my 20v again

[samg60 0]

Just a couple of questions for you 20v boys, just come off the phoen with Vince from Stealth and he is too busy to take my car at the moment which is fair enough,

I am not too bothered about the car overboosting, however it has started occasionally just stalling then not being able to restart for 5 mins,

this has either been from cold or when hot, with no particular pattern.

car is now running fine with no black smoke etc, however it does hunt at idle, these are all small problems but would like them sorted.

Vince has suggested the fuel pump relay which is possible so will take it off my relay from my old g60 golf

[samg60 0]

Got the car on the ramps today (first time I have been able to have a thourouggh look at the underneath, all looks mint) however I couldn't find a lambda sensor anywhere on the exhaust which means the DTA must have been mapped with just the MAP sensor, would it make good sense to get a lambda probe inserted and then remapped, could this also be the problem with the hunting idle and the occasional stalling at junctions, everything else is fine on the car but just need these simple thinsg sorted. any ideas anyone.

 

 

Also the fuel tank seem sto be creating a vacum so its obviously not able to get any air (hissing noise when cap is opened), does anyone know how to fix this, I tried a search on the forum and it seems some peopel have had this problem and fixed it but couldnt find out how ?

 

Thanks Again

[CoxyLaad 0]

the dta system doesnt like lambdas I am afraid. I had the same thoughts as you, tried to set it up on a rolling road, and it ran like a bag of sh't. binned one lambda.

 

curing overboosting is quite simple Sam, you can do it yourself if you had a laptop. Basically you have 2 tables, one for fueling one for ignition. Both as used to select a base value for either the spark advance or the injector pulse width. Then in adition to this you have a set of modifying tables that the ecu applies to the selected base value. eg the boost manifold air pressure table is linked to the map sensor (obviously) and applies a percentage multplication dependant on the boost in the manifold. So to cut a long story short once you have the base map and the correction factors in for boost which you already have, then it basically maps itself and you can play around to a certain extent with the boost.

 

Which leads me onto the boost table. This is a simple table which displays an RPM scale and an associated maximum boost pressure. So all you need to do is wind the values on that boost pressure table back a touch and you will have your desired effect.

 

either that or go and part with a fortune for someone else to do it ;)

[samg60 0]

Thanks Matey, yeah already had a look at the tables, will get another laptop sorted out and take a look, Vince was very helpful running through a few of the DTA tables anyhow.

[samg60 0]

car sorted looks like the problem was the vacum in the fuel tank, have since loosed cap until I can clean the breather and hunting for idle and stalling has stopped.

[CoxyLaad 0]

wow, thats a new one to me.

I have had loads of cars that generate vaccuum in the tank, you get a chshhh noise when you take the cap off. Its never caused any problems to me, in fact it happens on all my fuel injected cars I have had. I thought it was normal.

[samg60 0]

Yeah thats what I thought, maybe its pure coincedence, but I think it was putting the fuel pump under a bit of strain as the fuel pump would stop and not start again occasionally, I guess we will see,

but drove it over the weekend and havent had a problem at all no stalling or hunting for idle so fingers crossed

[mk2_20vt 0]

Is the vent pipe that used to go to the carbon can blocked off?. Its the middle pipe between the 2 fuel lines in the engine bay.

[samg60 0]

looks like the vacum in the tank was a red herring, as it stalled again, getting a little lost here as it always seems to be when coming to a junction on a slope, approackinh downwards not upwards, the car has half a tank of fuel so it cant be that and tehn afterwards the idle bounces, sometimes when it happens it can take a few mins to restart, is it possible its the fuel pump (i have already replaced the fuel pump relay) do g60s have a main control relay similar to mk3 golfs which can cause a problem like this ?

 

Its not a huge issue, but I want to get it sorted and am running out of ideas, i would have initially said its perhaps the map, but i ran it all weekend and it was fine.

 

the only other thought is teh blue temp sensor that was knackered on my car, and replaced it with a slightly different part number as the part had been superceded its now rated at 140max rather than 125, but like I said the problem wouldnt be itermittant would it ?

[CoxyLaad 0]

only problem you will have with the temp sender is that it may think the engine is too cold and and put more fuel in, or weirdly, if the map is setup properly, too hot and also add more fuel.

I doubt that would be the problem, you would get rich running throughout.

 

It sounds like its not got enough air entering it with the closed throttle to maintain an idle. Remember when you are slowing up the revs are falling which will cause a considerable vaccum in the manifold and therefore starve the engine. I suspect this is why you had a dodgey valve in the back of the manifold...

 

I ran my 20v without an idle valve and it was fine, I think you just have to play with the ignition timing on the closed throttle cell settings as it approaches idle speed. Ideally you need to be advancing the timing slightly as it approaches 1100rpm slow it doesnt stop the engine speed falling, but slows it somewhat.

 

Oh the joys of custom management :D

[samg60 0]

I have a feeling that all my problems are related to a dodgy earth somewhere, started my car last night and it started and idled fine, as soon as I switched the lights on it stalled and you could here the fuel pump slow.

Its very noticable that when I have the car at idle any large power consumption i.e. electric windows, lights etc will cause the car to start hunting for idle. haven't had a chance to check whether the alternator is supplying enough charg as yet or whether there is just a short somewhere, but am convinced its the problem.

[CoxyLaad 0]

stick at it. You will get a flutuation in idle when you put the lights on if you have no idle stabilization system. Mind you I never had problems with my idle

[samg60 0]

sorry to keep bringing this back but am a little stumped, I have tested the alterantor and the battery when the car is running and they are very healthy, however when the car is at idle and you turn the lights on (got my wife to do this whilst I had the boot open to hear the pump) and you can here the pump slow as the load increases, it isnt a slight dip and then back to normal it actively slows (well the noise does anyway).

 

When driving in the night it will stall at idle even though I have increased the idle to just over a 1000rpm , where as in the day the car performs almost flawlessley (does stall occasionally.)

 

If this really is the engine managament then I am happy to take the car for a remap and get the idle parameters adjusted however it just seems strange.

 

As stated before I have checked the alternator with lights on load and it sees a healthy 13.76 V (also used a bosch alternator and Battery tester and it says they are fine)

 

Any Help greatly appreciated.

 

Sam

[CoxyLaad 0]

I personally think you are looking for a problem that doesnt exist sam.

[samg60 0]

I Wish I was mate, but definatley spomething not right just not sure what it is, increased the ilde to about 1200rpm this morning (there is a screw on the throttlebody which prevent the throttle hitting the stop, this can be adjusted) and still it stalled and bounced on idle, doesnt seem to make a difference where the revs are when idling.) and as soon as I hit the lights it just wont go.

 

the car has been much worse since i but the old 52 amp battery back in, I borrowed a 62 amp for a few days. but both the battreies are new Bosch silver.

 

I guess I will just have to take the car to vince