madkaw

Nothing conclusive with the coolant pressure test. 4,5,6 show 180-190 psi on a compression test Next step is mounting back a dizzy and wires to eliminate electrical. Now I am kicking myself for selling my 12-80 dizzy, but I have a spare that a buddy and I share for this purpose. Should take an hour to wire it back up.

Swapping around coils did help define my issue. I am weighing too much on what I am seeing with the timing light. I can't explain why the timing light flickers differently on some coils, but it does. Regardless of what I am seeing with the light, I know for a fact that 4&5 plugs look fouled. Since it is unlikely a carb issue spanning across two different carbs I am beginning to think I have a breach in my HG. These symptoms are similiar to what happened to me in 2011 when i blew a HG then. The car ran alright, but not not 100% . My car didn't overheat or any real symptoms back in 2011, but it failed a coolant pressure test, and that's what I'll be doing when I get home. Maybe got too aggressive with my timing? I probably shouldn't speculate until I know for sure what's up.

Looks good! The taper should be a benefit. I didn't do that with my design, but I think enough volume can help make up for that.

Damn-I'm 51 now.

You need to update your signature with some description. There's hardly a way to answer your question with so little information provided. Engine specifics Carb setting specifics Ignition History Check out my thread triple Mikuni Help in the fuel delivery forum

There's always the chance it's spark related, but those settings seemed to copy over fairly well. Also if it were off, I would think the car wouldn't run and the timing is spot on every single time I check it. My timing was right on the mark too, but the longer I watched the light, the more I saw problems. Not doubting you, but make sure you don't discount anything! I feel your pain dude.

Looks like the 72 I just picked up. I was thinking more on the line of weld building the 'dip" to make it a high quench head.

Thanks Sam. After a while I started thinking to myself I should have swapped coils - duh- to see if it followed , like you said. I could of and should have been yanking on the harness while it's running to see if that gives any results - you know- the basic mechanic stuff. Sometimes we dig to deep for the shallow stuff. 4 of these coils are used. I also remember that the connectors were a bit funky in that there was an additional plastic piece that went on basically between the connector and coil. What if I didn't have that installed? Don't really know what it does. I guess I have grounds to check too! Basics , basics, basics

Never loose sync or no indication of loosing sync. Maybe # 6 coil is the culprit, but it's inconsistent . Coil drivers bad? That would be inside the MS box right?

Well still looking for the miss! I can watch my timing light and see the miss as it happens . #6 cylinder is still the funkiest. Sometimes it flashes light wasted spark and other times it doesn't flash that fast. Fixed the timing at 15 degrees and it's rock steady. No variation with rpm. Checked CAS gap and then tightened the gap - no different. Checking wiring next ? Not sure if changing capture setting will do anything. Same thing about skipping pulses. I don't want to make changes unless I'm sure I want damage anything.

I recently aquired an E-88 head from a member.. As I have searched I have come across numerous threads discusiing the various E-88 heads. I guess there were 4 versions from what I have found. I am attaching pics of the two that I own now. The one on my engine now is from 9/71 . The one I just aquired,(dirty) is from a 72-not sure what month. The 72 seems to look exactly like the E-30 listed early in this thread. I wish there was a pic of an e-31 head in this thread. If I missed it I'm sorry, but thought it was(is) strange that the very first head is not pictured here. Anyway, not sure how you would describe the combustion chamber on this 72, but I laid the straight edge across the chamber to give some perspective. The 9/71 ( clean) head has been unshrouded and milled .012

Mack- do you have a build thread? I'm heading your direction eventually with MS controlled high compression NA.

So what are you using for rpm ? Have you set your timing to a fixed number to see if it smooths out anything? Has your rpm source changed when going from MS1- MS2. Timing light has verified nothing wonky with your spark? I ask all these things because it's the road I'm heading down now. My coils did funny things while testing . I'm back revisiting everything including the possibility of a pull up resistor for my Hall effect sensor.

Still following this hoping to shed light on my issue since they seem closely related-though I have carbs. I think I have eliminated induction issues. Recently my plugs have shown something a miss(pun intended) , so now I am troubleshooting my MS. I have been on the MS forums and there are other issue similiar. Broke, but not broke enough to pinpoint-hate it. Good luck.

PM you

So my idle sounds like 3/4 cam and my AFR's are bouncing. The engine runs like it has a miss or something. After checking everything from carbs to vacuum leaks, I started on the MS. Timing light verifies correct timing. What's weird is if I put the light on each coil, they fire off like machine gun-fast at idle EXCEPT #6, and it's about half speed. Well I guess I don't know how to attach my tune. Hybridz says I can't attach this type file

So I crossed valves off my list- though some were very tight. It made no difference in the way it ran. So I proceeded to pull plugs to do a compression test and 4&5 look black and 6 was headed that way. I had just idled the car for 5 minutes and AFR's didn't indicate that rich, but AFRs weren't steady either. No radical swings though . It seems that I have to turn the pilots out further then normal to get an idle down around 14AFR- at least more then I remember . Now I'm guessing between ignition and carb. 4&5 cylinders tell me it's not just one carb or really not likely carbs-3 looks great. I guess I will still do a compression test to see what it says. Not sure how to troubleshoot the ignition except to try the coils in test mode to see how the spark looks.

And if I don't have one there's a buddy in avon that has lots of 75 parts

Dave, If I have one you can come get it. I'll check later today

Thought I'd update this for now. The FG guy said he would be willing to tackle this but the price to do the mold is not cheap . I didn't expect it to be , but still more then I can shell out right now (1500$) I also have to repair this dash to perfection before he can even attempt a mold. He said as far as a carbon fiber dash probably in the 900$ range for a single unit, but a significant break for a group buy. He would be using prepreg CF which is pretty pricey. The shell itself would be very thin stuff so stand offs would have to be used to mount on original metal frame. The shell would weigh nothing. So where we stand now: I have a daughter getting married in November so all major projects are hold until then. Repairing the dash has to be done right and I don't want to rush. I also have a son with high athletic demands as far as time . So this will be a winter project when things settle done around my place.

Cool set up! I could see where you could be chasing vacuum leaks. I am currently chasing an inconsistant idle with my triples and MS3. I too have the dreaded vacuum log. Have you capped it off to eliminate it. Might want to try the propane torch with a hose to pinpoint possible leaks. How is your MAP signal with your vacuum log? I've read that some have a hard time getting a steady signal from ITB's and that MS has a program for that.

Doesn't look like you are using much force to spin it-hardly any. I'd say if that lube is that tacky, then it is the issue. Some others with rebuild experience may chime in

Well as I suspected my float levels were not same across all carbs. Not too bad off, but I definitely needed to correct the situation. This did NOT correct the erratic throttle. I resynced the carbs with my vacuum log lines pinched off. I noticed when un-pinching the lines my idle got higher(little bit is normal), but seemed also erratic too. Now here's what I'm trying to figure out. With the vacuum log connected I can go down the line and pinch each hose individually to look for vacuum leaks. Nothing happens until I pinch #1 cylinder hose, then the idle drops and seems more even? If I had a leak somewhere in that line, I would think pinching it would do nothing because you would still have vacuum pulling from either side of the hose-right? If the float was wonky, wouldn't it effect both 1&2? I can effect the idle by adjusting just #1 pilot screw in about 3/16 turn. I have not driven the car yet since adjusting floats-stay tuned

Well it seems that my 'studder' during transition has turned into a random issue now along with an erratic idle. The two seem to be tied together, so when my idle gets erratic(way lean on the wideband), I get more lean during transition and cause the studder. So did I really do anything with my bleed pipes that was good? I don't know since the issue is back. Floats pop up in my mind as the culprit. Not sure what else would effect the idle and the transition. These carbs are too clean to have carbon build up on the pilot screws, but I will investigate. I'll pop the tops off tomorrow and start scrutinizing,

Now that I have had the Mikunis for a while and have tuned and tuned I can only imagine the FUN you are going to encounter with turbo Mikunis