rho

7 hours ago, 2002Scoob said:

Sounds pretty good from here! 

 

FWIW, I've found that DCOE's can be rather finicky regarding idle speed, and need to properly warm-up to temp to maintain a consistent idle. 

 

I have my idle set to around 900-ish when warmed up, but depending on ambient temperature that means on a cold day and a cold start, it's like 400, maybe 500 rpm and will flat stall if I'm not feathering it the first few minutes, or 6-7 on a moderate, normal day. 

 

Also, holy mirror-array, Batman! 

So true on the idle, my car will sometimes idle so low it will stall in the morning... once it’s way hot then it idles around 1K depending on the current weather conditions. Although I’m still trying to solve the issue with slow rpm dropping from time to time ( it’s scary cause it actually accelerates when in 1st gear when it does this ) not too safe.

Those are WINK mirrors from year past... great for never having a blind spot.  When I change lanes I never have to turn my head

7 hours ago, Dudeland said:

Seems to be pulling nicely. 

 

Thx...  I had a full tank of gas plus slight uphill from first to second gear ..  Next time I’ll find a flat section with a 1/4 tank

After dealing with the exploding exhaust issue and trying to get the new DCOE 45's to idle within reason (still not there yet, sometimes it idles over 1K and other times under, probably linkage issues) I finally was comfortable enough to put the 02 thru an acceleration test run.

Hope to get this idle hunting issue resolved sooner than later but at least I can drive her hard now :)

Next project is to install a AFR system to dial in the carbs...

15 hours ago, roadhog0 said:

I like 2.5-3.5. I ran into this with my carbs. At 1.5 there is darn nero zero fuel. You can really see it if you have a wideband. Also makes drive ability horrible with the screws in a bunch. I have tuned the idle jets accordingly because of this.

Thanks for this tip, especially since you monitored it with a wideband AFR meter. I'll start with 3 and work my way from there.

What idle jets are/were you running when you did this?

On 2/8/2020 at 1:05 PM, TobyB said:

One real problem with an HEI is doing what I've circled below-

 

the wires should cross at right angles, not be tied together in parallel.

The zip- tie is a particular no- no.

 

Especially if the wires had loose ends, or poor connection, that'll totally cross- fire ya.

 

t

 

I followed your suggestion and made custom wires using MSD 8.5mm.  Thx for the tip!

After resolving my exhaust explosions issues, due to timing and possible ignition wires incorrectly bundled together (Thx FORUM!) I made custom wires using MSD 8.5 wires.  Car seems to run happier although that could just be speculation.  I've never been able to 'chirp' the rear tires in 3rd gear and now I can, so new carbs, wires, timing adjustment has put me closer to dialing this thing in.  Now I just have to tackle the erratic idling issue and I'll be closer to Nirvana...

 

After installing my new 152G's the tech from Redline said to turn the idle mixture screw 1 1/4 turns out from lightly seated on all 4 screws to start.

Well after reading a bunch of info on the same subject below are 4 instructions for the same process.  2 sites say the older DCOEs have different needle shapes so 1 turn is good while the new versions have a skinnier needle and 2-3 turns out is where to start.  Why would the tech at Redline suggest 1 1/4?  He knew I just purchased new carbs... (rhetorical)

Anyway, what have most ppl started with for the newer 152G's?   I'm leaning toward 2-3 turns out, which is unfortunate since I already spent a ton of time tinkering with other settings after initially setting them 1 1/4 out per Redline :(

Below are the instructions from 4 different sites...  BTW, the Datsun site probably had the best Weber DCOE info I've ever come across on web.  I've learned more on that one site the all others combined.
 

TopEnd Performance
DCOE Series and IDF / IDA. On a DCOE or multiple DCOE's you should be between 3/4 turn and 1.5 turns out for all older model DCOE's (DCOE 2, 9, 18, etc.)
 and 2 1/4 to 3 turns out for late style DCOES (151 and 152 with air bleed screws under the white caps.)

RedlineWeber
Standard DCOE Settings:
Speed screw ¼ to ½ turn in after contact with lever maximum.
Mixture Screw 1 turn out from lightly seated.

Datsun Tech page
http://240260280.com/Tech/Carbs/Weber/DCOE Theory Operation and Tuning.html
Early DCOE screws had a wide tapered end that flowed more mixture with just slight movements (turns). Weber later changed DCOE's to a more precise screw with a very narrow taper.  The result is that early DCOE screws flowed adequate enrichment at ~ 1 turn out from full stop.
Later narrow tapered screws flowed the same amount at ~2.5 turns. Current production DCOE151's have the newer, narrower tapered screws.

Piercemanifold Tech support
...said 1 1/4 turns out from lightly seated.

On 2/9/2020 at 10:32 AM, Preyupy said:

It looks to me like those are wasted spark coils, 1 coil fires cyls 1 & 4 and the other fires cyls 2 & 3.  This also means you have a spark happening with the exhaust valve open on the exhaust stroke.  If you are pumping the throttle and dumping a lot of fuel into the engine and into the exhaust you can get an ignition event to happen with the valve open and it is going to also burn the fuel in the exhaust. 

That makes perfect sense, thanks.

Update:  I cut the existing plug wires and rerouted them correctly.  Changed the spark plugs and when I removed the old ones I was shocked that I had resistor plugs installed, that has been corrected.  Timing was advanced ~8 degrees.  Upon attempting to start the car it fired up after one push of the gas and about 2 seconds of running the starter, so that was a HUGE improvement and relief.  After restarting the car when warm it fired up instantaneously, like a modern fuel injected car.  Much faster than it has ever done.

Thanks everyone for all the suggestions that solved, for now, the explosion issues!

7 hours ago, TobyB said:

One real problem with an HEI is doing what I've circled below-

 

the wires should cross at right angles, not be tied together in parallel.

The zip- tie is a particular no- no.

 

Especially if the wires had loose ends, or poor connection, that'll totally cross- fire ya.

 

t

 

NOTED! and will re-route tomorrow.  Thx for the excellent tip

9 hours ago, Preyupy said:

Fill us in on your ignition system.  If you want help you need to give us enough information about what you have done so we stand a chance of helping you.  

 

I have never seen that ignition system before.  How does it work? does it rely on the standard distributor for advance?  is there any programmability to it?  If you are relying on a 48 year old distributor to have the same advance curve as it had when it was new you are in for a bit of a shock unless you have actually tested it.  

 

Again you need to know what the ignition advance is when you are cranking as well as how much total there is (check it at 3500-4000 rpm) If you set it at 25 deg @ 3000 rpm you are probably retarded by 8-10 deg from where it should be.  

The ignition system is similar to a MSD unit but adds a separate coil to each sparkplug.  It's magnetically triggered and is not programmable.  The dizzy does all the advancing (Bosch 008).  After reading your post that my timing could be off ~10degrees I calculated the amount I needed to rotate to advance the dizzy that amount and adjusted it as noted. 

It made me think that if it was truly retarded too much that could be why the fuel is not burning and flowing into the exhaust system, possibly the spark was happening at or around TDC or even AFTER... 

I wont be able to start the car until the new plug wires come in and after I replace the spark plugs.
 

I'm hoping this weekend the car will start with less effort and w/o the explosion my neighbors no doubt look forward to 

17 hours ago, Preyupy said:

You are obviously running some kind of electronic control for your ignition along with wasted spark coils.  What is your ignition timing at cranking speeds?  You could also have a problem with the distance of the pickup and the trigger wheel,  if the gap is too large you will get a very weak signal at low engine speeds.  Is that an optical pickup in the "distributor"?  I would also go back and check your cam timing.  After having DCOEs on my 2002 since 1975 I have the cold start process down pat and all you should need is 1 pump of the throttle and a touch of it when you crank the engine and it should fire up immediately even in sub freezing weather.  

When I initially set this up years ago I believe I set the timing at 2500 or 3000 rpm at the 25degree BB on the flywheel. (008 distributor).  From reading about timing on this site, that may have been the wrong initial timing setting...

ill check the cam timing tonight to see how far off the crank pully pointer/mark it is.

The dizzy is magnetic, see pic of the cap off...

5 hours ago, Hans said:

I solved a number of mysterious problems by dumping what looked to be healthy Accel wires. I thing the carbon breaks down. And yes, cam out of sync could be an issue. The sprocket  locating pin should be at 6pm facing crank, and if memory serves the two top bolts parallel to top of head (if you want to confirm mark on cam. Find a pic of the front of the engine.  I prefer to use chokes, others prefer pump and pray.

I just ordered MSD Race wires (50ohms a foot), so that should take that possible issue off the table.  As for the timing marks.. I'm going to take the valve cover off soon to confirm how far off they might be.  Thx for the suggestions!

11 hours ago, Dudeland said:

Depends on the length of wires.  MSD recommends 0 ohm wires. 

0 ohms?  is there such a thing...  I looked at their race wires and they spec at 50ohms per foot.

12 hours ago, '76mintgrün'02 said:

This is sort of a tangent, but you might want to consider adding an e21 exhaust manifold gasket with a built in heat shield, to protect your new wires.

 

http://www.rogerstii.com/bmw-2002-320i-318i-exhaust-manifold-gasket-heat-shield/

 

+1 good idea

I don't know if this fact may be part of the issue (hoping the new wires will resolve most of it) but when I built the engine I noticed that when the cam gear on the head was at TDC as indicated by the mark, I looked at the mark on the crankshaft pully and it was not pointing directly at the pointer, it was maybe 1cm off (can't remember which direction)...   is that a HUGE issue? I'm thinking maybe i could have been 1 tooth off at the timing chain.  Funny thing is that the car pulls to over 6K in 1st and 2nd gear and does not seem to be affected by it, maybe it is suffering and it could/should pull stronger but I'll never know unless I pull the cam gear and align it closer to the pully mark... 

14 hours ago, Hans said:

Are you using cold start valves (aka chokes) or just pumping the pedal? Are those Accel wires?

Cold starting tends to high light any minor deficiencies in the electrical system. So I'd recheck timing. What about plugs?

No Choke, I just run the starter 5 seconds max while pressing the gas 2-3 times... then repeat.

Accel Wires, very old and I just posted the ohm readings (way off for cylinder 1 and 3)

Plugs will be changed before I restart and so will the ignition wires...

More info to share!

I just checked the resistance for each wire

1 = 1.350K ohms

2 = .850K ohms

3 = 1.354K ohms

4 = .853K ohms

So I guess I know where ONE of the issues lie...  I'm guessing the car is not happy with the discrepancy between 1.3 and .8K ohms

13 hours ago, coloincaalpine said:

I believe that even MSD recommends that "High Capacity Discharge Systems" should have wire separators.

Thx for that tip, I'll separate them before I attempt to restart the car again.  

Do you know if the connector that attaches to the spark plug needs to be a certain material?  I know my old '02s had those hard plastic or ceramic housings, and my Accel wires just have a rubber boot.

Thanks for the ignition wire suggestion.  I’ll reroute them as well as check to see if  all wires are within spec.  I did not realize that if they were touching/crossed each other bad things might result. Attached is the current layout as well as the area of the headers you can see where the pipes slip together on one section.

Greetings, I have not posted for over 5 years so good to be back.

As the Subject line states, after trying to cold start the car when it does not turn over after 5 seconds on the starter and pumping the gas 2-3 times the car does not start and 50% of the time a loud (gun shot loud) bang explodes in my exhaust system.  I’m thinking a ton of fuel is passing through to the exhaust area and igniting.  This happens at cold start and rarely to never on warm start.

Could it be the timing is way off?

Air leak in the exhaust system? (which it has because my system was constructed where one section of pipe slips over the other section and no welds)

Im running dual Weber DCOE 45’s with a mechanical fuel pump (could the fuel pump be pumping too much pressure?)

Thanks for any suggestions..  I don’t want the neighbors to call the cops on me thinking I’m shooting firearms in my garage!! :)

Robert

You would think all the open cutouts might cause the oil to possibly foam up in certain driving situations.

I believe the turbo head gasket is thicker... maybe you can try that approach.

So it's safe to say my E21 CR 5 speed has the fine splines and most, if not all, E21 standard 5 speeds are fine splines as well making it possible for me to use my 4 bolt flange on a E21 standard 5 speed tranny that currently has a 3 bolt flange (since they 'should' both have fine splines).

Sorry for restating what I know you said in your reply but just want to be semi-sure before I purchase a used standard E21 5 speed tranny.

Thanks again,

Robert

Is the output shaft from a 320i CR 5 speed with a 4 bolt flange the same as a regular 320i 5 speed with a 3 bolt flange? I've been told the output shaft splines could be different (fine vs regular).

If the answer is yes or no depending on the year/model of the tranny, would there be a way of identifying if the splines are identical without having to remove the flanges? Like by the tranny model numbers...

Thanks!

Robert

Looking for a 320i 5 speed in the SF Bay area, I've seen a few on Craigslist for $275-350 but would rather purchase from a 02 member.

Thanks,

Robert