Help please?!?! Car won't start after airbox mod...

[sierra055]

Well, after I finished patting myself on the back from a job well done following modifying the airbox and running the hose down, I started the car to move it.
The idle sat at around 1200rpm then with a blip of throttle, rose up, then settled at around 2000rpm after slowly dropping back down.
I thought I might have left something unplugged or fowling the throttle cable, so I turned off the car and went to check.

After confirming that all was clear and plugged in, I went to start the car again only to find that it doesn't want to start!! Basically it just cranks and cranks but refuses to turn over.

Any thoughts please???

FWIW, I did the airbox mod last night but ran out of time to run the hose. I put everything back and drove it for probably 50k's last night with no problems. Only difference today is the silicone hose running from the lower passenger side vent to the airbox.

[sierra055]

Crisis over...

Well.... I think the new air intake scared the crap out of the ECU...
Looks like the ECU got a bucket load more air than it expected, so it over fuelled and just flooded itself.

Gave it 30 minutes and removed the top of the airbox to give it more air to compensate for the fuel, and after dumping a bit out of the pipes it cranked over. After about 5 minutes of idling high, it dropped back to about 1000rpm then back to it's normal 700rpm and all seems to be well again!

[99gti]

Thank god for that! I was a bit worried there for a moment. I didn't notice mine do that but I also fitted my TIP at the same time.

Glad to hear it all went well!

[ope126]

Well.... I think the new air intake scared the crap out of the ECU...
Looks like the ECU got a bucket load more air than it expected, so it over fuelled and just flooded itself.

Gave it 30 minutes and removed the top of the airbox to give it more air to compensate for the fuel, and after dumping a bit out of the pipes it cranked over. After about 5 minutes of idling high, it dropped back to about 1000rpm then back to it's normal 700rpm and all seems to be well again!

700rpm seems quite low!
Mine idles at 840rpm via Vagcom! (which I thought was high, but have now been told that it is within the OEM specs of 780 - 880rpm)

Is 700rpm with A/C (climatronic) on?

[NGOLF.U]

700rpm seems quite low!
Mine idles at 840rpm via Vagcom! (which I thought was high, but have now been told that it is within the OEM specs of 780 - 880rpm)

Is 700rpm with A/C (climatronic) on?

mines is around there too...probably a lil higher...

[sierra055]

Yeah, it's there or thereabouts.
Going to hook up VAGCOM next weekend and have a look.

Ran the car again last night and it's great. Girlfriend drove the car this morning and she hardly got down the road before calling me asking what i'd done. So it must have had SOME improvement for her to notice it.