BMW Turbo Discussion  - BMW 745i and BMW Turbo Project Forums
User Name:
Password:
Save Password
Forgot your Password?
Home | Active Topics (0) | Members | Online Users | Statistics | File Library | Search | Avatar Legend
 All Forums
 The e23 745i and Turbocharged BMW Motor Topics
 BMW M106/M102/M30 Turbo Topics
 Ok...need a bit of assistance!
Next Page
 New Topic |  Reply to Topic |  Bookmark Topic |  Printer Friendly
Author Previous Topic Topic Next Topic
Page: of 3

Funfer
Grease Monkey

Status: offline


56 Posts

Posted - Aug 29 2008 :  22:24:50  Show Profile  Reply with Quote
Just go this 85 in the driveway. There are many issues to deal with, but first is the stunbling.hesitation with the motor. It has a huge miss...read more....

I have adjusted the valves to 0.012 stone cold motor, fixed a leaking fuel hose, cleaned the distributor cap and rotor (horrible!!!!!), cleaned the plugs (NGK, not bad).

It runs much better though I still have issues. It has a problem under load. What I mean, as after it warms up is hesitates a bunch while coming up through the RPM range. Keep in mind it is warm so the injectors are at the minimum open time. (does this motor have a cold start valve?) Anyway if I press ever so slightly on the throttle it seems to climb much smoother than when going to full throttle quickly. There is an occasional lumpy idle as well, not attributable to the inherent nature of the M30/M106 when warm. Definite miss. The following things I am thinking:

1) Flywheel sensors are oiled

2) AFM adjustment (it is new)

3) Fuel Pressure Regulator

4) Fuel pump/s

5) Cleaning the throttle body(should have done this already!)

6) Ensure of proper Vacuum routing. (there is a diagram on the 745i site but is for the mod.)

BTW, I am also hearing, from time to time, a loud knocking noice coming from under the battery or somewhere around there while motor is off and ignition is on. Pretty loud! What is it?

Thanks for your help and guidance!!!

srfsteve
Gas-fueled God

Status: offline


653 Posts

Posted - Aug 30 2008 :  02:56:37  Show Profile  Send srfsteve a Yahoo! Message  Reply with Quote
Put your hand on the cruise control actuator (its near the battery, and cable from it goes to throttle body) see if that is making the loud knocking. If so, probably the CC control module in drivers side rocker pannel below speaker got wet/... disconnect, fix the water leak, if you get get another CC unit consider mounting under the dash instead of rocker pannel.

For the miss, am inferring you have a stock 85' 745? Anyway, my short list rough order of attack:

1) Check motor mounts and tranny mounts. engine may be rocking under load and pressing against/ pinching strectching some hose or cable or connection, or cause leaks. ie at ex manifold. i.e. have somebody rev it while you watch the engine move.

2) check for old hoses and leaks in vac. system air intake bellows, and hoses connecting to it. and routing. Replace if suspicious. check the check valve in vac line btwn engine intake vac port and the aux vac pump / HVAC to see whether it is reversed. if so, leaks in the HVAC system will allow air to leak into the engine intake. Or just clamp that off that hose temporarily if suspicious.

3) Check TPS resistances and also same for the temp sensor for the motronic.

4) Check voltage at battery, and voltage drops in ignition and control system. Check /clean the grounds also.

5) Don't know whether just cleaning the dist cap and rotor will reveal hairline cracks / carbon tracking. If their it will not resolve them i think. Consider replacing them to be sure. Also, how sure are uo about the spark plug wires?

good luck. let us know how it goes.
Go To Top Of Page

Hit Man X
Over 745 Posts!

Status: offline


1681 Posts

Posted - Aug 30 2008 :  09:31:01  Show Profile  Send Hit Man X an AOL message  Send Hit Man X an ICQ Message  Click to see Hit Man X's MSN Messenger address  Send Hit Man X a Yahoo! Message  Reply with Quote
Get a vac/boost gauge installed. Then you can see what's going on.

REPLACE that cap/rotor/plug/wires. Cleaning them is a waste of time.

You need to verify all vac lines are installed correctly also. My best guess every piece of rubber under there is old and cracked thus making for vac leaks. http://745i.scottiesharpe.com/Welcometo745i_com_files/Turbo/T1a.jpg

Read this thread - http://bmwturbos.scottiesharpe.com/topic.asp?TOPIC_ID=5060 Basically start at the top and go through it. If not, you're simply taking blind stabs in the dark and making no progress. Also spend the money for a Wideband, narrowband Oxygen sensors aren't worth your time.



Yes, this isn't a simple car to rehab mechanically when beat down. You'll have MANY weeks of downtime awaiting parts and times of swearing/hair pulling on top of hours of wrenching.

Once it runs, you'll be rewarded with a fantastic machine.

This is my sig...

Four 745i! One '83 and three '85...I am a glutton for punishment.
Go To Top Of Page

scottie
System Administrator

Status: offline


3845 Posts

Posted - Aug 30 2008 :  17:57:28   View scottie's Photo Gallery  Show Profile  Visit scottie's Homepage  Send scottie an AOL message  Reply with Quote
If cap and rotor looked bad, just replace them.

Test wires with meter, or swap in a known good set.

Spark plugs can look good, and be bad. Even new ones can be defective.

Scottie Sharpe
San Jose CA
Discussion Board SYSOP


88 Dinan M5
1968 2002


FOLLOW ME ON FACEBOOK
My Profile
Go To Top Of Page

Funfer
Grease Monkey

Status: offline


56 Posts

Posted - Aug 30 2008 :  20:38:34  Show Profile  Reply with Quote
First, I'd like to express my gratitude for the responsed for the members who have lent their experiences and intuition for helping. Very valuable!

Ok, afer about 6 hours of intimicy with the project car today, I have the following to report...

Drive train mounts are good. Fuel pumps are good. Replaced almost all of the vacuum hoses including the air recirc hoses for the idle stab, and slide valve. Even replaced the vacuum hose going to the knock sensor computer under the dash. Temp sensors(all three) are all new, TPs does not seem to be an issue. (I dont know how you can check the voltages on the TPS with it still plugged up...by procedure) Battery has been fully charged. Cleaned the flywheel sensors, and the crank position sensor at the harmonic balancer. Will replace the cap and rotor once they arrive. All grounds are good and tight.

It runs much better! But...I still have the intermittent miss. It idles fine then it will start missing then revert back to good normal idle...kind of an oscilating effect. The AFM seems to be a key here as if I back it off of tight stop (all the way clockwise) it runs much better. If I turn it just 1/2 turn counterclockwise it misses more frequently and I have to go back to about 1/8 turn from origin. I'm pretty certain that there are no vacuum leaks and that the vacuum line routing is correct. Just uncertain about the knock sensor control unit.

So, I guess the main issue now given the above information is that it goes through periods of missing ....good idle....missing....good idle. Under load (50% or more pedal) it still misses. If I give it light, even, steady throttle it is fine and will accelerate into boost.

Any further guidance would certainly be appreciated!

BTW, Does anyone have a rear diff mount they would like to sell me? How about an AC Compressor?

Most Appreciatively,
John
Go To Top Of Page

Hit Man X
Over 745 Posts!

Status: offline


1681 Posts

Posted - Aug 31 2008 :  12:06:22  Show Profile  Send Hit Man X an AOL message  Send Hit Man X an ICQ Message  Click to see Hit Man X's MSN Messenger address  Send Hit Man X a Yahoo! Message  Reply with Quote
Buy a vac/boost gauge and a wideband, until then playing with the AFM is a waste of time and you wont know if you have vac leaks. These tools are INVALUABLE to dialing in this car.

Look up PLX or AEM for a WBO2. I don't care for the Innovate as you have to reset it and calibrate it often.



Did you have your injectors cleaned? If not, you need to as I can assure you they're dirty.

This is my sig...

Four 745i! One '83 and three '85...I am a glutton for punishment.
Go To Top Of Page

Funfer
Grease Monkey

Status: offline


56 Posts

Posted - Sep 01 2008 :  20:22:39  Show Profile  Reply with Quote
Second owner said that injectors were new. I would settle for cleaned. In any event, they are not new. I'll pick up a set of 24lb on ebay and go from there. I did manage to get the care running pretty well. I readjusted the valves again with better results this time. I also instyalled a new set of Sparks just for kicks and by ear edjusted the AFM. I know it still is not running right as it doesn't tap into all the power but it does not miss or oscilate any longer.

I'm unsure about about the mode for the multimeter, ohms or volts and the value I should be looking for but I need to dial it in for optimal engine gain.

For those of you in the southwest, I am in Arizona. I am in extreme southeast Arizona in the Sierra Vista Area.

By the way, Does anyone have a set of window switches? The PO installed a set of lighted switches that stay on all the time...meaning around the clock! Would like to eliminate the battery draw that is unnecessary...unless you all have information of a way of hooking these up so that they go out when the lights are off.

Anyone have a vacuum diagram of the HVAC system?

Once again...you all rock! John
Go To Top Of Page

Hit Man X
Over 745 Posts!

Status: offline


1681 Posts

Posted - Sep 02 2008 :  14:13:37  Show Profile  Send Hit Man X an AOL message  Send Hit Man X an ICQ Message  Click to see Hit Man X's MSN Messenger address  Send Hit Man X a Yahoo! Message  Reply with Quote
Which car did you get? The blue one with the velour interior?



Dismiss PO claims, they're usually bogus unless you have documentation to back. And unless you want to purchase another Motronic, clean the ones you have. They're near 30lb/hr AND low impedance. The 24s you're looking at are high imp and will not work. Heed the warning or you'll pay for it later. Volvo turbo injectors will work here.

Did you install W8DC or BP5ES plugs? If not, you get to remove them again. Platinum and/or resistor plugs are no good.

You can't dial in the motor until you do what I have told you. Buy a boost/vac gauge first. If you have vac leaks (which it sounds like) those must be eliminated before proceeding, if not you have unmetered air coming in and boost going out. A narrow band O2 will vary too much (even new!) for an exact dial in of the AFM. There's no reason not to use a Wideband to tune vehicles today

Good friend of mine lives in SV, works for the Feds out there.

Look under the e-brake handle for some added wiring. This is probably why the switches are always lit. Fix this ASAP or you could encounter an issue like me where the power draw is over the rating for the wiring resulting in a melted harness.

You have failed vac pods (internal rubber diaphragm ruptured) which cause the air volume to go all over the defroster. The single throw ones can be rebuilt easily, the double throws work better when just replaced. Few hundred will fix this all. Use a MityVac to confirm what pods are bad, but if you're in there I'd just fix/replace them all. See below for a guy that sells the diaphragms. Very reasonable



Trying to cheap out or going around something will just turn a mole hill into a mountain of issues. Please don't, you have to start with the basics.



Here you go

George Murphy
Performance Analysis Co.
969 Oak Ridge Turnpike, Suite 258
Oak Ridge, TN 37830

865-482-9175 9 am to 5 pm ET M-F

This is my sig...

Four 745i! One '83 and three '85...I am a glutton for punishment.
Go To Top Of Page

Funfer
Grease Monkey

Status: offline


56 Posts

Posted - Sep 02 2008 :  16:41:26  Show Profile  Reply with Quote
Yep, it was the one on Ebay...arcticblau with the redone blue interior.

Today, I hooked the vacuum gage to the motor and it is pulling a steady 11 lbs. of vacuum at idle. All vacuum leaks have been taken care of...as I can tell. The vacuum for the interior HVAC servos runs off the vacuum pump only right? The PO had a 'T' fitting in it going to the intake as well. It didn't make any sense so I just removed it and installed a new vacuum hose. Still doesn't work though. I will have to make another 'T' into the boost line and route it into the interior so I can get an idea of what boost I am currently running at 5000 rpm. Should be close.

Yep, I will have to get a wideband O2 sensor to get it right. Since this is the 4 wire type, I will need to know which two I will need to check and the values I should be looking for. Right now it has a near purrrrfect idle and response...especially after I loosened the AFM a bit.

There is one thing I wish though is hearing the Turbo....I wish it was a bit louder!

On the HVAC vacuum issue, I know there are not any vacuum leaks there either. the pump comes on and after about 45 seconds goes off. It does have some bleed off but it takes a good long while till the pump comes back on to vacuum the system again. This is good news as the reservior is intact and holding vacuum. Do you have an idea of how much vacuum it is supposed to pull? It is a new pump though.

Thanks for the help George! BTW, If you live in Sierra Vista, chances are really good to be working for the Fed Govt. Go Dawgs!!! John

Go To Top Of Page

Hit Man X
Over 745 Posts!

Status: offline


1681 Posts

Posted - Sep 02 2008 :  17:18:01  Show Profile  Send Hit Man X an AOL message  Send Hit Man X an ICQ Message  Click to see Hit Man X's MSN Messenger address  Send Hit Man X a Yahoo! Message  Reply with Quote
quote:
Originally posted by Funfer

Yep, it was the one on Ebay...arcticblau with the redone blue interior.

Today, I hooked the vacuum gage to the motor and it is pulling a steady 11 lbs. of vacuum at idle. All vacuum leaks have been taken care of...as I can tell. The vacuum for the interior HVAC servos runs off the vacuum pump only right? The PO had a 'T' fitting in it going to the intake as well. It didn't make any sense so I just removed it and installed a new vacuum hose. Still doesn't work though. I will have to make another 'T' into the boost line and route it into the interior so I can get an idea of what boost I am currently running at 5000 rpm. Should be close.

Yep, I will have to get a wideband O2 sensor to get it right. Since this is the 4 wire type, I will need to know which two I will need to check and the values I should be looking for. Right now it has a near purrrrfect idle and response...especially after I loosened the AFM a bit.

There is one thing I wish though is hearing the Turbo....I wish it was a bit louder!

On the HVAC vacuum issue, I know there are not any vacuum leaks there either. the pump comes on and after about 45 seconds goes off. It does have some bleed off but it takes a good long while till the pump comes back on to vacuum the system again. This is good news as the reservior is intact and holding vacuum. Do you have an idea of how much vacuum it is supposed to pull? It is a new pump though.

Thanks for the help George! BTW, If you live in Sierra Vista, chances are really good to be working for the Fed Govt. Go Dawgs!!! John







Ah okay, that seemed like a good solid car for the money. I was trying to get my pal into it hahaha

11" is way low, 17-19" is what you should look for... hot idle, in park/neutral. Idle is supposed to be 800 +/- 50rpm.

Block off the HVAC system on the intake manifold to put it out of the equation and see how your vac is at idle. Yes, that pump on the driver side is for HVAC only. I think like a supplement pump. No clue on what it is to hold/pull... that's low low on my list now. I know there's a lil plastic T fitting in there that fails often.

From memory narrowbands with four wires are two ground, one switched, one signal.

KKK is just not loud for some reason (a few of my MB's have KKK units), plus the AFM subdues sound also. Dave on here makes a great replacement turbocharger. ~60mm inducer on the compressor vs ~48mm stock. HUGE difference in volume for power and should make some sound. Also a higher flow exhaust will make more sound and flow better at high RPM.

This is my sig...

Four 745i! One '83 and three '85...I am a glutton for punishment.
Go To Top Of Page

scottie
System Administrator

Status: offline


3845 Posts

Posted - Sep 03 2008 :  09:24:44   View scottie's Photo Gallery  Show Profile  Visit scottie's Homepage  Send scottie an AOL message  Reply with Quote
I would agree with what has been written: Use stock spark plugs and stock injectors only.

You do have a vacuum leak if you are pulling 11" at idle. There is a hose that feeds vaccum to the HVAC system from the manifold. T'd into this is the vacuum pump. The vacuum pump should ONLY operate when there is INSUFFICIENT vaccuum in the system, like when you are ascending the Alps in northern Italy under boost and you have to change HVAC programs two or three times. IN other words, it should never turn on. If it does, you likely have a leak somewhere.

The window switch lights are supposed to turn on only when the ignition is on, OR when the drivers door is open. THere is a relay under the dash driver's side which ties into the lamp switch that powers up the window circuits. Check this first before you rip into your window switches.

Scottie Sharpe
San Jose CA
Discussion Board SYSOP


88 Dinan M5
1968 2002


FOLLOW ME ON FACEBOOK
My Profile
Go To Top Of Page
Page: of 3 Previous Topic Topic Next Topic  
 New Topic |  Reply to Topic |  Bookmark Topic |  Printer Friendly
Next Page
Jump To:

Please consider donating to help keep BMW Turbos! online.
Donate now using the link below. Thank you for helping keep the M102/M106 discussion forum alive!

BMW Turbo Discussion - BMW 745i and BMW Turbo Project Forums © Scottie Sharpe Go To Top Of Page
BMW TURBOS! generated this page in 0.7 secs. Snitz Forums 2000