Jump to content

yet another no spark during crank, but this one is different. maybe...


blackedoutjedi

Recommended Posts

I spent some time going through post looking for info that might be useful but didn't see anything that described my problem. This is my first time running a Link ECU and truth be told I probably should have picked a more standard build to start with. Although I'm experienced in wiring and performance in the automotive world from a build standpoint I am brand-new to tuning and could use some help.

The Build:

Car. 1968 volvo 122s

Engine. 1975 b20 that was originally running kjet injection. I cut the tbody off the intake and welded a flange to run a 2005 WRX tbody. I milled out the stock injector bosses to accept the WRX injectors and then made a common rail to feed them. I machined the crank hub and attached a 36-1 wheel with a reluctor sensor and using the stock bosch 2 wire hall effect distributor for cam refrence

computer. G4X MonsoonX, Link wideband kit, Link ignitor.

problem is I cant get it to start. Fuel pump will prime, and it cranks over but I don't have any spark.

when viewing data during cranking in the tunning window I can see the fuel pump and injectors status switch to active during cranking but engine speed stays at 0. Figured I messed up on wiring the triggers so I tested at the ECU connector and both triggers are sending signal during cranking. When I ran the ignition test the coil sparks. I tried to view them in the trigger scope but it doesn't show any movement.

finally I was able to see engine speed during cranking in the Logging window but only when I was recording but still no start. I have attached my tune and the Log, hopefully I did it right. im pretty sure the problem is going to be something not set right in the tune and any help or pointers would be appreciated 

 

1968 volvo 122s b20 base setup.pclx crank, no start.llgx

Link to comment
Share on other sites

There is no dwell showing when cranking, usually this this means it is not happy about some part of the triggering.  Can you do a triggerscope while cranking and attach the file here.  Make sure you only click the capture button while the engine is cranking.  

Link to comment
Share on other sites

It does look like trigger 2 is reluctor and it also looks like you need to swap the wires around on both sensors. The falling edge should be the sharp almost vertical drop but both are showing the falling edge as a gentle slope

Link to comment
Share on other sites

Yeah, Vaughan is right, wrong polarity on both sensors and cam is a reluctor.  

Also, your current cam pattern is not suitable for sync as it is symetrical on both crank rotations - ie there is no way the ecu will be able to tell if you are on the first crank revolution or 2nd.  I would suggest grinding 3 teeth off so there is just a single tooth left in the distributor.

Link to comment
Share on other sites

2 hours ago, Vaughan said:

It does look like trigger 2 is reluctor and it also looks like you need to swap the wires around on both sensors. The falling edge should be the sharp almost vertical drop but both are showing the falling edge as a gentle slope

thanks Vaughan, I made the changes and scoped it. my battery was getting a little low but now I have spark.

TriggerScopeLog 2nd.llgx PC Datalog - 2021-06-27 5;09;55 pm.llgx

3 hours ago, Adamw said:

Yeah, Vaughan is right, wrong polarity on both sensors and cam is a reluctor.  

Also, your current cam pattern is not suitable for sync as it is symetrical on both crank rotations - ie there is no way the ecu will be able to tell if you are on the first crank revolution or 2nd.  I would suggest grinding 3 teeth off so there is just a single tooth left in the distributor.

Adam, thanks for the help. I have a dwell reading now.

in regards to the distributor should I grid off teeth that are attached to the center shaft that rotates the rotor or the housing side, or both? also is it going to matter what tooth I leave? I have attached a picture of the distributor I'm running, the picture is not of my distributor but its the same as what I'm running. also will there need to be changes made on the ignition side? if the Link is picking 4 spikes every rotation of the distributor and now will only see one will it still spark at the correct interval?

bosch volvo dist..jpg

Link to comment
Share on other sites

2 hours ago, blackedoutjedi said:

in regards to the distributor should I grid off teeth that are attached to the center shaft that rotates the rotor or the housing side, or both?

Im not too sure as I have never messed with one like that, but my logic says you are going to have to remove 3 rotor teeth and 3 stator teeth.

 

2 hours ago, blackedoutjedi said:

also is it going to matter what tooth I leave?

No. Any is fine.

 

2 hours ago, blackedoutjedi said:

also will there need to be changes made on the ignition side? if the Link is picking 4 spikes every rotation of the distributor and now will only see one will it still spark at the correct interval?

For now you can set sync mode to none and it should run - just fuel injection wont be timed correctly.  When you have modified the distributor then change sync mode to "Cam pulse 1X".

Link to comment
Share on other sites

11 hours ago, Adamw said:

Im not too sure as I have never messed with one like that, but my logic says you are going to have to remove 3 rotor teeth and 3 stator teeth.

 

No. Any is fine.

 

For now you can set sync mode to none and it should run - just fuel injection wont be timed correctly.  When you have modified the distributor then change sync mode to "Cam pulse 1X".

would it be posable to just set it to cam pulse window so it only looks for the pick up at a specific position? That way the ECU will just ignore the other 3 teeth.

Link to comment
Share on other sites

6 hours ago, blackedoutjedi said:

would it be posable to just set it to cam pulse window so it only looks for the pick up at a specific position? That way the ECU will just ignore the other 3 teeth.

No, because you will also have a tooth on the cam in exactly the same "window" on the 2nd crank revolution.  You need something unique that occurs on the first rev but not the 2nd - or vice versa.  For example if you had 3 teeth on the cam it would be ok as you would have 2 teeth on one rev and a single tooth on the next rev so you can tell the difference between the two.  

Link to comment
Share on other sites

13 minutes ago, Adamw said:

No, because you will also have a tooth on the cam in exactly the same "window" on the 2nd crank revolution.  You need something unique that occurs on the first rev but not the 2nd - or vice versa.  For example if you had 3 teeth on the cam it would be ok as you would have 2 teeth on one rev and a single tooth on the next rev so you can tell the difference between the two.  

yeah. I broke down the theory in my head right after I asked the question. no way to make the ECU ignore the signals on the 2nd rev but not the first.

I got it running by switching to none for trigger2 sync like you suggested and switched fuel to multi-point group. It fires right up and idles. Thanks Adam. the idle is a little high 900-1300rpm and I didn't see an option to change desired idle. Any insight? I didn't let it run very long its 112F out right now and I didn't want spend much more time out there.

Also, I'm going to modify the distributor tonight and try to get it to run sequential later this week when the weather cools off  but I'm having a hard time understanding how to determine sync tooth position or if I even need to. reading the description it sounds like its for DOHC or twin cam engines, is that correct? when it refers to a cam sync point in relation to the missing crank tooth position is that just TDC? sorry if some of these questions seem obvious. Like I said, I'm new.

Link to comment
Share on other sites

6 hours ago, blackedoutjedi said:

the idle is a little high 900-1300rpm and I didn't see an option to change desired idle. Any insight?

Does it have an idle valve?  You have one assigned to Aux 1 but not much else is set up.  It is commanded to 0% anyway so if it is idling too fast like that then you need to close the throttle some.  Idle valve PWM frequency should normally be around 150-200Hz and you adjust the values in your base position table to achieve the desired speed.  

 

6 hours ago, blackedoutjedi said:

Also, I'm going to modify the distributor tonight and try to get it to run sequential later this week when the weather cools off  but I'm having a hard time understanding how to determine sync tooth position or if I even need to. reading the description it sounds like its for DOHC or twin cam engines, is that correct? when it refers to a cam sync point in relation to the missing crank tooth position is that just TDC? sorry if some of these questions seem obvious. Like I said, I'm new.

Sync tooth is not usually relevant when you have a single tooth on the cam - set it to 1.  

Link to comment
Share on other sites

On 6/29/2021 at 4:20 PM, Adamw said:

Does it have an idle valve?  You have one assigned to Aux 1 but not much else is set up.  It is commanded to 0% anyway so if it is idling too fast like that then you need to close the throttle some.  Idle valve PWM frequency should normally be around 150-200Hz and you adjust the values in your base position table to achieve the desired speed.  

I'm running a valve off a 2005 WRX. its a 3 wire but when I looked up the wire diagram for an 05WRX it shows only one wire going to the ECM then a ign. 12v and ground so that's how I hooked it up. I have been messing with settings and I have it running now but no IAC control, it was stuck open so I bolted up a block off plate and and opened the throttle valve until it would idle hot until I figure what's up with the IAC. and its running super rich, 10.4:1 or so. I have an appointment with the tuner on Monday but I really want to have the base setup dialed in better so I can at least drive it to them. the car is super low and hard to get on the trailer.

here's my tune and a log at idle. If there's anything obvious or if anyone has any pointers I would appreciate it, trying to get a better understanding 

PC Datalog - 2021-07-2 6;46;18 pm.llgx 1968 volvo 122s b20 base setup 4th wideband.pclx

Link to comment
Share on other sites

To lean it up just use the master fuel setting as a rough adjustment to get it somewhere close.

It looks like your alternator may not be working so check that before tuning.

For the idle valve, to confirm wiring and valve actually works, go to the idle speed controls settings (engine off), set aux 1 to test pwm and temporarily change frequency to 10Hz, you should hear the valve clicking it it works.

Link to comment
Share on other sites

12 hours ago, Adamw said:

To lean it up just use the master fuel setting as a rough adjustment to get it somewhere close.

It looks like your alternator may not be working so check that before tuning.

For the idle valve, to confirm wiring and valve actually works, go to the idle speed controls settings (engine off), set aux 1 to test pwm and temporarily change frequency to 10Hz, you should hear the valve clicking it it works.

I dropped the master fuel from 13 to 10 and it brought AF to 13.3 at idle, at least now it wont foul the plugs.

I spotted the voltage when I was logging. I had been running the factor 1974 Alt. and had relocated the regulator to under the intake trying to clean up the engine bay, guess it didn't like the heat. this morning I made a bracket and installed an SI alt, fixed.

I tried bench testing the IAC and its broken. I got the Tbody used so I don't know if it was broken already or if I fried it because its wired wrong. I ordered a new one this morning.

thanks again Adam, super helpful.

 

Link to comment
Share on other sites

  • 3 months later...

hey Adam, I've been working on the car trying to get it more reliable and its pretty close but I'm having an issue with it dropping all the timing for 3-5sec and then it comes back up while driving. at least that's what it seems like. when it happens I can hear the change in the intake and there's a significant loss of engine power for a few sec. then it switches back to normal. any ideas?

Link to comment
Share on other sites

You've got a problem with your trigger, the RPM momentarily drops to zero, so the ignition timing is held at the idle ignition target during the startup hold/decay. 

Do a trigger scope at about 2000RPM and we will see if it holds any clues.

WAQ8dqt.png

Link to comment
Share on other sites

16 hours ago, Adamw said:

You've got a problem with your trigger, the RPM momentarily drops to zero, so the ignition timing is held at the idle ignition target during the startup hold/decay. 

Do a trigger scope at about 2000RPM and we will see if it holds any clues.

ok, I did a few scopes hoping to catch it while it was happing. the last 2 scopes are during the actual event but I'm not seeing any change in the triggers.

also did another log. you can see that it doesn't always lose the cam trigger when it happens. but I did find out that it wont happen until after the engine gets to temp (185degF) 

 

Log. https://1drv.ms/u/s!AstISA8553ZsgQBLkrlRjHddr6uI?e=klxlPB

scopes:

1  https://1drv.ms/u/s!AstISA8553ZsgQZb3C_0X5Ovi-5Z?e=ZSbYN4

https://1drv.ms/u/s!AstISA8553ZsgQQVDILEIDgbwkQn?e=2ysubV

https://1drv.ms/u/s!AstISA8553ZsgQH6rbHnzTnwOUbO?e=RpTe2S

Link to comment
Share on other sites

I dont see anything obvious in those scopes, so it must be something intermittent.  With the engine running at fast idle, can you go around and shake/tug/wiggle the loom, concentrating especially around trigger connections/plugs/splices/sensor grounds etc, in case there is an intermittent bad connection.  It might pay to try another crank sensor also if they arent too expensive/hard to find.

Link to comment
Share on other sites

  • 2 weeks later...
On 10/11/2021 at 4:18 PM, Adamw said:

I dont see anything obvious in those scopes, so it must be something intermittent.  With the engine running at fast idle, can you go around and shake/tug/wiggle the loom, concentrating especially around trigger connections/plugs/splices/sensor grounds etc, in case there is an intermittent bad connection.  It might pay to try another crank sensor also if they arent too expensive/hard to find.

did a wiggle test and didn't notice anything come up. both triggers are running the shielded/insulated wiring that came on the link harness direct from ecu to the sensors. no splices, and both sensor connections are correctly crimped using new factory Bosch/Deutsch connectors. Battery cables are new and built using #2 welding cable. engine is grounded on all 4 corners. sensor grounds connections are clean and tight. cam sensor is a modified stock distributor. I pulled it apart, everything looks good and clean. everything on the crank trigger looks good. clearances are correct, sensor bracket is secure. The sensor is from a 2003 Focus. I ordered a new one but it doesn't appear to have a high failure rate.

Could the problem posable be in the tune or the settings? maybe I have something set up wrong?

Link to comment
Share on other sites

No I dont see anything wrong in terms of set up or tune.  If you remind me on Monday I pass the log and scope on to one of our firmware engineers for a second set of eyes but nothing jumps out at me.  It still seems more something intermittent that we havent captured yet.  

A couple of things to do in the meantime:

  1. Get us some more triggerscopes at about 2000rpm or whatever conditions the RPM spike most often occurs at.  it is pretty intermittent so one may just capture something.
  2. Try setting sync mode to none on trigger 2.  The ecu will then ignore the cam sensor.  with no sync the engine sometimes wont start - if it desnt start, stop cranking for a second, then try again.  It should start approx 50% of attempts.  If you still get trigger errors with the cam sensor turned off then at least it rules that out and we can concentrate more on the crank.
Link to comment
Share on other sites

  • 2 weeks later...
On 10/22/2021 at 1:43 AM, Adamw said:

Get us some more triggerscopes at about 2000rpm or whatever conditions the RPM spike most often occurs at.  it is pretty intermittent so one may just capture something.

Problem is defiantly getting worse. After it gets to running temp it will do it at idle and even stall occasionally. I swapped the crank sensor but it didn't seem to change anything. I also went through and rechecked all my grounds and by-passed the vehicle wiring basically wired the motor up like and engine run stand just to isolate it from the rest of the car but it didn't make a difference. I was able to capture a few scopes and record logs but the ecm kept disconnecting.

scope1 @ Idle  https://1drv.ms/u/s!AstISA8553ZsgQ3EssgI3JrYGgUL?e=fYSyym

scope2 @ Idle  https://1drv.ms/u/s!AstISA8553ZsgQvy7QmDXrv208ph?e=OG7npG

scope3 @ Idle  https://1drv.ms/u/s!AstISA8553ZsgQmWMWsSr1GXiVzn?e=DBG46a

Scope Just Off Idle  https://1drv.ms/u/s!AstISA8553ZsgQqxBzoQqwTrs_t-?e=k3ocuQ

Log Hot Idle Stall  https://1drv.ms/u/s!AstISA8553ZsgQzAwh8b5AJ6qTna?e=cASPud

Log Idle To 2K Lost Comm  https://1drv.ms/u/s!AstISA8553ZsgQgTnDdFua-t_9Rf?e=9HueMx

Log Idle To 2K Timing Drop And ECU Disconnect  https://1drv.ms/u/s!AstISA8553ZsgQcM8DVjojtrBnB0?e=bhp7o5

On 10/22/2021 at 1:43 AM, Adamw said:

Try setting sync mode to none on trigger 2.  The ecu will then ignore the cam sensor.  with no sync the engine sometimes wont start - if it desnt start, stop cranking for a second, then try again.  It should start approx 50% of attempts.  If you still get trigger errors with the cam sensor turned off then at least it rules that out and we can concentrate more on the crank.

I haven't actually switched trigger 2 to none but I did unplug it while it was running and it made no difference. Realize thats not the same as turning it off and I'm going to be trying that in the next few hours. 

Link to comment
Share on other sites

Im suspicious there is possibly a random spike of electrical noise getting into the trigger circuit intermittently.  

What does it have for an ignition system?  Does it have resistor spark plugs?  Supressor on the coil power supply?

One other change I wouyld make is change the sync tooth in trigger 1 settings to "1", I dont think it is the problem but sync tooth 1 will give more room for error.

Link to comment
Share on other sites

1 hour ago, Adamw said:

Im suspicious there is possibly a random spike of electrical noise getting into the trigger circuit intermittently.  

What does it have for an ignition system?  Does it have resistor spark plugs?  Supressor on the coil power supply?

Im using the Link 3 channel Igniter (only running the one channel, Distribution is still being handled via the distributor), an MSD 8207 Coil no suppressor Powered on its own Relay and NGK BP6HS plugs. only contamination I can picture would possible spark jump in the distributor interfering with the cam trigger. I will switch it off and disconnect it tomorrow. if it is the issue then I can switch to a coil pack set up and run waste spark.

 

 

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...