more awkward than the pressure reg so will try that first! I could do with a gas analyser when I have this sorted, where did you get yours? My engine light is on most of the time unless I accelerate and the fault is always just mixture! Please let me know how you go and I'll do the same!

Found that my vacuum advance pipe was off at the throttle body end, pipe had split bad. It just fits on now with no splits after it was trimmed up. I have a 200 mile drive today so I'm sure that'll be enough distance to see how she responds!

So in all I had a sensor clip off and that pipe, hopefully they make a difference....will let you know! - may be worth checking your vacuum advance though, as looking at other threads it links to rubbish idles.

[welshpug 1,651]

It wont help that your dizzy is on upside down the vac pipe not being on will introduce an air leak though quite small given the bore of the port, it wont affect the running to the extent you describe though, worth checking the vac unit is working and not seized or leaking air through the diaphragm.

 

SAD should be bolted to the housing pictured with the blue sender (which is the CTS)

 

Ideal CO levels are around 1.5%.

[Ivelostmypants 2 1 Cars]

It wont help that your dizzy is on upside down the vac pipe not being on will introduce an air leak though quite small given the bore of the port, it wont affect the running to the extent you describe though, worth checking the vac unit is working and not seized or leaking air through the diaphragm.

 

SAD should be bolted to the housing pictured with the blue sender (which is the CTS)

 

Ideal CO levels are around 1.5%.

Haha I'd never even noticed the dizzy being upside down! It's been like that since buying the thing :\ and I had nothing to compare to, so glad I posted that pic and you spotted! Didn't have much time to fiddle with the car today, I turned the dizzy round but then wouldn't fire, and was in a rush to get home from a long trip, so didn't have time to google the ht lead order and timing corrections. So I had to slap it back on upside down! Replaced the vacuum hose too. The car ran fantastic on the return journey! The second drive shortly after getting back was ok too, sounded like it was unsure where to idle at first when started up, and like it could die, but once driven any stops at junctions still held a good idle and decent engine purr. HOWEVER, I noticed lots of gunk in the tubes and AFM meter today, wiped it away, for it to quickly return later on when checked. I also had to top up the coolant this morning as that had dropped a lot! Needless to say the car will be getting a compression test tomorrow and a decent inspection! Looks like overall a LOT of things are all chipping in to make the car run so weird! Cheers for your help so far guys!

[Ivelostmypants 2 1 Cars]

Ok, have been told by one mechanic to get a compression test done to test for the head gasket, and been told by another not to. Hmmm....

[Anthony 1,002]

I turned the dizzy round but then wouldn't fire, and was in a rush to get home from a long trip, so didn't have time to google the ht lead order and timing corrections. So I had to slap it back on upside down!

I take it that you didn't mark its position before removing it? The position that the dizzy is bolted up at is very important, as that sets the base ignition timing and a few degrees either way is the difference between it being down on power and unresponsive from it being over-retarded, to risking engine damage from it being over-advanced.

 

Reason that it wouldn't start with the dizzy flipped over is that the HT leads would then effectively be in the wrong order meaning that the ignition timing would be 180 degres out.

[Ivelostmypants 2 1 Cars]

I take it that you didn't mark its position before removing it? The position that the dizzy is bolted up at is very important, as that sets the base ignition timing and a few degrees either way is the difference between it being down on power and unresponsive from it being over-retarded, to risking engine damage from it being over-advanced.Reason that it wouldn't start with the dizzy flipped over is that the HT leads would then effectively be in the wrong order meaning that the ignition timing would be 180 degres out.

The dizzy had marks to align the top, but where I've flipped it over I had to guess as to where it roughly sat. Obviously I must have got it wrong, as the engine now runs better. Also hinting at me of why this car has felt more sluggish than my previous gti. I'm now struggling to find any garages to adjust the timing correctly for me, or at the least not until next week! Haines manual says about tachometer and stroboscopic light, is there any more manual way to sort it until that time, trial and error etc, or if the engine is running smoothly at the moment best to just leave it until it can get properly looked at?

[TT205 42]

With no tools (bar a spanner)

If it's currently running ok and not pinking - mark the dizzy position, advance a tad, drive round the block, advance a tad drive round the block - continue until it pinks under load, then retard a tad - et voila

Edited March 20, 2013 by TT205

[Ivelostmypants 2 1 Cars]

With no tools (bar a spanner)

If it's currently running ok and not pinking - mark the dizzy position, advance a tad, drive round the block, advance a tad drive round the block - continue until it pinks under load, then retard a tad - et voila

Cheers! Will try that tomorrow morn and and see how I get on!

Also on the point of poor running I've come across the major bodge job I was left with by some cheap mechanic! (You get what you pay for for sure!!) Basically I needed some welding done before my mot, and in the process the guy spotted an oil leak, then told me when he took the pipe off it cracked, he told me had sorted it, and It passed the mot, and the car had been run a bit since, (filter only A few months old) - When he said he had fixed the problem I now see that the pipe is gone and my oil filter is fitted straight onto the engine! Just how dodgy is this and what problems will it give me? Also what's the correct name for the pipe for me to now source!?

[welshpug 1,651]

its not dodgy but I would question how much of an animal he was to break those parts.

 

All he has done is remove the takeoff and pipes that supplied the remote oil filter housing which is still present in the back of the picture, you would need the takeoff that bolts to the block, probably the bolt and the pipes, I'm guessing your garage just binned them, they are unlikely to be available new any more so second hand it will have to be.

[MikeC 10]

Did some Gti's come with a remote Oil filter?

Or is it just the fitting for the oil cooler.