Seriously terrible running 635

[Masterdoofus]

ok....
car is a 87 635csi

to start.i had looked all over on the forums and read about rough idle and printed threads out to check on stuff.

ive just had the head compleatly rebuit at my local speed shop (i had it off to do a blown head gasket job) and it idles badly and runs worse. at all rpm ranges it gasps wheezes shudders and shakes.. very unbecoming of a 6.

checked the timing twice so far and it looks like its ok

all cylinders have around 145-150psi compression. and spark plugs are blacker than before the head was done. and car was running ok before

ive looked all over for vacume leaks and used carb cleaner with no real effect. and when i remove the oil filler cap on the valve cover its hard to belive but it actually runs worse.

its idles around 750 which is alright but it sound terrile and the car shakes with riyhim. there probbaly is a misfire. and the cap and rotor were changed before the head job.

ive heard about changeing the AFM ratio/mixture where is the ajustment screw for this?

idle control valve looks ok to me and its all pluged in correctly(attacted to the butterfly valve)

ARRG ive spent days and im gonna miss my anual bmw club meet beacuse of this.

thanks,
Mike

[Bob Balbirnie]

Is it possible you have a bad plug wire or two? In the process of removing them and replacing them on the head job it is possible one or more was damaged. (or unlikely with the numbered wire sets even placed back in the wrong position)

It is most likely something simple vs complicated...

Good luck with it, Bob

[M635]

I don't if this might be the problem... Maybe you got some crap in your fuel tank, that's stuck in that fuel filter pump thing. I removed mine with my new 635, cleaned it up and put it back in, and now everytime I give it, it doesn't feel crappy, and goes. But I'm really not too sure, it never affected my idle, just performance.

[Masterdoofus]

we checked the plug wires and they are in the right place we also checked with a timing light and they are firing. and i dont think its fuel related, i changed the filter a few months ago but i did sit for a month. i hope its simple but my brain is to complicated to figure it out.

[woods]

Black plugs usually means you're running rich or you have a bad misfire. Are all of the plugs black - or just a couple of them? Does the car throw any codes? (Does an 87 even throw codes? )

I would double check that all of the various sensors are connected back up properly and clean the contacts with some CRC electronics cleaner while you're at it...

Keep us posted.

[CrazyCanuck]

Originally Posted by Masterdoofus ive looked all over for vacume leaks and used carb cleaner with no real effect. and when i remove the oil filler cap on the valve cover its hard to belive but it actually runs worse. ARRG ive spent days and im gonna miss my anual bmw club meet beacuse of this. thanks, Mike

Removing the 710 cap causes a vacum leak....therefor it runs worse.

How does the drive? Have you only idled the car?

[Masterdoofus]

it runs worse than it idles.. lol
im thinking of changing the plugs tommorow or somthing to see.. someone also said look at my valve cover so i need to check that. aside from a new gasket what should i use as a quick test on the valve cover?

[Al Canuck]

Sounds like an FPR gone bad. Do a fuel pressure test. Bet she's over fueling like crazy.

Al

[carter]

And M30 love Silver plugs... don't use others.

[E30M20B25]

If you need another FPR I think I may actually have one. What is the 6.. 3 bar?

I should look that up myself ^_^

Feel free to call again whenever Mike.

[Not Registered]

I second the fuel problem suspicion. Check fuel pressure, and if that checks out, make sure all your injectors tick.

[sigwiig]

i had something similar happen to my girl recently. it turned out to corroded connections on my ECU... check your connections?

my car was cutting out a little once in a while then suddenly went really rough on idle and was cutting out when i was trying to excellerate.. it would in let me rev in neutral, but wasn't giving me any power in gear.. then it would cut in again. out.. dangerous. the check engine light would come up sometimes.

i had to bring it to two places (don't ask, long story, but Nixon is in BBY and the car was running like a POS, so i brought it to a place i used to go to) after exhaustive searching and thinking i was going to be looking at trying a new ECU they pulled it out (behind the glovebox) and noticed some corrosion on the points so they cleaned it up and she runs like a charm again.

good luck,

[smithwison4]

I think so your car needs revamping of its parts.

[Masterdoofus]

replaced the FPR... no luck, im stumped.. next on the list is ECU