1.9 Gti Engine Problems

[GTIJIM 10]

Hi all

finally finished putting my engine bay together with all the correct pipes in the correct places but the engines still having problems

the problems are :

 

1. it wont idle properly

2. its running very rich (you can smell the petrol in the exhaust fumes very strongly)

3. its misfiring almost running on 2 cylinders on low RPM(under 1500) but when you rev it it sounds as sweet as a nut and fires on all 4

 

its had a service including plugs, HT leads, air filter, oil and filter and as said before all the pipes are in the right places and aren't damaged in any way and im pretty sure the timing's right

its just annoying me now as i have tried to get it running right for ages but had no success

any ideas will be much appreciated

Jim

[Paul_13 212 1 Cars]

Ht leads firing in the right order?

 

SAD doesn't sound like it's plumbed/wired right, I know you said it is

[GTIJIM 10]

Ht leads firing in the right order?

 

SAD doesn't sound like it's plumbed/wired right, I know you said it is

 

im pretty sure the ht leads are in the right firing order though will have to double check

 

i've got the pipe from the back of the SAD going to the inlet tube that comes off the throttle body and the pipe on the front of the SAD ive got going to the bottom of the inlet plenum?

[welshpug 1,626]

doesn't matter which way round the SAD is wired or plumbed, as long as the pipes are connected to the inlet tract correctly, it's a very simple device

 

it is much easier if they are the right way though

[GTIJIM 10]

checked and the SAD is correctly pipes and wire up, also set the ignition timing and still got the same problem

been looking on you-tube and I've found a car that has a similar problem

though mines slightly worse and it wont idle and is pumping out grey/blue smoke that reakes of petrol but its basically doing the same thing, anyone got any ideas???

 

here's the smoke

[Mikey S 29 1 Cars]

have you checked the wiring to the ecu temperature sensor and the sensor itself? these can cause some pretty strange running issues and cause them to overfuel like yours is.

 

mike

[TT205 42]

Sounds like unmetered air to me

 

Check for air leaks around the plenum - not all holes are necessarily blind - check bolts from fuel rail, does your coil attach to plenum - check these bolts etc

Spray some carb cleaner around these areas see if revs rise etc

 

 

Also check pipe between plenum and AFM

 

I noticed in your project thread you said:

 

"the one on the left of the expansion bottle goes to the top of the rad and the right one goes to the bottom of the throttle body but the previous owner has bypassed it to the top of the thermostat as the fixing on the bottom of the throttle body has snapped off, doesn't really matter as its only for cold starting so shouldn't affect the running:)"

 

Have you sealed this?

Edited June 16, 2011 by TT205

[GTIJIM 10]

Sounds like unmetered air to me

 

Check for air leaks around the plenum - not all holes are necessarily blind - check bolts from fuel rail, does your coil attach to plenum - check these bolts etc

Spray some carb cleaner around these areas see if revs rise etc

 

 

Also check pipe between plenum and AFM

 

I noticed in your project thread you said:

 

"the one on the left of the expansion bottle goes to the top of the rad and the right one goes to the bottom of the throttle body but the previous owner has bypassed it to the top of the thermostat as the fixing on the bottom of the throttle body has snapped off, doesn't really matter as its only for cold starting so shouldn't affect the running:)"

 

Have you sealed this?

 

will have to check for leaks as i can hear a sort of air escaping sound from around the inlet, i think its one of the vacume pipes

i haven't sealed the throttle body as i though its just a chamber around the inside that lets warm water pump round it so shouldn't cause an air leak?

[Mikey S 29 1 Cars]

i haven't sealed the throttle body as i though its just a chamber around the inside that lets warm water pump round it so shouldn't cause an air leak?

 

leaving those two pipes to atmosphere wont cause an air leak.

[TT205 42]

i haven't sealed the throttle body as i though its just a chamber around the inside that lets warm water pump round it so shouldn't cause an air leak?

 

Agreed - I got the wrong end of the stick

 

My money is still on an air leak after the AFM

[GTIJIM 10]

Agreed - I got the wrong end of the stick

 

My money is still on an air leak after the AFM

 

will have to give it a thorough inspection

[GTIJIM 10]

hi all

quick question, under the throttle body there are 3 extensions where hoses fit on to and i know 2 of them are for the water pipes but what's the 3rd one for?? because i haven't got a pipe going to that one so would that cause an air leak??

here's a borrowed picture of the one i mean from another members thread (the one under his thumb)

Edited June 17, 2011 by GTIJIM

[GTIJIM 10]

anyone?

[smithy 1]

My p1.5 does not have that one, maybe you have a throttle body from a different model/newer type engine fitted???

If there are no pipes for it I would be inclined to blank it and see what happens.

[Simes 248 2 Cars]

How is your oil filler attached?

 

Is it bolted into the plenum?

 

If not is there a bolt in place as if it's missing unmetered air enters that way.

Edited June 18, 2011 by Simes

[GTIJIM 10]

My p1.5 does not have that one, maybe you have a throttle body from a different model/newer type engine fitted???

If there are no pipes for it I would be inclined to blank it and see what happens.

the engines out of a different car so i wouldn't be surprised if it was newer

will block it off and see what happens

[GTIJIM 10]

How is your oil filler attached?

 

Is it bolted into the plenum?

 

If not is there a bolt in place as if it's missing unmetered air enters that way.

 

it supposed to be bolted to the plenum but the filler pipe has been cut a bit so i doesn't reach but i have blocked the hole off with a bolt so it shouldn't be letting any air through