Knock with an 84 ECM?

[84T-typeMike]

I use an OTC 2000.All I get is a YES/NO for knock.How am I supposed to turn up the boost if I can't tell if there is spark retard?My O2 volts stay at .840 steady at WOT.I think that tells me I can add more boost to get the number down to .770-.800 but at the same time as the .840 the knock YES/NO reading says NO then 1/2 sec later YES then 1/2 sec later NO then 1/2 sec later YES etc........What am I to do????????????. :joint:

[ledzeppac]

buy a scanmaster 2.0

[84T-typeMike]

If I am correct scanmaster will NOT work on the "Hot Air" cars.Don't know why,but I guess I am asking if you can have knock when the O2 is .840?Does knock only happen when you are getting too lean?Can a person use just the O2 voltage at WOT to tune the car and be somewhat safe about it?For example:My O2 reading is .900 when I first stomp it.The O2 voltage drops to a steady .840 from .900.So If I turned up the boost the .840 should drop.So lets say it goes down to .720,I can either drop boost OR turn up the fuel pressure to get it back to a safe number.Is this correct? IF this is correct can you keep adjusting boost then fuel then boost as long as the O2 voltage is at a "safe" number.By the way,is there a safe number?Thanks!Mike

[turbo6x2]

I thought the scan master read the 02 a little high compared to the direct scan or turbo link. I thought .8000 was ideal for the reading on this? If so you are really close. Do you have a fuel pressure reading and how much boost you are running currently? The cars actually respond better to an egt reading as far as tuning. O2 readings are a guide line but I know a constant exhaust temp is more consistant and more accurate. If I were to recommend anything I'd suggest the upgrade to the 86-87 ecm for program ability and more functional scan numbers and tools available. The cars generally run better with the upgrade as well. Just a thought.

[SLOW_85]

Yes
You can get knock from being to rich.Hard to tune without some way to monitor the car.
What boost you trying to run? What fuel pressure?
What octane fuel? What mods,if any? Getting knock on shifts?
Usually car will be rich on launch and lean out on top end.

[84T-typeMike]

Ok Thanks guys!Here is where I am at.My car has only a few things done to it.Compression on all 6 cylinders is either 134 or 130 pounds.Car runs good!NEW Delphi 30 pph injectors and harness.NEW stock turbo.Idles around 650, 675 RPM in gear.850, 900 in park.IAC is 10-20,TPS is .44 and 4.68 at WOT.MAF is 6,7 gps at idle, around 170 at WOT.BLM is 105 or higher and INT usually hangs around 128.Car WILL PASS emissions testing.VERY little soot in tailpipe.I always use 92-93 octane.Fuel pressure is set at 38 pounds line off and drops to 28-30 with line on.I just got an ADJ. fuel reg.It is NOT on car yet.Fuel pressure rises to about 55 pounds at WOT.I am running 13 Pounds boost according to my NEW VDO vac/boost gauge.AT this setting the stock gauge in the dash is RED LIGHTING.I tried a few passes at 10 pounds boost and 13 pounds boost.NO CHANGE. SAME MPH gain of 17 MPH from the 1/8 to the 1/4 at both 10 and 13. I don't hear anything that would concern me from the engine on any pass.SEEMS to run GOOD!I just don't know how much boost MAX. I can run without being in danger.I want to try 15 but not sure it will change anything as the 10 to 13 didn't make a difference.The car runs 15.8 in the 1/4 now.Shooting for 14.0 in the 1/4. DID I leave anything out?Please HELP!Thanks,Mike

[racemybuick]

What mods do you have? I would suggest that you get a good cat back exhaust system, along with the usual, K&N, ADJ FPR, 160 stat, water temp guage, Boost gauge, Tach, oil pressure, and a knock guage too. Upgrade the ECM and get the Direct Scan scan tool. Everyone I know who has used it has not complained about it. The OTC will also work better with the new ECM. The ECM part number you are looking for is:1227148, and can come from any distributorless GM car from that year, like the grand am's, the Park ave's, lesabre's, and so on. Just make sure the number on the ECM is 1227148. Also, you will need a chip custom burnt for you (Jim Testa), and just by tuning your car well, and running a little higher octane, you can pull that 14 easy. You may even break into those 13's!!!

Good luck

John

[turbo6x2]

Is the fuel pump stock or upgraded?

[84T-typeMike]

Fuel pump is stock,The 20 year old version.I think,well its at least 9 years old assuming it was changed the day before I bought it!I will definitely get a Walbro 307 ASAP with a new sock.AS well as the "hotwire".ONLY a few MODS left that I want to do right now.Fuel pump,hotwire,Adj. FPR,Hooker 2 1/2 Cat back.Thats all I can think of till I pull engine and "Do it up again".Then by next season Probably the 86/87 conversion.When you guys AND gals say a "good tune" What exactly does that mean?Make sure all the numbers are right or what?Thanks! :top:

[turbo6x2]

I would strongly urge you upgrade this before doing anymore racing. The stock pump is a joke at best. You'd be a lot safer with a 340 Walbro or one of Red's 307 (I believe that's what it's called) Fuel pumps. You are risking lean conditions with the stocker. Lean means bad bad things...I think if you're planning to do that you are on the right track.