Knock Problem

[84HAGN]

Ok guy/gals got the ride going and the fuel pressure set at 43 line off and went down the road knock gauge pegged into the red
backed off came to a stop and tried again knock gauge went to first green and stayed there next time went to pull out into traffic mashed throttle and knock into red again seems to be intermittenly going to red some time will pull good and others knock goes to red noticed black smoke out the exhaust yesterday along with the knock in red could I have to much fuel running turbo tweak at 17lbs on pump gas 93 octane
see sig for mods
Thanks

 

[SLOW_85]

Link

http://www.geocities.com/rad87gn/tech/knocklist.html
Check out the list.

 

[BRAD_PADGETT]

I had the same type of problem last week. In my case it was the MAF. I had an after market one which did not work. In my case-I was getting knock with 12lbs boost and alky injection. I installed an original 86/87 MAF and knock is all gone. Time to increase boost. Rebuilt or after market MAFs do not work. The LS1 conversion does. Just a thought. Brad

 

[SLOW_85]

I had the same type of problem last week. In my case it was the MAF. I had an after market one which did not work. In my case-I was getting knock with 12lbs boost and alky injection. I installed an original 86/87 MAF and knock is all gone. Time to increase boost. Rebuilt or after market MAFs do not work. The LS1 conversion does. Just a thought. Brad

I've had good luck with the Tomco units.
Don't think they are available anymore.
The LT1 / LS1 maf and translator is a good route to go.
Worth the money.
Always helps to have some kind of scan tool to monitor sensor readings.

 

[84HAGN]

Thanks guys was thinking about MAF still got the orginal 84 on there
I got Turbo LInk just got to get it up and running damn laptop batteries

 

[SLOW_85]

Ooops!
Was going to ask if you had the 87 ecm.
T-Link would give you some data.
Might think about a invertor, that's what I run my laptop with.

 

[SLOW_85]

Ooops!
Was going to ask if you had the 87 ecm.
T-Link would give you some data.
Might think about a invertor, that's what I run my laptop with.

Re read your mods, says you have the 87 ecm.
With the 84 maf prolly will run rich. Different calibrations.
Is your chip made for an 87 ecm with 84 maf?

 

[BRAD_PADGETT]

Let me give you some advice-The 84/85 MAF does not work with an 86/87 ECM. I have already replaced the 84/84 ignition system as well as the 84/85 MAF. The 84/85 MAF simply doesen't work on an 87ECM. Just a few thoughts. Brad

 

[BRAD_PADGETT]

Slow85- I have a Tomco unit from Postons which is for an 84-87 Gn. It only works for stock turbo boost levels at 10ibs. If you go higher like I am (12lbs boost and going to 20) the unit is a piece of junk. The original 86/87 MAF are the way to go and I am goto buy my second spare MAF soon. The only alternative is to go with an LS1 with translator=$$$$$Brad

 

[SLOW_85]

Well
Like I said I have 2 or 3 Tomco's and they worked great.
Run 22#'s boost no prob.
I also have a few original 87 maf's.
I run the LT1 and translator.
That's the prob with the remanufactured maf's, some are good, some not.
Not trying to start any arguments. :biggrin:

 

[84HAGN]

Thanks guys going to change maf next week will keep you posted

 

[boostmaster]

Number one overlooked problem for knock @ low boost = maf.

1- Tomco mafs do work, I have used them with success.
2- 84-85 maf will work with the later ecm, I am currently using one. Idles smooth and no ill effects on boost. The fuel curve will be slightly leaner.