S50 swap problems

[Fernflex]

I have a friend who installed an s50 on a 318is 1991, the engine was working fine before installing on the e30.

The problem is the engine works better with the flowmeter backwards, it still has a small rough idle but after 1,000 - 1,500 rpm it opens decently. If you install the flowmeter how it goes the idle very gets rough and end up shutting down.

We have try 2 different flowmeter and it does the same. We have check the wiring harness from the flowmeter to the ecu and it looks good everything.

Some additional info:

The car has no air filter or intake tube.
The car could have bad gas, after been parked for a year.

But it doesnt make sense that it works better the wrong way.

[e30shmobberr]

1. put better gas in.
2. clean afm.
3. try again

[328ijunkie]

Vac leak. /thread

[josuemarine]

Vac leak. /thread

Any sugestions to test this..?

[matthugie]

Any sugestions to test this..?

Smoke test is the best way, but I would start with changing the gas. Since it's been sitting for so long it needs to be changed anyway and may help with further diagnostics.

[samiam3356]

Smoke test is the best way,

haha yes, makes me laugh a little whenever I see this recommendation after seeing Jlevie say it for years.

[walktheboard]

haha yes, makes me laugh a little whenever I see this recommendation after seeing Jlevie say it for years.

[Fernflex]

I think it maybe a vac promblem because I remember the afpr was loosing pressure.

[wastedincome]

I've always just checked for vac leaks with starting fluid as I always for get my smoke tester in my other jeans