New Engine Not Running Correct

[nikolashewitt]

Iv put a new vts engine into my mk1 vts. i have used the original wiring loom and exhaust and just changed the block.

the car won't idle by itself. i have to giv it abit of throttle but it sounds terrible and lumpy. if i let go of the throttle th car will cut out.

i have unplugged the crankshaft sensor and it wouldn't start at all, so i plugged it back in and it starts but sounds bad and then cuts out. i am currently using the crankshaft sensor that came with the new engine and not my original one. if it makes any difference at all? they do seem different though. the new one is just black plastic whereas my original from the old engine is metal and has a different connection.
there is fuel getting to the rail and all the vacuum pipes are conncted.

Can anybody give me any light on where the problem could lie.

[frankie]

timing?

[nikolashewitt]

the timing is perfect, tried doing it about 4 times and everytime its been the same. somebody tell me if iv done it wrong. iv locked the two cam sprockets off, and then rotated the flywheel until the mark on the lower pulley is pointing down and then i locked the flywheel with an allen key. i then put the belt on lining the marks on the belt to the little notches on the cams and then the lines on the belt and lower pulley and then tensioned.

[williamsvts]

use all your original sensors. what year is the new and old engines? sensors may be different, are they both vts or 1 gti?

[nikolashewitt]

both are vts. one is mk1 the other is late mk1 i think. as the crankshaft sensor is a black plastic bit with a small connector clicking straight into it. whereas my old crankshaft sensor is a metal bracket with a brown lead and a big brown connector block.

[gd16]

If you can narrow down exactly when the problem occurs - that'll help.

Does it drive fine/pull ok etc, just idle is crap?
Is it when it's hot, or cold, or doesn't matter?


ICV would be my first guess, but depends when it isn't running properly as above.

[nikolashewitt]

i havnt even attempted to drive it. it wont start without giving it some throttle. and if my foot isnt down on the throttle pedal it will cut out instantly. but if i keep revving it it will stay on but sounds terrible and lumpy.

[gd16]

Fuel pump/ fuel filter/ blocked injectors?

I'd change the injectors over to the ones you were using before, see if that cures it. Then check the spark plugs, or change them.

Compression ok on the engine?

[gd16]

Forgot to add - check that there are no loose/split vacuum pipes coming off of the inlet manifold.

[nikolashewitt]

the inlet manifold is fine. triple checked them. the fuel filter is new. fuel pump has always worked spot. i thought about the injectors being blocked. but they are the original ones, but the fuel rail isnt the original. could something be in the rail?

[nikolashewitt]

the engine management light doesnt come on either so doubtful its a sensor? tried swapping crankshaft sensors but still exactly as before.

[nikolashewitt]

i have also put new plugs in. sorry for all the posts but i dont know how to edit my previous one!

[chunker]

wot about injectors or temp sensor

[nikolashewitt]

temp sensor is all in okay. i am using my original injectors, but i had to buy a new fuel rail as i snapped the connector pipe for the fuel feed. could the actual rail be at fault or be blocked? whats the best way to tell?