Spark rattle with new alky chip....

[Steve V]

I took advantage of the sale and got an alky extendar chip. Before I had a regular extendar chip. I was getting some transitional knock. None at WOT. I also have that stupid surge and the tornado helped but didn't cure it.

I put my new alky chip in and I got into it twice and both times I got major spark rattle on the ramp up to full boost. No knock on scanmaster and at WOT to rattle/knock. I am not doing that agin for fear of popping my headgaskets(if they aren't hurt already).

My alky was about 3/4's up. I have not messed with any of the settings in the box. TE44,60 injectors,duttneck IC,25 lbs of boost. Motor has 1k since freshening,new plugs,wires,all sensors are good,no issues anywhere other than this spark rattle.

Any ideas?

 

[Steve V]

After searching and reading....I am going to increase the intital to 12:30-1 o clock. The alky chip should have a more agressive ramp up in timing and that would be the cause of my mad pinging.....or atleast I think.

 

[Razor]

How fast is this car? 10, 11, 12 ?'s

You may want to look how you have your translator curved. If you have it pulling fuel out at idle.. and WOT.. the whole curve is going to be lean. Vs.. adding fuel at idle and WOT.

Also make sure the "LIMITER" is set to off in the dip switches.

Lastly make sure the alky kit is priming correctly.. use the test button and make sure the engine stumbles before going WOT.

 

[Steve V]

Low 12 sec car, ?I have no fuel pulling out at idle or WOT. Switches are set correctly. Kit primes correctly.

 

[Razor]

If you roll into the pedal.. not MASH it. does it also rattle? Or only when you stand on it?

What are your BL numbers on your scanmaster? Are they +-10 from 128 at idles and cruising?

 

[Steve V]

No rattle from a roll(just flutter but I can drive through it),only a mash.:biggrin: BLM's are in the low 130's everywhere accept idle,it's 140 ish. I have n't found any vaccum leaks,exhaust leaks etc. Car runs great.

 

[Steve V]

Update...turned both up some and it still does it,but it's a little less...I think.
Idle BLMS are 137,no knock/ping at WOT. NGK UR5 plugs gapped at .033.

 

[Razor]

If all the BLM's are higher than 128(cruise, idle, decel, accell) then the fuel pressure needs to be bumped up.

You want some BL numbers higher than 128 and some lower... whereas 128 is the centerpoint. If you have a vacuum leak, it typically shows in the idle BL..

Remember above 128 the computer is adding fuel.. meaning your fuel pressure is not enough.

This i've seen countless times when someone trusts a rail mounted guage for fuel pressure adjustments.

Adding fuel throughthe regulator should bring down the BL numbers.. and at the same time increase delivery of fuel throughout all the range when going into boost. If your motor is Lean going into boost, it will rattle.

 

[Steve V]

I wanted to update this thread....I played with fuel pressure a bit. I have an old Kenne Bell hood mounted guage. It reads abount 43psi. Turned it up to 45-46,no change. The BLMs did come down slightly. Raised it to 48 and everything stayed about the same. Still had rattle,none at WOT.

After some research I saw that I increased the turn on instead of lowering it. Found a pics of the stock settings in the box and lowered the turn on just a bit,increased the gain a bit and wholla no ping. Still has that stupid 44 compressor surge at 5-15psi,but it runs great if you stab it. No traction:biggrin: Pulls like a train from 45 to...when my balls are in my throat and I lift

 

[QUIP'6']

Update...turned both up some and it still does it,but it's a little less...I think.
Idle BLMS are 137,no knock/ping at WOT. NGK UR5 plugs gapped at .033.

it may not be your problem but i ran the ngk ur5's and i got the same rattle . then i went back to ac 43's and it is gone

 

[Steve V]

No offense,but I have read nothing but good things about those plugs on both sites. I don't believe they are the issue.anybody else had a similar result,please chime in.

 

[Razor]

Sometimes what works for someone doesnt work for someone else. Be glad when you find the demon your trying to exorcise.

I dont agree with using the alky to pad a fueling issue in the tuneup.. as the chip/maf should be taking care of this. But at least its working for you.

 

[Steve V]

Another update..

Ok still have something going on here. It's kind of intermitant. Sometimes it rattles sometimes it doesn't. I figure lets start over. Turn alky off,lower boost,put in non alky chip. Fpress guage back on the hood(looks like ****). Got a new delco O2 sensor.

Drove out to my brothers house. Relearned fuel tables,started to get into it. No issues at all,15-16 psi. Base fuel pressure 45,wot 60,blms are great 129 at idle and some above 128,but most are about 120-125. Car runs really good. Smooth coming up on boost etc(I did remove the tornado since there no surge at low boost).

I'll be honest,I was starting to suspect the pump. I had some ping when it was stock after I 1st bought it and it had just a chip and a new pump. Dismissed it back then. Then last fall after the rebuild I was getting knock and ping. I swapped ECM's and problem went away. I had issues on really warm days. Today is not hot,but warm and muggy. I've been reading all these pump failures lately has me concerned. I was starting to think that the alky was covering a weak pump,psi is good but volume maynot be enough in the mid range and the alky can't cover it up until it gets going, That would explain lack of WOT issue.

I am going to leave alone and drive it to work a couple times like this and see if it will ping. If not maybe next Sat I'll up the boost and turn on the alky.

I just hope all this experimenting doesn't cost me a motor.

 

[Razor]

Turn the alky on.. car should be smooth as a silk with the alky on at 15 PSI boost. Maybe a tad rich.. but not enough to cuase a drivability issue. And yes do this with your street chip.

If its not.. then something else is going on.

HTH

 

[Steve V]

I will try that on the way to work tommorrow.

 

[Steve V]

Turned on alky no problems car feels the same,still at 15-16psi. Now turn up the boost or change chips? I also need to return the settings in the box to stock.

 

[Alky V6]

Just curious. When the engine was rebuilt, what compression ratio did they set it up with? Did they physically cc everything to double check?

Did they have to surface the deck and/or heads? If so, do you know how much they cut?

What thickness head gasket?

Custom pistons or off the shelf?

Those NGK plugs. They're not platinum are they?

I hope you don't mind answering these questions. They probably have nothing to do with your problem. I'm just curious.

 

[Steve V]

Don,no I don't mind. I did all the work and everything is standard. Stock thickness gaskets,stock pistions. Nothing taken off the deck or heads. Motor was in very good shape,as a matter of fact I reused the stock cam and lifters. Cars runs great with 16-18 psi boost.

NGK UR5 plugs are not platnuim. There are several Buicks owners using them here with no issues. I did an extensive search.:wink:

 

[Razor]

Turned on alky no problems car feels the same,still at 15-16psi. Now turn up the boost or change chips? I also need to return the settings in the box to stock.

Now that you have a car running predictably.. start upping the boost..

If you change chips.. your back to square on and start just like you did at low boost.

 

[Steve V]

I already changed chips before I read your post. Car still runs great but my idle blm is 138 with alky chip and it was 129 with the street chip. I will reinstall the street chip and up the boost a bit and see what happens.