Jump to content
HybridZ

engine explosion/backfire


Recommended Posts

Ah..........the old "disconnected the coil wire but left the distributor plugged in when priming my new engine thereby sending unburnt fuel/air mixture into the exhaust where it ignited once I cranked it with coil wire connected back up".

 

The upside is that the girl was too startled to razz you any further.

 

You didn't even flinch!...I would have jumped a mile.

 

Did it do this more than once?

 

If not, what did it do?

 

I've seen properly timed cars do that.

 

If you're worried about timing, you unplug the injectors, crank it, and use a timing light to see if cylinder 1 is close to where it should be on the timing marks.

 

If you do that, be aware that there could be residual fuel in the intake that could cause the engine to possibly start even with injectors unplugged and that just uplugging the spark plug wires could cause high voltage sparks to seek ground through a wire or component....which might damage the ecu.

 

If it were me, I would crank it again as is and use the timing light to see if it's close and hope it doesn't happen again...........if it came from the intake.

 

If it came from the exhaust, then you can relax since you won't be worried about blowing a silicone coupler off of a pipe and taking it in the eye.

 

Don't let that discourage you, you're so close to it running.

Link to comment
Share on other sites

sister and she's 14. i hope you're proud of yourself michael jackson.

Hah my keen senses told me a female was around. :]

 

Only 4 years off! Perfect!

:coollook:

 

I'm kidding, but you had a disappointed face for a pop. I don't understand. I had water spewing out of my thermostat first start and everyone screamed at me. Oh and I didn't prime the oil pump we didn't have oil pressure at first. All lessons learned!

 

http://www.youtube.com/watch?v=wcN9bIYFPgU

Link to comment
Share on other sites

The first time I started my Z I was using a remote starter so I could play with the carb after it fired up. Well, I had a massive intake manifold leak at the head, so when I fired it up for the first time it revved up to around 4000 RPM, held for a few seconds, then died. Open header in the garage...yup, I just about wet myself. By the time I was done fumbleling around trying to get to the keys out of the ignition, it was dead. Nice way to break in a new engine. So, one little pop not so bad! (BTW, it runs great now)

Link to comment
Share on other sites

sister and she's 14. i hope you're proud of yourself michael jackson.

you watch yourself my jokes are killer (check date o.0)

 

Haha, I can't stop watching your video! Its just too funny for some reason.

 

She doesn't sound 14. Tim, I think you're lying to me.

if you check out my most recent, that's my girlfriend's laugh ahhahah but yeah i kinda sorta got it running, just having some problems cuz everytime i try to give it air it dies. my vacuums are solid, my afms on right, i'm just twiddling my fiddle right now trying to figure out whats going on...

Link to comment
Share on other sites

Check your throttle position sensor to see if the switch is on only when the car is at dead idle and make sure you didn't use any conductive silicone on any of the connector boots whether on the tps or the air flow meter.

 

Also........are you running the turbo injectors with the turbo ecu?

Link to comment
Share on other sites

Check your throttle position sensor to see if the switch is on only when the car is at dead idle and make sure you didn't use any conductive silicone on any of the connector boots whether on the tps or the air flow meter.

 

Also........are you running the turbo injectors with the turbo ecu?

 

yeah i'm running the turbo injectors and ECU.

I tested the AFM and TPS continuity to the ECU and they both check out perfect.

With the car in its really rough idle state:

I can unplug the TPS without any change

If i unplug the AFM, it starts to die faster, and when i plug it back in it will rev up and then start to die slowly again.

here's my TPS box

Photo0633.jpg

I'm thinking the problem might lie in this large object coming off the TB which I just noticed TODAY.:mrgreen:

Photo0632.jpg

My intake was from a PO and is a N42 non-egr, and this huge thing coming off the TB right before the plate has a vaccuum line , a weird plug and a flathead screw at the bottom (underneath rubber boot) . I'm thinking IAS? There is a 3/8" hole and a 1/4" hole inside the TB running down into the BBT -> "big black thing." ;P

 

P.S. if this has anything to do with something I'm idling at 15* btdc

Link to comment
Share on other sites

15 btdc is what I have my L28et at.

 

The tps should only have continuity at zero throttle opening (idle position).

 

I find an unbelievable amount where somebody adjusted the throttle body open to compensate for low idle and ending up having the idle switch never making contact because of the throttle opening.

 

This will throw off timing since it is different with the switch in the on position than off for the same throttle opening.

Link to comment
Share on other sites

 

I find an unbelievable amount where somebody adjusted the throttle body open to compensate for low idle and ending up having the idle switch never making contact because of the throttle opening.

 

This will throw off timing since it is different with the switch in the on position than off for the same throttle opening.

 

http://atlanticz.ca/zclub/techtips/tps/index.html

this is how my tps is set, once you push it to about the 1500rpm mark it loses contact with the idle and i'd say about 1/2-5/8 throttle it hits the WOT marking (which actually just goes to nothingness)

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...