type 4 motor

[GARRICK.CLARK]

Hi Guys ,I have made some changes over the past few months
Fitted the new fuel pump.
check valved the boost port on the fuel reg
same with the retard on the dizzy.
I had to drill a tiny hole on each nylon pipe below each one way valve to release boost pressure. Seems to work ok.
moved the turbo higher up to get the oil out pipe vertical.
fitted an oil restrictor to the turbo oil inlet.
Cant drive it yet, Roads are bad.
This back firing that I cant seem to sort out.
On A draw through the inlet manifold will always have a fuel mist in it. On boost/higher revs I think I'm getting a plug firing when 1 or more inlet valve is slightly open. I believe this is what's happening with my motor as the blue silicone hose that links the air filter to the carb inlet is stained black.
So is it just down to timing and or a lean backfire.

[Clonebug]

Not trying to be an ass but.......

It's a little difficult to help you when you start all these new threads. No one knows what engine combo you have anymore and it would take too much time to search through all your posts to find the relevant info.
You should stick to posting on your build page and then we can easily page back and refresh ourselves......at least it would help me.
All I can remember on your build is that you had trouble with a blow through system and then swapped to a draw through setup. Now you are having trouble again.

Most backfiring is caused by either ignition problems or mixture problems.

You should start by double checking that your ignition advance is correct on your degree wheel and if you have EFI then you need to confirm that the ECU is putting out the same as what is on the wheel.

Mixture needs to be adjusted and there really is no reason to have a turbo setup without a AFR gauge, It really makes a difference and can eliminate many questions.
There are many on the market and most are $149.00- $250.00.

If you don't have one I suggest getting one.......

[Piledriver]

A WBO2 is a LOT cheaper than a new engine.
With any turbo install that is literally a bet you are making without a WBO2.
Without one, you are only guessing on your tune.
Reading plugs really doesn't work with modern fuels.
(It never really did work compared to any modern WBO2)

[GARRICK.CLARK]

Yeah your right guys , it is getting a bit confusing .

I do have a PLX wideband fitted to this motor.
I'm setting the idle timing at 14-16.
Gunna limit the mech advance to 30
The retard canister will drop it back to 23.
If I set the timing as above and it still bangs then its not the timing is it.
Gunna get a mate to drive behind me at night to double check were the bangs are from.

[Clonebug]

I would set idle mixture at about 12.5-12.8:1 and see if that helps....
You have a long way for the fuel to go and need extra fuel at startup and idle

[GARRICK.CLARK]

Ok I'll set it at 12.8.1 at idle.
One thing I looked at today was the spark.
I'm using petronix 3 and the matching coil.
The spark is big, with a big crack sound. But the spark is ORANGE. From what I'm reading that's a weak spark that causes hi speed miss firing. I this correct.

[GARRICK.CLARK]

Well. I fixed the orange spark at the plugs, I opened the plug gap to make the coil work harder.

[Piledriver]

Too large of a plug gap can cause the spark to "blow out" under boost.
A lot of folks run a narrow plug gap to prevent that.

Also---Make sure your ignition is getting full power:
I always recommend a simple mod, running it off an engine compartment located fused relay powered directly from the alternator or starter main power cable, using the usually unfused and krispy fried factory wire only to control the relay.

On several vehicles I have had or worked on over the years, I have seen as low as 7v on a stock ign power wire with the engine running and alternator putting out 13v+, 8-9v is typical. Measure yours going into the coil.

[GARRICK.CLARK]

Thanks Pile. i'll be back.

[Buggsy]

Check your rotor phasing. The rotor may be to close to the next terminal instead of the correct terminal when spark occurs. This could be due to the Pertronix not being positioned correctly. If that is OK, I'd say your centrifugal advance is to much. Limit to 4 to 6 degrees. There shouldn't be more than that between the initial timing and full timing on a turbo engine. Get that squared away and we'll talk about setting initial timing and the vacuum advance. And yes, you should be running at least 12 to 1 AFR measured with a wide band sensor while in boost.

[Piledriver]

Rotor phasing.... Yup. Distributors have their limitations.

I found a great use for 009 distributors, other than as paperweights or tire chocks...
Provides an excellent trigger signal for a proper programmable ignition setup with LS2 coils...
There's some TIG'd in steel filler between two of those teeth for a "missing" tooth wheel.
(worked better than one filed out with the sensor I used)
The center tube is 3/8" hobby tubing, centered and fixed to the shaft with some orings.
The wheel was originally a $10 steel spur gear for a gas powered RC truck.

With the sensor I used the 36-2 I'm currently using works fine past 14K RPM actual shaft speed (on an MS3)
(That's as fast as the die grinder would do)

[GARRICK.CLARK]

That's pretty cool stuff there Pile. Beyond my capabilities at the moment.

Buggsy, you might be on to something here. How do I check if the petronix module is positioned right. It only seems to screw down on the plate in 1 position. How do I check the rotor is not too close 2 the next cap spark terminal, Get one of those cheap clear caps maybe and look what the spark is doing.
So if I have this right 14-30 timing is a bad idea.
I should limit the centrifugal to have 4-6 degree of range only, like limit the weights movement with limiting screws.
That would mean i'd have to set initial to some were around 22, and not use boost retard.

[Clonebug]

I would set initial at 8-12 degrees and then limit total to 30.

That should be in the range of the 009 anyways.

Use the msd to limit your on boost advance. Just do the standard advance drop most do for turbo boost and adjust as needed.
That should fix your rotor phasing too.

[Buggsy]

From the Pertronix instructions:
Note: Depending on which ignition rotor you have, you might have to remove some material from the bottom of the rotor so it will seat properly onto the distributor shaft. If not, it will spin freely on the shaft. If you have to remove some material from the ignition rotor, we found the easiest way to get a good flat surface was to carefully use of a bench grinder, taking off just a bit at a time. You can also use a flat file or a Dremel tool. Usually, if an ignition rotor needs to be modified in this way it require the removal of around 1/16-1/8" of material from the bottom of the rotor.
In other words, make sure the tab inside the rotor is fully engaged in the slot in the distributor shaft. You shouldn't be able to turn the rotor by hand. (except for the centrifugal advance motion against the springs)
I had to take an eighth inch off the bottom of my rotor. I'll get back to you on the initial advance.

[Buggsy]

So I got a chance to read through some of this thread, and first of all, I am amazed how patient and kind Piledriver and Clonebug have been to you. You should send them a gift card or something.
Some things jump out at me, and some info is missing, unless I didn't catch it.
You keep trying to run over 7 psi boost, and it pings. Stop doing that. You have no intercooler, and no water injection. Half a bar is all your going to get with your current set-up at least until it is fine tuned. Even then, 9 psi is about tops, which can be a lot of fun if the car runs correctly.
No where did I see what octane fuel your running. Without 93 octane, 92 octane, or E85, available to you, you have no business turbocharging this engine with carburetors.
I also didn't see what compression ratio your engine has, or what camshaft your using. Did I miss it?
Lastly, and most importantly, it sounds like your sending manifold vacuum to your distributor. That is not correct. Using a dual can distributor with boost requires ported vacuum. I don't know if Dells have ported vacuum channels cast into them. If not, then you have to abandon the whole dual can distributor idea. Do some studying and get a thorough understanding of the difference between ported, manifold, and venturi vacuum, and how they are used to send signals to operate distributors.
I have been using this system since 2001, and it works very well if done correctly. I have another car with a Megasquirt, and it also works very well.