hello and a bit of help

[deadcat]

Hiya, Haven't been on in a while.
I fitted a new engine to the ol' coupe, so I've been sorting that.

and the help bit is:
does this sound like an inle manifold leak?
Real choppy idle, sometimes stalls, takes a while to drop to normal idle after revving, Usually drops below normal idle after revving and then bounces back up to normal idle revs.

any help appreciated.

[bstardchild]

Hiya, Haven't been on in a while.
I fitted a new engine to the ol' coupe, so I've been sorting that.

and the help bit is:
does this sound like an inle manifold leak?
Real choppy idle, sometimes stalls, takes a while to drop to normal idle after revving, Usually drops below normal idle after revving and then bounces back up to normal idle revs.

any help appreciated.

Hmmm - is it injected?

If it is.........

It could be an inlet leak but my money would be on an idle control valve problem - it'll be bypassing the throttle body intake hose to the inlet manifold other side of the butterfly and it's used to control the idle by increasing or decreasing the amount of air going (by)past the butterfly

These are often gummed up with carbon or oily residue and then are slow to respond - leading to all the symptoms you describe - removal and a good dose of carb cleaner often restores them to normal operation

If it's carb'd then it could be an intake side leak but it could be a lot of other things too.......

JM2pW

[deadcat]

Hmmm - is it injected?

If it is.........

It could be an inlet leak but my money would be on an idle control valve problem - it'll be bypassing the throttle body intake hose to the inlet manifold other side of the butterfly and it's used to control the idle by increasing or decreasing the amount of air going (by)past the butterfly

Yeh.. it's single point. I had all the ISV off before I changed the engine. and cleaned it all up..
How much are new ones?

[bstardchild]

Yeh.. it's single point. I had all the ISV off before I changed the engine. and cleaned it all up..
How much are new ones?

How did you clean it?

[deadcat]

Yeh.. it's single point. I had all the ISV off before I changed the engine. and cleaned it all up..
How much are new ones?

How did you clean it?

Sprayed the little pokey-outy thing with carb cleaner and WD-40

[deadcat]

It's definatly not the ISV, That is all working. it just seems like there is a misfire randomly on the cylinders like it's not getting enough fuel.

[Gareth_GT_Hatch]

Still not fixed then? Did you use all new gaskets and stuff like that? Did you do an ECU reset Like I suggested? Could be the blue temperature sensor...whats fuel economy like?

[deadcat]

Still not fixed then? Did you use all new gaskets and stuff like that? Did you do an ECU reset Like I suggested? Could be the blue temperature sensor...whats fuel economy like?

Yep. Used new gaskets, although I think it's a leak somewhere in the inlet. dunno why.. it's just a feeling...
I have done an ecu reset and tested the blue temp sensor, which is giving out the readings it should. The engine idles real choppy, it's like there is a misfire like a broken lead or spark plug. but intermittantly and randomly.

[tainmrk3polo]

i had an intermittent misfire on my GT. i changed the leads, dizzy cap and rotor arm and all is good apart from in the morning when it misfires like a beehatch till the temp gauge moves up to 70

[Tahrey1043]

gaz just wondering

the economy on your was bobbins in every day use with a busted sensor
did you ever see what it was like haring it down the motorway?

*still* getting better than 30mpg despite my only trips these days being heartless thrashes! but still highly suspicious of my sensors!

[Gareth_GT_Hatch]

gaz just wondering

the economy on your was bobbins in every day use with a busted sensor
did you ever see what it was like haring it down the motorway?

*still* getting better than 30mpg despite my only trips these days being heartless thrashes! but still highly suspicious of my sensors!

Well, I mentioned my lambda probe wire was snapped didnt I? Just checking. Well I got 34mpg going from manchester to St albans near london to pick up the engine and gearbox I won on ebay (the engine now belongs to deadcat incidentally) 188 miles in 3 hours aint half bad in my book, keeping it below 90 on the way there. but I should have been around 40mpg as Ive done these sorts of trips in the past (like inters and the polo show) and both those times my economys been in the mid 40s. (which is how I beacame suspicious) Even when I was just using the car for work I managed better than 35mpg so Id be a tad suspect if my economy was low. You done yourself the extra earth wire yet?

[deadcat]

Well, I mentioned my lambda probe wire was snapped didnt I? Just checking. Well I got 34mpg going from manchester to St albans near london to pick up the engine and gearbox I won on ebay (the engine now belongs to deadcat incidentally) 188 miles in 3 hours aint half bad in my book, keeping it below 90 on the way there. but I should have been around 40mpg as Ive done these sorts of trips in the past (like inters and the polo show) and both those times my economys been in the mid 40s. (which is how I beacame suspicious) Even when I was just using the car for work I managed better than 35mpg so Id be a tad suspect if my economy was low. You done yourself the extra earth wire yet?

What sensors have gone awry on yours then gaz? I have never had more than 34mpg out of mine. Could explain the totally crappy idle.

[Gareth_GT_Hatch]

Well on my light blue GT before I put the 1.4 in the blue temp sensor gave false readings when cold. (only for about a minute though so I never bothered changing it - after that it was fine) That was the only bother with that car

The black GT's original engine had seeminly every fault under the sun! I changed everything! Lambda probe, blue and black temp sendors, and finally the throttle valve potentiometer (which is what the problem was after all that). Luckily I wasnt foolish enough to buy a lambda probe new (i stole one off a 1-litre in a scrapyard. so in the end it "only" cost about £45 in the end for all the bits. The 2 temp sensors from vag came to £30! whereas the throttle valve pot was £50! bought one 2nd hand off someone in the end.

Whats it like to drive then? is it very juddery, i e when you old your foot in the same place crusing along you can feel the power coming and going? when my lambda wasnt working on my dark blue GT (the one I came round to yours in) there were no apparent running problems it just smelled rich all the time. If its judderyt I would suspect the throttle valve potentiometer (assuming single point injection cars have em - im pretty sure they do) Its either that or some new leads and plugs are in order.

[Tahrey1043]

am i lazy? does the pope s*** in the woods!

course i havent..... but i might get the jive to do it when i get the tyres sorted THIS weekend (last week turned into quotes only). Managed to kick myself into topping off the oil yesterday after the last weeks change at least.

prob is it now involves lying down in damp crap under the car in a british autumn, rather than lying on dry dust in summer. that and the underseal too.

dunno bout deadcats but mines a beaut at constant speed, its throttle response thats a particular bastard, especially at low revs. and the idle is all over the shop. it doesnt wildly fluctuate while you watch it, but its seemingly a noticably different speed every time you start it or drop to idle. and the couple times i had problems... two saturdays ago, it ended up idling at about 500rpm(!) but on all 4 cylinders, and tuesday night it was rough as anything on starting - sounded like it was running on 3 pots. that time it also sounded like it had no oil so after about 10 secs i panicked, turned it off and looked on the drive for a big ass leak... nothing... restarted it and it was immediately fine. very odd.

[deadcat]

Well on my light blue GT before I put the 1.4 in the blue temp sensor gave false readings when cold. (only for about a minute though so I never bothered changing it - after that it was fine) That was the only bother with that car

The black GT's original engine had seeminly every fault under the sun! I changed everything! Lambda probe, blue and black temp sendors, and finally the throttle valve potentiometer (which is what the problem was after all that). Luckily I wasnt foolish enough to buy a lambda probe new (i stole one off a 1-litre in a scrapyard. so in the end it "only" cost about £45 in the end for all the bits. The 2 temp sensors from vag came to £30! whereas the throttle valve pot was £50! bought one 2nd hand off someone in the end.

Whats it like to drive then? is it very juddery, i e when you old your foot in the same place crusing along you can feel the power coming and going? when my lambda wasnt working on my dark blue GT (the one I came round to yours in) there were no apparent running problems it just smelled rich all the time. If its judderyt I would suspect the throttle valve potentiometer (assuming single point injection cars have em - im pretty sure they do) Its either that or some new leads and plugs are in order.

Well the car is ok if I take the battery off everytime i stop (resetting the ecu) for a while, the idle is slightly juddery, like its slightly misfiring, then as it gets warm, the problem gets worse, when it drops below 1000 revs after a while of driving the idle shakes the whole car and it just cuts out. it's like it's not firing right at lower revs, like the distributer is not advancing or retarding the spark so it fires funnily. What controls the spark advance / retard?