Build Thread Enola- Finishing touches

#2,281
The mounts are new, and the motor does not have the bad mount "shake" that usually accompanies them. I can hear this noise from both sides of the engine above it and from under the car.... The fresh oil change is already sullied with a fuel smell and has some combustion smell to it.

I think i finally broke it, In my mind the engine is ****. The main question now is what is causing the bucking and intake popping could a damaged piston or broken ring land cause that???
 
#2,282
That noise doesnt around good. I can't speculate what's wrong from the video.

I Just hope you figure it all out and it doesn't cost a lot to get it back together.

A broken ring land shouldnt cause that. Usually, the car will smoke or lose compression. Seems like it was a timing issue that caused whatever is going on now.
Wish you were closer... I've got a spare 302 that i know is good i'd give you, if it came to that.
 
#2,284
Noobz347 said:
What were your TPS(s) doing at the moment that started?
Click to expand...
Could you clarify what you mean?. If your taking about the bucking/popping....
The wife was driving the car, normal acceleration in second gear. Tps was around 45-50% making just under 1psi. Fuel here is always a non issue 12.7 AFR, the rpm is bouncing erratically during the bucking on the datalog from 2100 to 2600rpm.
I should also note there is a pressure spike in the manifold when this happens, spike anywhere from 8- 16 psi
 
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#2,287
a91what said:
Could you clarify what you mean?. If your taking about the bucking/popping....
The wife was driving the car, normal acceleration in second gear. Tps was around 45-50% making just under 1psi. Fuel here is always a non issue 12.7 AFR, the rpm is bouncing erratically during the bucking on the datalog from 2100 to 2600rpm.
I should also note there is a pressure spike in the manifold when this happens, spike anywhere from 8- 16 psi
Click to expand...


I'm wondering if there is some reference in your tune that is not taking collective TPS into account --or-- this is the spot where throttle resolution is being missed and possibly corresponds to the opening/closing of the secondary throttle body.

12.7 AFR seems rich as eff for 1 psi. Popping helps support that theory.

Every bucking issue I've encountered so far has come down to tuning.
 
#2,288
Noobz347 said:
I'm wondering if there is some reference in your tune that is not taking collective TPS into account --or-- this is the spot where throttle resolution is being missed and possibly corresponds to the opening/closing of the secondary throttle body.

12.7 AFR seems rich as eff for 1 psi. Popping helps support that theory.

Every bucking issue I've encountered so far has come down to tuning.
Click to expand...
No this is below the secondary TB opening, I see the tps enrichment in the log no issue there. 12.7 at 1psi is no issue at all it is in fact around the best mbt AFR for a NA car. Usually 12.5-13.1 makes best power near atmosphere pressure.
The bucking has always occurred at this rpm on me in first gear, whatever it is that is happening was less prevalent before yesterday and has gotten worse.
I changed the throttle configuration to try and alleviate the issue thinking it was a pressure surge problem. Obviously it didn't help.

Popping in the intake manifold is usually a lean condition

This isn't your usual bucking that I usually tune out this is very violent like the spark fires on the wrong cylinder
 
#2,290
Noobz347 said:
Another random thought:

Timing Tip-in
Click to expand...
Its all based on manifold pressure, when it occured this time the timing was only 24* due to manifold temps being near 200*

I do see that the intake temps went from 200* to 340* after the incident [engine stalled when she held the clutch in] this tells me that there was a fire in the intake manifold. :eek::eek::eek::eek::eek:

NOT GOOD

this is why i think there is a timing issue something had to ignite that fuel with the intake valve open over multiple engine cycles
 
#2,293
I think I am going to do the obvious stuff first, compression and leakdown test. If those pass then I will swap the coil packs and double check my wires are not cross firing. They do pass behind the intake manifold and run parallel.

If the engine is knocking after that.... well idk I think my wife will kill me if I try and fix it.

On another note wouldn't a bottom end noise be faster than what was in the video?
 
#2,297
Time to take the oil filter off and cut it open. Cheapest and easiest way to see if something let loose. If something metal is beating itself to death....it'll leave evidence in the filter " 9 times outta 10 ".

She has no say in what you do to fix it.... it happened on her watch. :shrug: That would be my story anyways o_O... guess that's why my wife won't drive my project cars.... unless she just thinks I'm a lousy mechanic when I've been drinkin'.

I tried to tell her that's when I do my best work.:cheers:
 
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#2,298
Well some new developments. Don't know if it has anything to do with the bucking and popping but....

I ran the car and got the knock when I got home, then removed the belt to help isolate the sound... except there was no longer a knock.
Put belt back on and the knock is back loud as ever, I went and got a piece of wood to use as a makeshift stethoscope. Sure enough I think the blower has begun to eat itself. Goes away with rpm but is loudest at the blower, then sheet metal intake I have on it likely amplified the sound.
While this sucks I at least have a starting point. Still does not explain the backfire though
 
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#2,300
That's better than a new engine. Explains alot. The backfire tried to back spin the blower....so everytime the backfire occured it blew up in the intake.....causing pressure to rise....that pressure rattled the blower.

Smh..... guess it's better than an engine. Depending on what exactly it is.... that thing can be rebuilt and ported.
 
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