Misfire like symptoms after changing inlet manifold?!

[Cuzza12345]

After experiencing idle problems with a 1.1 inlet on my VTR engine i changed over to a 1.6 inlet manifold.

(1.1 idle problem thread; http://www.saxperience.com/forum/showthread.php?t=417649)

The car is now running like it has a slight misfire and its lost some power, the exhaust tone has changed to a deeper tone under acceleration. I do have a slight blowing in my exhaust but it didn't effect the performance with the 1.1 inlet on so i didn't expect it to now?.. The idle also sets itself about 1500rpm and clutch down rolling to a junction it drops to nearly cutting out about 500revs then bounces back up.

The lad i bought the 1.6 inlet off said it was running fine on a VTR he was braking so i trust it to have no issues but this has left me confused, any suggestions or solutions to the problem?

Driving me mad now! :wall:

[Heftydanielson]

You've probably fked the sensor by cleaning it.

Also you say about the vacuum pipe in the post linked, when mine broke it idled like a pile of shite but it's a auto adjusting idle so it could take a little while to adjust to the new running conditions.

[Cuzza12345]

I didn't clean it i swapped them over, and the vacuum pipe is for the brake servo and doesn't affect the idle.

The auto choke runs off of the ICV (idle control valve) and usually poor idle is a result of that but im sure i have a fine working ICV hmmmm

[Gareth_R]

Air leak would cause a high idle

[Monkgti]

was the gasket or rubber rings ok when you put it on? get some carb cleaner and spray it all around where the manifold bolts to the engine and see if its drawing air around it, if it is you'll hear the engine rev up or die down

[mcjacko1987]

most probs air leak. start it up and put your hand over the throttle body. if you dont feel it suck you will have an air leak somewhere

[Cuzza12345]

After checking over for air leaks i found there was none although when driving the car is starting to lose spark and the exhaust tone is changing, gonna check over the plugs and clean them up this weekend. Give the injectors a clean up too!

[Heftydanielson]

"but im sure i have a fine working ICV"

Check it, might as well dude.

[Sinque]

Sounds very similar to my problems... Idle all over, nearly cutting out when dropping the clutch at junctions, exhaust tone etc.

I've cleaned the icv, new lambda, new map sensor, new oil, new air filter, new oil filter, new spark plugs, battery off for an hour to reset ecu. Still the same... Must it be the coil pack?

[Cuzza12345]

Someone get steve in here to lend advise! haha