96 burb 7.4 misfire after 5.0 injectors

[BeXtreme]

I can connect for sure.... would this be contributing to my potential/likely vacuum leak?? Same question for the missing check valve for evap..
Thanks for your help.

Yes. If you have it running and can feel vacuum on those lines... its a vacuum leak. I'm still not sure what you mean by the "missing check valve". The picture you keep posting is of a cap being present.

 

[mehcs]

Yes. If you have it running and can feel vacuum on those lines... its a vacuum leak. I'm still not sure what you mean by the "missing check valve". The picture you keep posting is of a cap being present.

Yeah, that's not my truck and the easiest way for me to explain is a picture of what I'm missing.

I'm still boggled as to why these missing lines didn't create issues prior to me replacing the injectors. ON top of that, when I got to removing the fuel rail the existing vacuum line off FPR was open to air as well.

I'll button these up and try the carb cleaner trick.


Can anyone tell me about the ignition timing advance on cylinder #1?? i'm at -29deg. Timing advance is +29deg. What is it supposed to be?
Any relation to the CAM retard which is at -2.8deg at idle.. Don't know at 1200 rpm cuz truck will die if touch throttle? Just wondering if I have timing issue also.

 

[mehcs]

Yeah, that's not my truck and the easiest way for me to explain is a picture of what I'm missing.

I'm still boggled as to why these missing lines didn't create issues prior to me replacing the injectors. ON top of that, when I got to removing the fuel rail the existing vacuum line off FPR was open to air as well.

I'll button these up and try the carb cleaner trick.


Can anyone tell me about the ignition timing advance on cylinder #1?? i'm at -29deg. Timing advance is +29deg. What is it supposed to be?
Any relation to the CAM retard which is at -2.8deg at idle.. Don't know at 1200 rpm cuz truck will die if touch throttle? Just wondering if I have timing issue also.

Correction : spark advance +29deg

 

[Tan1998K2500]

As long as you have a line from your evap canister to your evap solenoid, it'll be fine. You don't really need that green valve. You honestly might be fine even without the line most of the times as that solenoid only opens occasionally

Tbh, when it comes to timing advance and stuff, I dont really know what to look for. But, the engine will mess with timing and everything because the o2 sensors are trying to correct for the excess air. That's why it's important to figure out all of the vacuum leaks first

 

[mehcs]

As long as you have a line from your evap canister to your evap solenoid, it'll be fine. You don't really need that green valve. You honestly might be fine even without the line most of the times as that solenoid only opens occasionally

Tbh, when it comes to timing advance and stuff, I dont really know what to look for. But, the engine will mess with timing and everything because the o2 sensors are trying to correct for the excess air. That's why it's important to figure out all of the vacuum leaks first

So I’m ready to pound my head against the wall. While attempting vacuum check I see coolant dripping in corner where gasket meets china rail, again…..This is exactly why I tore down the engine to fix.

Shoulda taken it to a shop I suppose. Didn’t use rubber felpro gaskets but thick bead of RTV and all other tricks I’ve read on here.

My thread is becoming a hot mess. Everyone run……

 

[Schurkey]

I'm also curious about the "Ignition timing advance for #1 cylinder" at -29deg. Also the spark advance. Can anyone tell me if this is normal range?

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Can anyone tell me about the ignition timing advance on cylinder #1?? i'm at -29deg. Timing advance is +29deg. What is it supposed to be?
Any relation to the CAM retard which is at -2.8deg at idle.. Don't know at 1200 rpm cuz truck will die if touch throttle? Just wondering if I have timing issue also.

The computer has put 29 degrees of spark advance into the command for the ignition module.

Seems about right to me, depending on the conditions the engine was running at the time.

-29 degrees and 29 degrees of advance are the same thing--the spark is firing 29 degrees ahead of TDC.

NO relation at all to the "cam retard" figure of 2.8 degrees.

 

[smokymtn65]

@mehcs did you get this resolved?

 

[mehcs]

@mehcs did you get this resolved?

Good day! Not sure yet. Since I had the intake leak… again… I tore it down and started over.

Getting pretty good at the tear down…

I set the lower intake and used the rubber end seals that everyone say not to use. I dunno, they seem to fit nicely and dabbed the corners with RTV per Felpro instructions.

I also ran a tap thru lower intake threads to clean and die on the bolts. Which I didn’t do last time.

I travel for work so hoping to get her back together this weekend.

I will definitely report back though.

 

[mehcs]

Good day! Not sure yet. Since I had the intake leak… again… I tore it down and started over.

Getting pretty good at the tear down…

I set the lower intake and used the rubber end seals that everyone say not to use. I dunno, they seem to fit nicely and dabbed the corners with RTV per Felpro instructions.

I also ran a tap thru lower intake threads to clean and die on the bolts. Which I didn’t do last time.

I travel for work so hoping to get her back together this weekend.

I will definitely report back though.

I’m considering testing the injectors for leaks prior to putting the Plenum back on by jumping the fuel pump. I’d like to physically see how they’re spraying for peace of mind. I saw a YouTube video on this but curious if others have done this.

 

[RichLo]

I’m considering testing the injectors for leaks prior to putting the Plenum back on by jumping the fuel pump. I’d like to physically see how they’re spraying for peace of mind. I saw a YouTube video on this but curious if others have done this.

Since they are brand new they should have been flow-tested and leak tested at 5-0 prior to packaging and shipment. Injector flow testers have come down in price a lot and you may be surprised how many places locally can hook them up and check them. Try parts stores first, if they dont have that setup, they should know somewhere that does.