Sr20det won?t even try to start

[Sr20probs]

Hey guys I have a freshly rebuilt sr20det that is timed correctly, has spark and fuel but it?s not even trying to fire. When i test the spark with my megasquirt it?s great, but when I crank it with the plug out it sparks every so often. Grounds are good. Is it the crank angle sensor? I?m at a loss at this moment.

[zombiewolf513]

check the spark plug gap?

[Sr20probs]

Yes the plugs come .032 that wouldn’t cause it to not start would it?

[S14rebuild]

The spark plug only fires when that cylinder is at tdc compression stroke. Not suppose to fire nonstop

Engine is fresh rebuilt?.... check mechanical timing and then make sure ur CAS is intalled properly aswell

[Sr20probs]

Mechanical timing seems to be perfect, I used the mazworxs timing chain tool and put so much patience into it. I have a picture too it lines up perfect. It’s a red top and when it’s lined up the cas lines up with the notch on the right.

[S14rebuild]

Maxworks timing tool only shows the cams... balancer mark and from timing cover pin need tobe lined up, thats if the chain is on correctly on the crank sprocket.

As for the cas

https://frsport.com/How-To-Set-Crank-Angle-Sensor-CAS-Timing-on-the-SR20DET-Engine_t_25.html


Idk about notches..just dots.

[Sr20probs]

Yes crank is properly lined up on the crank sprocket I made sure of that because I had it jump a tooth when I resealed it and went to line up the marks. I couldn’t get it. When I took off the timing cover I realized it jumped a tooth so I redid it very carefully and it lined up perfectly. It was on an engine stand when this happened.The crank lines up on the second mark with the dark links on the dots in the correct Way. The timing chain has about a 1/4” slack as according to mazworx instructions. I believe the CAS is lined up right. Am I wrong?

[zombiewolf513]

post the pictures of the mechanical timing.

[S14rebuild]

Yes crank is properly lined up on the crank sprocket I made sure of that because I had it jump a tooth when I resealed it and went to line up the marks. I couldn?t get it. When I took off the timing cover I realized it jumped a tooth so I redid it very carefully and it lined up perfectly. It was on an engine stand when this happened.The crank lines up on the second mark with the dark links on the dots in the correct Way. The timing chain has about a 1/4? slack as according to mazworx instructions. I believe the CAS is lined up right. Am I wrong?


With no pics how would we know?

[Sr20probs]

for some reason its not uploading the picture. i emailed it to myself to upload it. any ideas? not to sound weird but i can leave my email or phone number to send it. its really getting annoying lol.

[Sr20probs]

978-944-5062 text me and i can send the picture and get an opinion

[S14rebuild]

imgur upload or imageshack..copy and paste the link....

I dont text dudes...

[Sr20probs]

https://imageshack.com/my/images here i didn't even know about these websites. lol just lookin for a answer hopefully this helps.

[S14rebuild]

Def dont see ur pics..... gotta post the specific links to that picture...

[Sr20probs]

https://imagizer.imageshack.com/v2/320xq90/r/922/1jYOc7.jpg

[zombiewolf513]

https://redirect.viglink.com/?format=go&jsonp=vglnk_160005011318710&key=44dc742c6ae854c912590be5122f2e42&libId=kf1w5iuh010004j7000DAqrx758oe&loc=https%3A%2F%2Fzilvia.net%2Ff%2Fshowthread.php% 3Ft%3D677513&v=1&opt=true&out=https%3A%2F%2Fimagizer.imageshack.com%2Fv2%2F3 20xq90%2Fr%2F922%2F1jYOc7.jpg&ref=https%3A%2F%2Fzilvia.net%2Ff%2Fsearch.php%3Fse archid%3D17443338&title=Sr20det%20won%3Ft%20even%20try%20to%20start% 20-%20Zilvia.net%20Forums%20%7C%20Nissan%20240SX%20(S ilvia)%20and%20Z%20(Fairlady)%20Car%20Forum&txt=https%3A%2F%2Fimagizer.imageshack.com%2Fv2%2F3 ...922%2F1jYOc7.jpg

reposting for a :newbie:

[Sr20probs]

Is this wrong?

[S14rebuild]

Looks good.

What about ur cas? Posted the link to install properly....is that correct?

[Sr20probs]

https://imagizer.imageshack.com/v2/320xq90/r/924/J4bNKi.jpg Here you go hope this is good as well

[S14rebuild]

Thumbs up...

So spark, fuel, air, compression......what u missing?

[Sr20probs]

Update, fuel only sprays with megasquirt but not when cranking. Explains why it won’t start. Any ideas?

[S14rebuild]

Guessn u have a laptop accessing the megasquirt setup

Are u seeing cas triggers?

Injectors all share a common wire color for 12postive with key on

Ecu grounds each injector to fire it

[Sr20probs]

Thank you I’m gonna have to try that.

[Krazy719]

I would definitely try retiming the ignition timing you can have it give you spark but not firing in the right order give it a shot literally had this problem today


Sent from my iPhone using Tapatalk

[Sr20probs]

How would go about doing that without questioning it haha

[Krazy719]

Go ahead & put the motor on tdc then pull off the cap on the distributor check if the rotor is on cylinder one if it isn?t pull the distributor out & reset it & if it is on cylinder one I would still pull it out & reset it it could be off a tooth & not firing right best of luck man also what you can do is put some starter fluid in the intake if she back fires from it it?s definitely your ignition timing if you believe everything else is set on timing correctly


Sent from my iPhone using Tapatalk

[Sr20probs]

The mechanical timing wouldn’t line up if it was wrong correct? And everything seems good. Has to be that.

[Krazy719]

No the distributor timing is separate so who ever put it together put the mechanical timing correct & the distributor timing would be separate so don?t mess with the mechanical timing just the distributor timing


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[S14rebuild]

Theres no distributor, cap, or rotor.... its an sr20det


I posted you the link already on how to install the cas CAM ANGLE SENSOR

follow it

[Krazy719]

Dang that suck I was going off of my Kat but definitely sounds like the cas


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[Sr20probs]

I did man still nothing I’ll keep trying to figure out why it’s not spraying fuel while cranking

[S14rebuild]

Injector pulse comes from a signal from the cas... it tells the ecu when to ground each injector driver, which fires the fuel injector.


Have u checked to see if u have that signal via cranking the engine and using the monitors on the megasquirt software?

[Sr20probs]

I have not, I definitely will tho sorry this megasquirt thing is all new to me.i appreciate the time to reply with detailed responses.

[Sr20probs]

I have everything ready to install the CAS, one thing tho on the FRS post is the dots seem to be opposite, like my right dot is lower than the left, every video I?ve seen the lower dot is on the left. Heres a picture of how the Dots are positioned. https://imagizer.imageshack.com/v2/320xq90/r/923/GwW7Ol.jpg

[S14rebuild]

Yea, its s diffrent version of cas...i have the same one u do...u got it installed right. Even if it was a tooth off, if u turn it all tje way left or right it will still start.

But were at a point of no injector pulse..... even if u took the cas out, plugged it in..turn the key on and spin the cas by hand, u should hear the injectors fire/click.

Please check for cas signal on megasquit

[Sr20probs]

With my CAS lined up on the lower dot on the right, is trigger wheel correct? https://imageshack.com/i/poFV22Arj

[S14rebuild]

Yea, its s diffrent version of cas...i have the same one u do...u got it installed right. Even if it was a tooth off, if u turn it all tje way left or right it will still start.

But were at a point of no injector pulse..... even if u took the cas out, plugged it in..turn the key on and spin the cas by hand, u should hear the injectors fire/click.

Please check for cas signal on megasquit


Do this.......

[Sr20probs]

Going to do it now, where can I find it on tinder studio and any tips before?

[Sr20probs]

Plugged in my CAS I heard some clicking from the injectors for a little bit then it stopped. Unplugged it and Plugged it back in then nothing. I turned my fuel pump on, 43psi, and nothing

[S14rebuild]

Well, what are u missing? Postive 12volt or ur pulsing ground on the injectors?


Also id recommend tryn another know good cas.

[Sr20probs]

Okay so where do I go to check the 12v and ground on tuner studio?

[Sr20probs]

Now I’m getting slight pops with fuel pump on . That’s it tho

[Sr20probs]

Update. Have fuel from all 4 injectors. Have spark at all 4 plugs. Plugs are covered in fuel. Mechanical timing is correct. CAS is stabbed correctly. When using starter fluid it will backfire out of the intake. Injectors seeem plugged in right. Can’t figure this out. Bad CAS?

[metako42]

This is a long shot but did you remove the CAS chopper plate from the CAS? If so, you might have installed the chopper plate backwards like I once did. Soon as I flipped it the thing started.