ultimate chip user's,knock light flickers intermittently

[sabredog]

hey guys. I just got my Ultimate chip installed in my truck and on moderate acceleration,8-10 psi boost, my knock light will flicker and go out, esp. during gear changes.possible false knock like I've seen on many GN's ? Anyone with experience with this chip for stock truck with cold air and exhaust.The chip is on the lowest setting T115.
Thanks, John

 

[turbodig]

Re: ultimate chip user's,knock light flickers intermittently

hey guys. I just got my Ultimate chip installed in my truck and on moderate acceleration,8-10 psi boost, my knock light will flicker and go out, esp. during gear changes.possible false knock like I've seen on many GN's ? Anyone with experience with this chip for stock truck with cold air and exhaust.The chip is on the lowest setting T115.
Thanks, John

It's very likely (like 98%) that it's real knock. A scan tool will tell you for sure.

 

[sabredog]

Re: ultimate chip user's,knock light flickers intermittently

Hey Dig,
What would cause detonation at this low of a boost level/timing. I run good quality fuel, 93.The truck has new ur5 plugs, taylor wires, fuel filter, pcv valves, cap/rotor, operating new johnson intercooler pump, etc.I have also seen this knock light come on,flicker, just off idle pulling into my garage, no boost. Seems strange.While driving giving the car moderate acceleration, not wot,the light will flicker on intermittently.
Thanks for answering

 

[sabredog]

Re: ultimate chip user's,knock light flickers intermittently

I just got done driving the truck with a tech 1 attached using datalist.The results were yess it's showing knock on the scan tool. At between 6-7 lbs. of boost it showed 2-5 degrees of knock.the scan tool showed me basic info also like .56 tps voltage at idle and 24 degrees of timing .Can someone please lead me in the right direction to diagnosing this.I'm familiar with turbobuicks ,but new to these trucks.airm fuel ratio at cold idle was 10.1. What could cause this at such low boost levels?
Thanks

 

[turbodig]

Re: ultimate chip user's,knock light flickers intermittently

Hey Dig,
What would cause detonation at this low of a boost level/timing. I run good quality fuel, 93.The truck has new ur5 plugs, taylor wires, fuel filter, pcv valves, cap/rotor, operating new johnson intercooler pump, etc.I have also seen this knock light come on,flicker, just off idle pulling into my garage, no boost. Seems strange.While driving giving the car moderate acceleration, not wot,the light will flicker on intermittently.
Thanks for answering

Chip calibration.

T1-15 isn't as mild as most would think. Also, just because it's on t1-15 doesn't mean the fueling is calibrated properly.

"Good quality fuel" is a crapshoot. Locally, I have 93 octane that's garbage, 92 that's ok, and some 91 that is actually better than the 93. Also, 92 at one station isn't the same as 92 at another.

I've had a number of trucks that needed to have lots of timing pulled (back to levels even less than the stock chip) before they would stop knocking on the locally available fuel. Splash some race gas in, and the problem goes away.

There was virtually no margin in the original stock cal for marginal fuel. The kicker is that unless you're running dedicated race gas, you have no real idea what quality of fuel you're really getting.

Try the following:

Go to a home improvement store, get 2 gallons of xylene paint thinner. Put it in your tank with a full tank of gas.

If your knock goes away, you pretty much know it was real. (Octane doesn't fix acoustic problems)

If the problem remains, then you'll have to look for loose/clunking objects in the engine compartment. Common ones are broken motor mounts, fuel lines tapping against the trans, loose downpipe/exhaust, sometimes even loose suspension parts (although, the bang has to be pretty loud there).

 

[turbodig]

Re: ultimate chip user's,knock light flickers intermittently

.I'm familiar with turbobuicks ,but new to these trucks.airm fuel ratio at cold idle was 10.1. What could cause this at such low boost levels?
Thanks

Chip calibration.

The air-fuel ratio parameter is a commanded value, not a real one. You'd need a wide-band o2 to see real AFR.

 

[sabredog]

Re: ultimate chip user's,knock light flickers intermittently

I'll pick up some xylene and get back with a response. Would it be benificial to retard the base timing from 10 degrees to 6 ? What is considered the most allowable knock retard. I know ideally 0 degrees,but with buicks it was between 0-5 degress of knock retard on the shift.
Thanks again for the help with diagnosis
John

 

[sabredog]

Re: ultimate chip user's,knock light flickers intermittently

Being a novice, I just found that the base timing is 0, not 10 .I have not yet verified my base timing, but I will.I also read about ignition modules going bad in these trucks, Is this true?Are ur5 ngk's ok in a mostly stock truck? Still testing! My truck also has a roughness to the idle and slight roughness on initial take off, idle speed is 725 rpm's.

 

[turbodig]

Re: ultimate chip user's,knock light flickers intermittently

What is considered the most allowable knock retard. I know ideally 0 degrees,but with buicks it was between 0-5 degress of knock retard on the shift.
John

That's a bit like saying "How many times can I hit my pistons with a big hammer before they break?"

Personally, I think the answer is 0. I've let 1-3 degrees pass. 4 is marginal. 5-6, you've got something that needs fixing. More than that, you better stay off the throttle until you figured out what's going on.

From personal experience... I never let mine get above 6 degrees, typical was 0 with the occasional 2-3 on a shift. It lasted 11 years that way before taking out a ring land on the #2 and #3 piston.

Moral of this story... anyone who puts an aftermarket chip of any kind in a SyTy and doesn't have a scan tool to watch knock, *will* end up replacing a motor shortly.

You're ahead of the game since you have a Tech1. It's not ideal, since you can't log a whole run, but it beats not having any information.

 

[sabredog]

Re: ultimate chip user's,knock light flickers intermittently

Today I verified my base timing was "0". I did find a local paint store that sells xylene, and I will purchase some tomarrow. I also bought a new AC Delco, coil and ignition module. Would it be a good idea to try and find one of the higher boost/lower timng settings on my chip to do a 5-6 lb. boost test, thus simulating lower timing than the t115 setting. Good idea ?

 

[Syclone#2960]

Re: ultimate chip user's,knock light flickers intermittently

Sabredog-

The T1-15 setting will activate the EGR system and cause extra heat to enter the intake. Try running on T1-16 instead. I'm not saying this will cure your problem. Only cool the air a little better to help avoid detonation from hotter air.
Check your motor mount on the driver's side to see id it broken. Could be causing the knock during shifts.:2cents:

 

[turbodig]

Re: ultimate chip user's,knock light flickers intermittently

Today I verified my base timing was "0". I did find a local paint store that sells xylene, and I will purchase some tomarrow. I also bought a new AC Delco, coil and ignition module. Would it be a good idea to try and find one of the higher boost/lower timng settings on my chip to do a 5-6 lb. boost test, thus simulating lower timing than the t115 setting. Good idea ?

Doesn't work that way. The T1 settings all have the lowest timing, and the timing curve is the same regardless of what boost level you're at.

Another thing that might be happening... you may be getting boost spikes at the shift points.
The ultimates weren't the best at controlling boost... it was kinda up and down throughout the run. This could be causing knock at the shift points. Xylene would likely reduce or eliminate this, unless it's a really big spike.

I've had to retune the boost control on several ultimates. Helps quite a bit.

 

[sabredog]

Re: ultimate chip user's,knock light flickers intermittently

I have tried the t116 setting to no avail. I will check the motor mount though. The truck does shake alot at idle. Thanks Bruce.

 

[sabredog]

Re: ultimate chip user's,knock light flickers intermittently

Here's the latest in the quest for no knock. I installed the new GM coil, it did not help at all. Then I added 2 gallons of xylene to a full tank of 93 fuel. Now the light did stay out until around 9-10 psi of boost on setting t116. I again immediatly got off the gas. I still have an ignition/dist. module to install and see if that does anything. The next thing I want to do is give it a good "top engine cleaning'. tHE ORIGINAL OWNER WAS AN OLDER GUY THAT GOT ALL HIS WORK DONE AT A DEALER AND HAD ALL HIS RECORDS.Sorry for the caps. But his records show at no time did he ever have this done.I know this engine has some blow by and the pcv does suck alot of oil vapor back into the motor so it will be interesting to see how much this helps. There may still be some false knock due to the fact that I have seen some knock flashes with no boost at all.
Please keep the suggestions coming. Thanks

 

[sabredog]

Re: ultimate chip user's,knock light flickers intermittently

I ran 2 cans of top engine cleaner through the engine and changed the oil. I drove the car last night and got on it.I got a flicker on the shift and at wide open saw the light come on again at 16 psi.I again immediately got out of it. I think I am going to run 1 more can through it of top engine cleaner. Does this car and the obviously poor fuel around here look like a good candidate for alky injection? Thanks for the replys.

 

[Syclone#2960]

Re: ultimate chip user's,knock light flickers intermittently

Alky was the by far the best mod I ever did. Is your motor completely stock?

 

[sabredog]

Re: ultimate chip user's,knock light flickers intermittently

Yes it is . 63000 miles on it, 93' model.cold air kit, hi volume intercooler pump and exhaust.On my GN, i ran an SMC Alky kit and on my 89 TTA, I used Alkycontrol. Both nice kits.

 

[Syclone#2960]

Re: ultimate chip user's,knock light flickers intermittently

I was having similar issues with my setup as well. I replaced the knock sensor with a new one and the problem went away. I installed the new one hand tight. GM calls for 14lbs. but I don't have a short torque wrench. It's worth a shot. The best way to get to it is through the passenger side by removing the spark plug wires from the cap.

HTH

 

[The Devils Own Chariot]

Re: ultimate chip user's,knock light flickers intermittently

I know this post is a year old. I just feel the need to comment on it.
I have an ultimate with a knock light. It’s pointless to even pay attention to it. It flashes over anything. I close the door on the truck it flashes. I have a noisy lifter that makes it flash, I turn the key just so the radio turns on and the light flashes. It’s supposedly tied to the knock sensor but it sure is sensitive.
Go off of data master and how much timing is being pulled. A good wide band is always best. I have an ETG that can reassure me that I'm not running leaner than normal but I would never tune off one. Gas does vary and that makes a difference in how it runs.
I also notice I get less timing pulled with more aggressive timing than with less timing on the same boost level. I think its false knock for the most part. I once ran my stock truck on 18psi with just 93 octane, four bottles of octane booster, t2 timing, and fuel pressure up to 52 lbs. I had no timing being pulled hardly at all. It seemed to vary depending on the temperature of the day. That makes sense though.
My conclusion is I think knock lights are stupid. It maybe a good thing if you’re going down the drag strip and you see it going crazy and let off the gas.