racer86

You can see them a little better in these pics...

18 hours ago, NickVyse said:

are they 7" cromadora cd66 replicas? That's a lot of rubber and very little offset you've squeezed under standard arches, looks mean as hell. Love it.

 

Thanks for the love.  They certainly are.  A LOT of arch work and alignment required to get them under and maintain the stock body; worth it though, I love how it sits, but it also drives well too with all the stuff under it set up for it.  

18 hours ago, Lorin said:

^ Beautiful car ! 
 

You RHD guys get it easy with the velocity stacks !  I know you pay for it on the other side though…

Ha ha, thanks!  Yeah, deleting the brake boosters was a golden ticket too in that respect! 

This summer has seen me really finish up my 2002 and get it where I want it - my "period correct cafe racer", so thought I'd indulge and share some pictures by @jamiebuftonphotography done for the BMW Car magazine feature (engine bay shot is one of mine @racereightysix) 

Massive thanks to 2002FAQ for the constant help and being an invaluable resource and community, couldn't have done it without you! 

Rob. 

Morning All, hope you're well and staying safe.

Firstly, I wanted to thank you all for your help, advice, suggestions and moral support during this miserable issue! YOU ARE LEGENDS! 

I got the manifold back from the machine shop yesterday and put it together last night: New BMW gaskets and a dab of sealant for good measure: 

Now I've not driven it, but I can confirm having started it and ran it up this morning IT RUNS PERFECTLY!!!!!  I've changed a few things like the timing, points gap, brake booster hoses, posh BMW gaskets and the machining etc. but ultimately I think IT WAS A VACUUM LEAK as expected and it was just a case of hunting it down.  

I can't wait to get it back on the road now and have a blast!  Thanks again all. I am OVER THE MOON! 

Hi Sam, 

I have the exact same issues. 

I removed my intake and exhaust and found no physical obstruction. It's a mystery. Hopefully my manifold comes back on Monday so I can put it back together and try some more stuff. 

If it runs with more air, maybe it's over- rich. I'm going to try BP5 plugs so they run hotter and I can run richer. 

I have a 4 branch ex manifold and it has been suggested it my be causing scavenging on 3-4 thouh I'm not convinced as I'm on a stock cam...but if you're not could be a factor?

1 minute ago, Hans said:

Is #1 plug wire over the rotor tip?

Yes, sure is.

Thanks all. 

While I wait for the manifold to come back I've been going back through the basics on the ignition timing and marking the crank pulley with white paint ready for when I can get the timing light on it:

I found the following: 

1. The points has slipped to 0.025" so I reset to 0.0016" (FACEPALM)

2. When I set the timing static to 3 degs BTDC I had to rotate the dizzy anticlockwise a fair amount! you can see the line where is was marked on the shaft/ clamp....

The method I used was timing the to the 3Deg BTDC mark on the crank pulley and then rotated the dizzy so the line on the body aligned to the line on the rotor arm - sound right? 

Vac chamber position looks more "right" to the Haynes manual too...

Ps. is the "ball bearing" on my crank pulley 25deg BTDC?  I could only find a TDC mark on the flywheel. (Note: this is a carb '73 2002). While line on the outside is TDC. Inside pulley is TDC and 3deg BTDC (I believe) 

I've also cleaned up the gasket faces on the head ready to re-fit the manifold:  Pics of it cleaned up.  I've gone for geniune BMW gaskets leaving nothing to chance!  Pricey! 

Thanks, Rob. 

17 hours ago, sam1904 said:

OK, 90% better!

Plugged the booster line which helped 10%. The real help was the vacuum line to the bottom of the fuel bypass. As you know that fitting has a 90 degree radius and my line was just a little too large. Replaced with a different hose and added new hose clamps. 

Seems to be MUCH better now

 

Hi Sam, have you got a picture of the fuel bypass? 

19 hours ago, Deilke53 said:

First off: nice car!

 

I believe it has to be spark.  I know you checked 100 times, but you have one of the pics labeled  "order in image is 4-3-2-1"  just for fun reach down and swap the 3-4 plug wires so its the same firing order listed on the valve cover..cant make it run any worse.    No?  check your points gap at all 4 positions and check for slop in your dist shaft.

 

otherwise:

Did you do the comp test again after it was running badly?  Dead adjacent cylinders would make me suspect a  head gasket leak between them. Shouldn't be a problem that could hide from a simple comp test, but it is a problem that can hide at high rpm.   You can do a crude leak test by pulling those 2 plugs and have a buddy put compressed air to each of those cylinders at valves closed tdc.  See if you can detect any leakage next door.  *use the hose from your comp tester and duct tape cobble something together that will make your buddy's task easier.

 

-Hard to believe could be a single downdraft carb  issue that only shows itself on 3-4. 

-you've proven there's no booster hose leak.  BTW you're not driving it until you figure it out so just keep that intake booster port plugged for now just to be 1000% sure.

-Any other intake leak can usually be easily detected with careful targeted application of your favorite non-chlorinated flammable aerosol while the motor is running before going to the machine shop.

 

Hi Deilke, thanks for the feedback and suggestions. 

I'll check the leads again when it's back together; like you say it's hard to believe it's going to be on the carb side.  Once the carb is back on, new gaskets and machined manifold I'll see how it runs and spray some more brak cleaner around.  Then I'll do the timing...after that....I'll do another comp test (the values stated earlier were ones from when it's been running badly)...

If none of that cures it...might be time to pull the head. WELP. 

On 4/11/2020 at 12:54 PM, scatman75 said:

Get us a closer pic here, i zoomed in and i think i can see a defect on 3 but its hard to say. I know you said they are new gaskets but the latest video is symptomatic of a vacuum leak. The trouble with vacuum leaks is that everything can appear to be fine but a doubled up gasket or a hairline crack will cause issues

Pics below, though I've not cleaned the mating face since taking the manifold back off...

Hi all,

Just to let you know I've not given up on this yet, but also not solved it...for the last 3 weeks the inlet manifold has been at the machine shop....which got locked down due to Covid19.....so who know's when it's coming back!  All on hold, but will report back as soon as I have some progress! 

The good new is I now have access to a variable advance timing light...so something else to check when it's running. 

Hi Sam, 

Sounds like you're having a very similar issues to me...bad news is I've still not got to the bottom of it:

I did my compression test cold, throttles wide open until it reached peak....

Hopefully one of us gets to the bottom of it! 

5 minutes ago, kbmb02 said:

Q: Are the paper gaskets present between the intake manifold and the cylinder head? One ‘combo’ gasket between water divider and #1 cylinder, then individual gaskets at #2, 3 and 4. -KB

Yes, all 4 gaskets are present and new...

38 minutes ago, '76mintgrün'02 said:

 

I am not sure what you mean by two boosters, but there should be a check valve between the intake runner and the brake booster.

 

I get teased for recommending the Innova 5568 timing light so much, but it is a very useful tool (essential, IMO) and relatively affordable... get it before that changes.  Setting timing based on what it was really isn't very practical.  You've made a lot of changes since then.  The variable light will let you see what the timing curve is throughout the range.  I guess people who don't appreciate variable lights simply have never used one.

 

I don't want to be insulting, but you do have the firing order based on the clockwise rotation of the distributor, right?

 

The black coil needs a ballast resistor inline, as it came from the factory.  The early cars have a ceramic block style, with a coiled resistance wire on the back side and the later cars, with the coil mounted up forward have a resistance wire inside the wiring loom.  If you have a tester, you can see what the resistance is on your coil and add an appropriate resistor to bring that number up to 3 ohms.

 

This stuff really doesn't answer the 1&2 / 3&4 discrepancy, but is important.

 

Did you set your float height for the plastic ones?  I think that is around 35 mm, as opposed to the brass ones that get set around 40 mm.

 

Thanks for all the nice photos.  

 

Tom

Tom, thanks for your help and I really appreciate going through the basics...it's got to be something simple! 

Firing order: Yes, I can confirm clockwise rotation of the rotor arm and leads in the right order based on this. 

Timing:  I'll get it on a light when the manifold is back on to check where it's at.  

Coil:  The coil comes with a 3 Ohm primary so possible doesn't need a ballast? 

Float height:  It's a plastic float I've set to 34mm.  Factory is 35 and, apparently, in racing applications you should run 33mm....I went in the middle as fuel was a concern...but apparently not the issue. 

Picture attached of better times....when I could drive it and hadn't spent a fortune making it worse  ha ha ! 

Pursuing the vacuum leak theory I blocked off the take off from the manifold for the booster and started spring brake cleaner around (at this point had it burst into flames I'd have let it burn - frustration levels are HIGH!)  You can see spraying it at 3&4 lifted the idle and, not in the vid, but 1&2 didn't....

HURRAH, I'VE FOUND THE ISSUE......NOPE! 

I reassembled with sensibly copious amount of Loctite posh instant gasket, allowed to cure over night, fired it up and NO DIFFERENCE GIVEN THE SAME TEST.Maybe it was pulling it into the air filter? 

I've stripped it off and the image shows No.4 on a marble slab (kitchen shopping board, don't tell my wife) which is the straightest edge I have. Doesn't look look anything gaskets, bolts and sealer wouldn't solve. 

I'ave taken the manifold off again and have sent it to the machine shop to get it perfect.  I have new genuine BMW gaskets too.  

I fully expect this will make no difference. 

For reference, pug image is after 15-20 mins running to warm up and then drive up and down the road, some foot down, come cruise up to about 50mph.  Order in the image is 4-3-2-1. 

Hi All, thanks for the helpful and quick responses...typing all this through and sharing is a big help, never mind all the useful feedback! 

Sorry, I should have said before, the car ran and drove really well with the original Solex PDSI and standard exhaust for the few hundred miles I drove it before tearing it to bits.  I will say the carb was going off though, but it didn't bother me as I knew it was coming off. 

Ray: I wanted this to be the answer.....I blanked off the vacuum port on the inlet manifold completely (with a grommet/ some tape and my hand to make sure I had a good seal) and no difference.  I have now replaced all the vacuum hoses anyway. 

'76mintgrün'02: There is NO check valve....just a 3-way connector to the 2 boosters and then up to the manifold. Is this missing?  It did not have one fitted before? 

Timing I have not checked however I have not altered it since it was set up when I bought it and it was running/ driving well.  There are marks on the distributor which are still lined up.  I have tried rotating the dizzy to advance/ retard and no difference.  That said I don't know where the timing is at...I just know it ran well! 

Firing Order: Yes, I'm sure...i checked and checked and checked until I was going mad...I timed the engine up to TDC and matched the rotor arm to 1 (at about 10pm, bulkhead side as you stand at the front of the car), then 3-4-2 

Coil: Yes, the black one is the original Bosch one. I replaced it with another Bosch coil (the aluminum/ blue one shown) part 0221119027 which was listed for the 2002. There is NO ballasted resistor and wasn't previously. 

Valves:  I thought they sounded loose, but they are @ 0.007"....they were tight before...maybe I shoot for 0.006" this time.

Thanks again all!