Engine Idle From Start Hot Or Cold......

[josh]

Hi all,

Pretty new to all this so here goes, i have a small problem with my car...... when i first start it hot or cold it really struggles to find its self so i have to give it a little gas then it starts to settle down, (no probs when driving) however when im just about to pull off and i think its sorted it seems to keep doing it reving between 0600 (or stalls) and 1500, any ideas ive looked all over the fourm, the fuel pump has been changed along with the spark plugs, just had a MOT and flew through it so?????? only just learning about the little beast ive got ive no other ideas where to look.

Dont fancy taking it to an expensive dealer for them to rob my money,

Hope this helps and this is my little project, first engine..........

Thanks again,

Josh

[SAM_328ISE]

air flow meter, coil pack could be failing, crank sensor. ???

could be a number of things,

some of the others should be along soon and may be more help then me.

[josh]

Ok cheers is all that self done or expensive, also sorry for all the questions but is E30 my car? just loked at some pics and compared them to the thing in my boot and i think the AFM has been chhanged recently.

[SAM_328ISE]

and yes i think yours is an E30 as i used to have a 316i on a 1989 and that was E30

[josh]

Cheers, bit more meat to the bone, i took off the lead that connects to the AFM and the car sounded like it stayed the same, i was told that normally when you pull that off the car tends to stall.??

Oh and got a bit excited with the rev thing its between 600 and 1000 but constantly keeps going up and down, with that its taking longer to start when i turn the key...................

[josh]

oh and how do i know what engine i have? M10 / M20 or M40? alien speak to me :o

[SAM_328ISE]

i shall have a look into it and see if i can help in any way so will get back to you this evening.

:D

[SAM_328ISE]

Following on from the E21, the E30 was fitted with M10 straight-4 and M20 straight-6 engines. The 316 used a 1766 cc M10 fed by a carburetor and producing only 66 kW (90 PS; 89 hp), but this allowed BMW to offer a cheap, entry-level car in the range. The 318i had the same M10 engine, but with Jetronic fuel injection, pushing power to 77 kW (105 PS; 103 hp) and improving fuel economy. Finally, the 320i (2.0 L M20 with 92 kW (125 PS; 123 hp)) and 323i (2.3 L M20 with 105 kW (143 PS; 141 hp)) completed the range. Later, in 1985, a 2.5 L version of the M20 boosted the power of the top model to 125 kW (170 PS; 168 hp), replacing the old 323i. The 325ix (All Wheel Drive model) had a 2.5 liter M20 with 125 kW (170 PS; 168 hp) (same as the 325i).

just had quick look and think yours has the M20 engine

316 = m10

318 = m10

320 = m20

323 = m20

(could be wrong but thats how it seems??

[josh]

WOW what a legend thanks Sa.

Now back to main issue any1 ideas??

[SAM_328ISE]

no worries that what we here to do is help.

also i think the engine is meant to stall when AFM unplugged or the revs are meant to drop, so if your getting those symptomswhen its plugged in i would start by changing that before anything else and see what it does

:D

[Guest Mister Dabsy]

Check all the pipework and inlet manifold for air-leaks ;)

[Guest DazH]

Following on from the E21, the E30 was fitted with M10 straight-4 and M20 straight-6 engines. The 316 used a 1766 cc M10 fed by a carburetor and producing only 66 kW (90 PS; 89 hp), but this allowed BMW to offer a cheap, entry-level car in the range. The 318i had the same M10 engine, but with Jetronic fuel injection, pushing power to 77 kW (105 PS; 103 hp) and improving fuel economy. Finally, the 320i (2.0 L M20 with 92 kW (125 PS; 123 hp)) and 323i (2.3 L M20 with 105 kW (143 PS; 141 hp)) completed the range. Later, in 1985, a 2.5 L version of the M20 boosted the power of the top model to 125 kW (170 PS; 168 hp), replacing the old 323i. The 325ix (All Wheel Drive model) had a 2.5 liter M20 with 125 kW (170 PS; 168 hp) (same as the 325i).

just had quick look and think yours has the M20 engine

316 = m10

318 = m10

320 = m20

323 = m20

(could be wrong but thats how it seems??

Sam you Wiki Whore! haha

Same engine as me, M20B20. Unfortunity, it wasn't built with an Idle control valve so things get a tad complicated with idle as so many different things control it. The "B20 is prone to 'Additional Air Slide Valve' sticking (As I found out the hard way) casuing it to jump all over the gaff but more importantly, If you DO disconnect the MAF it will stall. I can confirm this as it happens to me.

It being an old Jetronic lump, the rate in which the fuel is injected heavily relys on the MAF and when no info is sent to the ECU the injectors simply stop firing therefore stalling. It should be impossible for it to fire if the MAF is disconnected...

MY idle was really unstable and I figured it was a small crack in the breather tube between the rocker cover and the throttle body (Under the intake manifold). As Dabsy said, check all your pipes.........

[josh]

Ok then will check all that on sat round a friends as hes a BM slag, and i can confirm with the AFM unplugged it drops a little but doesnt stall, think we'll just pull every thing out and off to fault find and give it a dam good service as it wa standing for a while.

Will let you all know the out come and thanks again at least this gives me a starting point.:D

[Guest Mister Dabsy]

If the MAF is failing or failed the engine will run and the ECU will adjust accordingly, hence overfuelling to keep it running - Unusually higher mpg can be the first sign of an air-leak or dirty MAF...

Good post Daz B)

[Guest DazH]

If the MAF is failing or failed the engine will run and the ECU will adjust accordingly, hence overfuelling to keep it running - Unusually higher mpg can be the first sign of an air-leak or dirty MAF...

Good post Daz B)

Elaborating on this... MY car stalls. I put it down to the Jetronic system. MY MAF appears to be okay when its plugged in. Weird.

[Guest Mister Dabsy]

Quite possible Daz... Mine is struggling at the mo so I Know the MAF and maybe TB need to come off for a clean, but with mine being an auto, putting her in Drive raises the revs to avoid a stall (not a market stall lol) ...

[SAM_328ISE]

lol :D darren, had to try help some how i sit on the forum most days thinking what i can post so i though i might aswell try and help people :rolleyes: haha

and josh let us know how you get on and what it was causing the problem. :D

[Guest Mister Dabsy]

lol :D darren, had to try help some how i sit on the forum most days thinking what i can post so i though i might aswell try and help people :rolleyes: haha

and josh let us know how you get on and what it was causing the problem. :D

Good post earlier in the Topic mate, they have to be considered ;) B)

[Guest DazH]

lol :D darren, had to try help some how i sit on the forum most days thinking what i can post so i though i might aswell try and help people :rolleyes: haha

and josh let us know how you get on and what it was causing the problem. :D

Its how I learnt stuff matey.... Keep it up! Good post

+1

[SAM_328ISE]

cheers mate! :D

[josh]

Once ive done it all i'll re-post the fault if found, whilst im here any1 know where i can get the right MAF for the car? EBAY has a lot but not sure which 1 is for me.

Cheers again all, glad i joined :lol:

[SAM_328ISE]

best way of checking mate is look at ya old one and match it to the one you think is right.

if not email the ebay seller and ask most will help.(just make sure they have good feedback and aint messed people about in the past on car parts if they have then go soomewhere else)

if all fails then go to a good car parts supplier and ask for a qoute they should be able to give you a qoute on the right part just by your number plate!

MAKE SURE YOU SHOP AROUND AND DONT JUMP INTO A CHEAP VERSION OFF EBAY!

[Guest DazH]

http://www.realoem.com/bmw/

[josh]

Cheers Daz, and for all evry1 else whos followed this, i took the air filter out followed by th AFM then the rubber pipes (is that the throttle body) which go into the cylinder........... i found oil in all these parts and the connecters even on the air filter, so wiped them through and now the car sits at 1000 revs and doesnt change as much (just a little), would i be right in thinking it wants to be about 800?

Not to forget giving it another clean along with sparkplugs, leads and pretty much anything that can be undone so will let you know after ive done that.

Might be in my head but it feels smoother driving haha

[Guest Mister Dabsy]

Another Crime Solved eh?