Printable Version | Subscribe | Add to Favourites
<<  1    2    3  >>
New Topic New Poll New Reply
Author: Subject: Miss Fire 3500rpm under load
mark.silcock

posted on 22/9/19 at 07:18 PM Reply With Quote
quote:
Originally posted by SPYDER
In an earlier post you said..."it is only running off the crank sensor so the unit cannot detect any engine load, "
So to be clear, it has no TPS or MAP sensor?
Or am I missing something?
It wouldn't be the first time.
If it was forced induction I might suggest reducing the spark plug gap. Worth a try?
I had a similar, but admittedly non load dependant misfire on my Megasquirt install, which was cured by
putting a 10K resistor in line with the VR sensor.
Float bowl fuel levels correct?
Many coil packs have an associated suppressor/capacitor attached? Does yours? Should it have? Is it faulty?


Correct, no MAP sensor or TPS just the crank signal.

Checked the needle valve height but haven't measured the fuel level in the bowl.

View User's Profile View All Posts By User U2U Member
mark.silcock

posted on 22/9/19 at 07:19 PM Reply With Quote
If it is no different with the new crank sensor I will video what it is doing.
View User's Profile View All Posts By User U2U Member
SPYDER

posted on 22/9/19 at 07:37 PM Reply With Quote
Without any sort of load sensor the 3D ignition map you posted has no purpose. I assume it simply runs across the 100%, "full throttle" line.
View User's Profile Visit User's Homepage View All Posts By User U2U Member
mark.silcock

posted on 22/9/19 at 07:39 PM Reply With Quote
Runs across the top line from memory.
View User's Profile View All Posts By User U2U Member
SPYDER

posted on 22/9/19 at 08:46 PM Reply With Quote
I'd prefer the bottom line.
View User's Profile Visit User's Homepage View All Posts By User U2U Member
mark.silcock

posted on 27/9/19 at 04:50 PM Reply With Quote
Ok another update.

So I first off checked the fuel levels in the bowls, one carb was off by about 5mm so adjusted the floats so they are both the same and are approx 26mm +-1mm.

Drove the car and again it's no different.

Crank sensor finally turned up and fitted it to the car.

Drove it and it's no different.

It wasn't running particularly well stationary tonight but still would rev past 3000rpm, probably needs an idle adjustment after the float level change.

Was suggested to try pulling the choke out while its not reving to see if extra fuel would make any different but that didnt do anything either.

Here is a sketchy video.



View User's Profile View All Posts By User U2U Member
SPYDER

posted on 27/9/19 at 07:26 PM Reply With Quote
Could this "rev limit" be due to the Nodiz expecting a load signal and not getting one?

Did you try putting a 10K resistor across the VR sensor?

[Edited on 27/9/19 by SPYDER]

View User's Profile Visit User's Homepage View All Posts By User U2U Member
mark.silcock

posted on 28/9/19 at 09:20 AM Reply With Quote
I am not sure what you mean by VR Sensor? Ah crank sensor? No I haven't and what does that do?

The Nodiz is set to no load so its not expecting any signal.

[Edited on 28/9/19 by mark.silcock]

[Edited on 28/9/19 by mark.silcock]

View User's Profile View All Posts By User U2U Member
procomp

posted on 28/9/19 at 01:19 PM Reply With Quote
When you changed engine was the flywheel changed also or is the new engine and flywheel as it came as complete know running unit Ok.

Reason for asking is that when changing the CPS for a new one it might not be the actual CPS at fault but the housing it fits into. There are 2-3 different housings with differing CPS location within the housing for the Zetec and if the housing and flywheel are not in correct positioning to each other you will get what shows as a CPS issue but its not the actual CPS at fault but its location.
Hope that makes sense.

Matt

View User's Profile E-Mail User Visit User's Homepage View All Posts By User U2U Member
mark.silcock

posted on 28/9/19 at 02:02 PM Reply With Quote
Yeah it does make sense and something I had been thinking about. The flywheel was swapped over along with the crank sensor from the original engine that came with the car. Which from memory was a 1997 silvertop. The crank sensors did look the same but if the blocks are different then that would cause an issue.

How do I check?
Original engine was a Nov 1997
Current engine is a May 1992

[Edited on 28/9/19 by mark.silcock]

[Edited on 28/9/19 by mark.silcock]

View User's Profile View All Posts By User U2U Member
SPYDER

posted on 28/9/19 at 04:02 PM Reply With Quote
The 10K resistor is a well known fix in the Megasquirt community. The problem is noise related and can cause the ECU to miss-read the missing tooth. It's more common on 60 tooth wheels but can show up on 36 tooth types.
To correct my earlier post.... the resistor goes INLINE with the crank sensor, not across it.

View User's Profile Visit User's Homepage View All Posts By User U2U Member
mark.silcock

posted on 29/9/19 at 10:14 AM Reply With Quote
quote:
Originally posted by procomp
When you changed engine was the flywheel changed also or is the new engine and flywheel as it came as complete know running unit Ok.

Reason for asking is that when changing the CPS for a new one it might not be the actual CPS at fault but the housing it fits into. There are 2-3 different housings with differing CPS location within the housing for the Zetec and if the housing and flywheel are not in correct positioning to each other you will get what shows as a CPS issue but its not the actual CPS at fault but its location.
Hope that makes sense.

Matt


Does that imply that the flywheels can be different?

If the CPS is the right one for the block (which is what I ordered) then it should be in the right place? But if the flywheels different as well then it would read wrong.

View User's Profile View All Posts By User U2U Member
mark.silcock

posted on 29/9/19 at 10:29 AM Reply With Quote
quote:
Originally posted by SPYDER
The 10K resistor is a well known fix in the Megasquirt community. The problem is noise related and can cause the ECU to miss-read the missing tooth. It's more common on 60 tooth wheels but can show up on 36 tooth types.
To correct my earlier post.... the resistor goes INLINE with the crank sensor, not across it.


We are going to check the signal with an oscilloscope along with the ECU signal to the coil pack.

View User's Profile View All Posts By User U2U Member
procomp

posted on 2/10/19 at 10:50 AM Reply With Quote
Re flywheel differences, depends on a few things such as Fiesta, CVH, Zetecs 1.6 1.8 2.0 Etc Etc but we have had issues with swapping some lightweight flywheels from old to new engines when not changing the complete CPS and housing.
View User's Profile E-Mail User Visit User's Homepage View All Posts By User U2U Member
RichardB123

posted on 2/10/19 at 11:04 AM Reply With Quote
If you are having flywheel trigger pattern woes.

Surely this aftermarket ignition system can work from a trigger wheel mounted to the front crankshaft pulley.
Like megasquirt/jolt etc.

View User's Profile View All Posts By User U2U Member
mark.silcock

posted on 2/10/19 at 11:55 AM Reply With Quote
quote:
Originally posted by RichardB123
If you are having flywheel trigger pattern woes.

Surely this aftermarket ignition system can work from a trigger wheel mounted to the front crankshaft pulley.
Like megasquirt/jolt etc.


Not 100% sure its a Crank sensor issue yet, yes the Nodiz can run off a twigger wheel on the front pulley.

View User's Profile View All Posts By User U2U Member
mark.silcock

posted on 2/10/19 at 11:57 AM Reply With Quote
quote:
Originally posted by procomp
Re flywheel differences, depends on a few things such as Fiesta, CVH, Zetecs 1.6 1.8 2.0 Etc Etc but we have had issues with swapping some lightweight flywheels from old to new engines when not changing the complete CPS and housing.


What do you mean by housing? It bolts directly to the block, or am I missing something?

View User's Profile View All Posts By User U2U Member
Schrodinger

posted on 3/10/19 at 08:07 AM Reply With Quote
The CPS fits into a housing which fits onto the block and there are different housings/CPS for manual and auto gearboxes.





Keith
Aviemore

View User's Profile E-Mail User View All Posts By User U2U Member
procomp

posted on 3/10/19 at 03:43 PM Reply With Quote
Heres a pic of two. but have found over years 4 different ones.

Wont let me add pictures here but added photo to my page.

https://www.facebook.com/Procomp-motorsport-376574512390043/

View User's Profile E-Mail User Visit User's Homepage View All Posts By User U2U Member
mark.silcock

posted on 4/10/19 at 08:59 AM Reply With Quote
Ah I see, could not remember noticing that but luckily have a photo of the engine code that shows the mount.

Description
Description


Im guessing thats a good result as it should be close to the flywheel?

[Edited on 4/10/19 by mark.silcock]

[Edited on 4/10/19 by mark.silcock]

View User's Profile View All Posts By User U2U Member
mark.silcock

posted on 5/12/19 at 06:42 PM Reply With Quote
Update:

New Nodiz ECU installed and guess what its no different.

So I want to get to the bottom of making sure the crank sensor/housing and flywheel is the right combination.

What do I need to know and how do I check to get it right?

View User's Profile View All Posts By User U2U Member
mark.silcock

posted on 5/12/19 at 08:29 PM Reply With Quote
Did they ever do an RS1800 Automatic?

Looking through the photos the original engine was a manual.

Can you tell from engine numbers?

would the engine even start with an auto housing?

[Edited on 5/12/19 by mark.silcock]

View User's Profile View All Posts By User U2U Member
paulf

posted on 5/12/19 at 10:02 PM Reply With Quote
If you are using the advance curve on the top line of the map then it has probably got to much advance at 3500 and above , what happens if you reduce it to about 15 degrees across the map.The figures across the top of map are more like wht it should have on overrun.
Paul

View User's Profile View All Posts By User U2U Member
mark.silcock

posted on 5/12/19 at 10:05 PM Reply With Quote
It runs exactly the same with the base map on the new Nodiz that is much more conservative.

We have loaded a few different maps and they have made no difference to the missfire.

View User's Profile View All Posts By User U2U Member
mark.silcock

posted on 6/12/19 at 12:03 PM Reply With Quote
What about poor shielding from the CPS? What are the symptoms of that?
View User's Profile View All Posts By User U2U Member
<<  1    2    3  >>
New Topic New Poll New Reply


go to top






Website design and SEO by Studio Montage

All content © 2001-16 LocostBuilders. Reproduction prohibited
Opinions expressed in public posts are those of the author and do not necessarily represent
the views of other users or any member of the LocostBuilders team.
Running XMB 1.8 Partagium [© 2002 XMB Group] on Apache under CentOS Linux
Founded, built and operated by ChrisW.