Show full size 924Board.org
Discussion Forum of 924.org
 
 FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 
 Technical FAQ924 FAQ (Technical)   Technical924 Technical Section   Jump to 924.org924.org   Jump to PCA 924 Registry924 Registry

New fuel delivery (?) issue?
Goto page Previous  1, 2, 3, 4, 5, 6, 7, 8, 9  Next
 
Post new topic   Reply to topic    924Board.org Forum Index -> 931 Tech.
View previous topic :: View next topic  
Author Message
bureau13  



Joined: 07 Sep 2017
Posts: 357
Location: South Florida

PostPosted: Sun Sep 27, 2020 1:01 am    Post subject: Reply with quote

I may have to. I'm running out of other options I think! I think I know a shop that knows K-Jet (I'll verify but knowing the cars they work on I suspect they do) but I'm sure they don't know the Mittelmotor thing. That being said, it's not exactly complicated to tune it.

I'm really suspecting there may be something wrong with my unit though. At this point I don't know what else it could be, really.

Carrera RSR wrote:
Take it to a dyno assuming they have K Jet knowledge and let them work it out. Then you can try and replicate it on the rollers under any load, speed, rpm and measure fuel pressures, boost and timing all at the same time.......they will either find the fault or it will be tuned so no further issues.

_________________
-----------------------------------------
1982 931
1986.5 Silver 928S
2007 Hummer H3 (Daily Driver)

Past lives (I miss them all):
2004 RX-8 (Wrecked)
1993 RX-7 (Sold)
1987 RX-7 Turbo II (Sold)
1985 RX-7 GSL (Stolen)
Back to top
View user's profile Send private message
Fasteddie313  



Joined: 29 Sep 2013
Posts: 2224
Location: MI

PostPosted: Sun Sep 27, 2020 8:35 am    Post subject: Reply with quote

Could you have too much dwell hurting your coil?
How hot is your coil getting?
_________________
80 Turbo - Slightly Modified
Back to top
View user's profile Send private message Yahoo Messenger
bureau13  



Joined: 07 Sep 2017
Posts: 357
Location: South Florida

PostPosted: Sun Sep 27, 2020 11:39 am    Post subject: Reply with quote

I never really thought to check if the coil is getting hot, but I'll do that.

I don't have a way to measure dwell, I don't think. It would definitely be interesting to swap in another coil and see if the same patter repeats itself although not sure I want to order an $80 sacrifice if I can help it. Hmmm...

Fasteddie313 wrote:
Could you have too much dwell hurting your coil?
How hot is your coil getting?

_________________
-----------------------------------------
1982 931
1986.5 Silver 928S
2007 Hummer H3 (Daily Driver)

Past lives (I miss them all):
2004 RX-8 (Wrecked)
1993 RX-7 (Sold)
1987 RX-7 Turbo II (Sold)
1985 RX-7 GSL (Stolen)
Back to top
View user's profile Send private message
bureau13  



Joined: 07 Sep 2017
Posts: 357
Location: South Florida

PostPosted: Sun Sep 27, 2020 12:03 pm    Post subject: Reply with quote

I was poking around the 123Ignition site, and they had an FAQ about misfires after driving a few miles. That's not exactly what I'm seeing (well, it sort of is, but the miles are cumulative?) Anyway, the reason listed was that the ignition will briefly go into a protection mode if it sees a voltage spike due to a failing voltage regulator. I've been suspecting my alternator is not charging my battery properly, but I have had other priorities so I just stuck it on a trickle charger every few days. In this case, I had it on the charger while awaiting the coil, but removed it after and have not put it back since then.

So, two theories to test here.
_________________
-----------------------------------------
1982 931
1986.5 Silver 928S
2007 Hummer H3 (Daily Driver)

Past lives (I miss them all):
2004 RX-8 (Wrecked)
1993 RX-7 (Sold)
1987 RX-7 Turbo II (Sold)
1985 RX-7 GSL (Stolen)
Back to top
View user's profile Send private message
kondzi  



Joined: 02 Jul 2018
Posts: 143
Location: MZ/Poland/EU

PostPosted: Sun Sep 27, 2020 10:53 pm    Post subject: Reply with quote

Just to be double sure - you have cleaned, retightened and verified all grounding points? With electrics/electronics, especially related to ignition, ground is critical.
_________________
---
Konrad
'89 951 US
'88 Mustang 5.0 LX Convertible (factory specs)
'84 911 Carrera 3.2 RoW (factory specs)
'81 931 RoW (TBD)
'81 Ford Capri 2.8i (factory specs)
'79 Ford Capri 2.9 (heavily modded)
Back to top
View user's profile Send private message
Fasteddie313  



Joined: 29 Sep 2013
Posts: 2224
Location: MI

PostPosted: Sun Sep 27, 2020 11:55 pm    Post subject: Reply with quote

Or.. Possibly not enough dwell at higher rpm not giving the coil enough time to charge??

Idk.. Just a guess..
_________________
80 Turbo - Slightly Modified
Back to top
View user's profile Send private message Yahoo Messenger
bureau13  



Joined: 07 Sep 2017
Posts: 357
Location: South Florida

PostPosted: Mon Sep 28, 2020 2:13 pm    Post subject: Reply with quote

Yes, I did. None of them looked too bad but I did it anyway, but no change.

kondzi wrote:
Just to be double sure - you have cleaned, retightened and verified all grounding points? With electrics/electronics, especially related to ignition, ground is critical.

_________________
-----------------------------------------
1982 931
1986.5 Silver 928S
2007 Hummer H3 (Daily Driver)

Past lives (I miss them all):
2004 RX-8 (Wrecked)
1993 RX-7 (Sold)
1987 RX-7 Turbo II (Sold)
1985 RX-7 GSL (Stolen)
Back to top
View user's profile Send private message
bureau13  



Joined: 07 Sep 2017
Posts: 357
Location: South Florida

PostPosted: Mon Sep 28, 2020 2:18 pm    Post subject: Reply with quote

That wouldn't damage the coil, would it? Given the way this progressed over time, starting with installation of the new coil, makes your previous idea about too much dwell, which could definitely damage a coil. Although, I'm not sure why it would not work under light throttle but flooring it to 5K was just fine. Ugh...none of it makes sense.

Also, as far as I know, there is no way for me to adjust dwell on this distributor. Maybe there is internally...I've sent an email to Mittelmotor, we'll see what they say.

In the meantime, I am getting about 12.3V at the battery while the car is running, so no wonder my battery wasn't staying charged over time. No idea if that is really causing any of these problems, but I'll see if I can't address that while I try to figure out the rest of it.

Fasteddie313 wrote:
Or.. Possibly not enough dwell at higher rpm not giving the coil enough time to charge??

Idk.. Just a guess..

_________________
-----------------------------------------
1982 931
1986.5 Silver 928S
2007 Hummer H3 (Daily Driver)

Past lives (I miss them all):
2004 RX-8 (Wrecked)
1993 RX-7 (Sold)
1987 RX-7 Turbo II (Sold)
1985 RX-7 GSL (Stolen)
Back to top
View user's profile Send private message
kondzi  



Joined: 02 Jul 2018
Posts: 143
Location: MZ/Poland/EU

PostPosted: Tue Sep 29, 2020 7:57 am    Post subject: Reply with quote

Your battery might be close to dead as well. That might explain the low voltage when car running and issues with triggering spark. Can you switch battery to other one just to exclude above?
_________________
---
Konrad
'89 951 US
'88 Mustang 5.0 LX Convertible (factory specs)
'84 911 Carrera 3.2 RoW (factory specs)
'81 931 RoW (TBD)
'81 Ford Capri 2.8i (factory specs)
'79 Ford Capri 2.9 (heavily modded)
Back to top
View user's profile Send private message
chuck21401  



Joined: 20 Feb 2005
Posts: 347
Location: Annapolis, MD

PostPosted: Tue Sep 29, 2020 12:07 pm    Post subject: Reply with quote

bureau13 wrote:


In the meantime, I am getting about 12.3V at the battery while the car is running, so no wonder my battery wasn't staying charged over time. No idea if that is really causing any of these problems, but I'll see if I can't address that while I try to figure out the rest of it.


Did you check the voltage at the fuel pump?
_________________
1981 Porsche 931
Back to top
View user's profile Send private message
bureau13  



Joined: 07 Sep 2017
Posts: 357
Location: South Florida

PostPosted: Wed Sep 30, 2020 7:09 am    Post subject: Reply with quote

It's a fairly new battery and I had it on the trickle charger to the point where it was registering as fully charged. That being said, I've certainly had issues with batteries not lasting very long in South Florida, but generally when that happens you can tell by the way they run the starter (if they do).

Regarding the next question, I didn't check voltage at the fuel pump because it was lower than expected at the battery when running. Although...I think I probably should have at least checked it at the alternatory...it could be low at the battery due to bad wiring as well. So I will check that, and the fuel pump as well.

kondzi wrote:
Your battery might be close to dead as well. That might explain the low voltage when car running and issues with triggering spark. Can you switch battery to other one just to exclude above?

_________________
-----------------------------------------
1982 931
1986.5 Silver 928S
2007 Hummer H3 (Daily Driver)

Past lives (I miss them all):
2004 RX-8 (Wrecked)
1993 RX-7 (Sold)
1987 RX-7 Turbo II (Sold)
1985 RX-7 GSL (Stolen)
Back to top
View user's profile Send private message
bureau13  



Joined: 07 Sep 2017
Posts: 357
Location: South Florida

PostPosted: Fri Oct 02, 2020 11:25 am    Post subject: Reply with quote

FYI, new voltage regulator is now giving me about 13.6V at idle, so I think I've fixed that problem...but the main issue is still there. Now...with a fully charged battery and a working voltage regulator, the problem seems better. But it's still there, so I don't know if it will get worse like before, or if that really was battery voltage-related.

In any case, Mittelmotor suggested I send back the distributor to exchange it through their US distributor TRE Motorsports (I had no idea they even had a US distributor) but TRE hasn't got back to me yet.
_________________
-----------------------------------------
1982 931
1986.5 Silver 928S
2007 Hummer H3 (Daily Driver)

Past lives (I miss them all):
2004 RX-8 (Wrecked)
1993 RX-7 (Sold)
1987 RX-7 Turbo II (Sold)
1985 RX-7 GSL (Stolen)
Back to top
View user's profile Send private message
bureau13  



Joined: 07 Sep 2017
Posts: 357
Location: South Florida

PostPosted: Fri Oct 09, 2020 4:56 am    Post subject: Reply with quote

Is there a way I can change the title of this thread? It's very misleading.

So TRE Motorsports knows nothing about this distributor. Over the phone, they were suggesting there's something wrong with the CD unit but...that is removed from the equation with the Mittelmotor distributor, which I've verified. So in the meantime, I thought I'd put the old distributor back on while I pull the new one out to return, but I can't get the damn thing to start at all now. I've clearly done something dumb. It just cranks, and occasionally coughs/backfires.

I put cylinder 1 at TDC, I have the cylinders set to fire 1-3-4-2, I never removed the CD stuff, just unplugged it, so everything should be there.

The only thing I physically removed was an EGR valve thing that was in the vacuum path to the vacuum advance canister, which I've left unplugged anyway since it wasn't really working in the old setup. Not sure what I've missed here, any ideas?
_________________
-----------------------------------------
1982 931
1986.5 Silver 928S
2007 Hummer H3 (Daily Driver)

Past lives (I miss them all):
2004 RX-8 (Wrecked)
1993 RX-7 (Sold)
1987 RX-7 Turbo II (Sold)
1985 RX-7 GSL (Stolen)
Back to top
View user's profile Send private message
Fasteddie313  



Joined: 29 Sep 2013
Posts: 2224
Location: MI

PostPosted: Fri Oct 09, 2020 5:31 am    Post subject: Reply with quote

You sure you have cyl 1 at tdc on the compression stroke and not on the exhaust stroke?
_________________
80 Turbo - Slightly Modified
Back to top
View user's profile Send private message Yahoo Messenger
bureau13  



Joined: 07 Sep 2017
Posts: 357
Location: South Florida

PostPosted: Fri Oct 09, 2020 5:56 am    Post subject: Reply with quote

I made sure the dot on the crank pulley and the dot on the back side of the cam sprocket were both lining up with the pointer. (I don't seem to have a notch, I have a dot, on the crank pulley, which made me wonder at first but I rotated it around several times, no notch, just a red dot).

Fasteddie313 wrote:
You sure you have cyl 1 at tdc on the compression stroke and not on the exhaust stroke?


Here is one weird thing...after trying to start a few times, I noticed that I had #1 wire going to #4 and vice versa...I numbered them in my head backwards, firewall to radiator, somehow. What's really weird is I was super careful to match what I took off...but I must have messed it up anyway, because there's no way it would have run properly like that. Right? Lol I am questioning myself. But it's correct now. Could I have flooded it, trying to start with the order wrong? I let it sit for a day and tried again, same result.
_________________
-----------------------------------------
1982 931
1986.5 Silver 928S
2007 Hummer H3 (Daily Driver)

Past lives (I miss them all):
2004 RX-8 (Wrecked)
1993 RX-7 (Sold)
1987 RX-7 Turbo II (Sold)
1985 RX-7 GSL (Stolen)
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic    924Board.org Forum Index -> 931 Tech. All times are GMT + 10 Hours
Goto page Previous  1, 2, 3, 4, 5, 6, 7, 8, 9  Next
Page 8 of 9

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


Powered by phpBB © 2001, 2005 phpBB Group