I just installed direcct scan (I LOVE IT!!) but I have a quick question. that it doesent tell in the book, the knock sensor, it has #s but it doesent say what they mean, is it how many knocks?, how hard?, and could someone tell me what is exceptible? I made a pass and recorded it it said 28 the hole time, but during real time it shows less. thnx for your imput cya all later erock
Another quick question or 2 1 is the time slip info on ds accurate if I hook up? 2 my tps is set low36idle and 4.36 wot i will fix tomorrow do expect a difference? 3 last but MOST im portand I get a[[roxamatley 12 or so knock counts in a pass retarding the timing somtimes 5 degrees is this normal? or is it bad?
im running mostly stock eccept red93 chip xp pump and hotwire kit and adjustable reg set to 43 static modified mufflers no cat tnx
94 octain fuel knocks are usualy in 2nd and mostly 3rd and ofcourse in the shifts
WOW aren't I a pain in the %$@$#@ last thing i promis on the passes my o2 start at820's and drop emedieatly to mid and mostly low 7's even hit 6's I dont know if that is lean or not , it keeps reading rich the whole time
You should strive for no knocks, or maybe a _few_ knock counts during a pass. Perhaps one or two during a 2-3 shift or TCC lockup for instance. A few blips of retard may be tollerable, but constant retard or double digit retard means you need to do some tuning. Or start thinking about when you're going to replace the head gaskets you're about to blow.
Yes, a DS 'time slip' can be fairly accurate if you have a solid launch. But I wouldn't treat is as gospel.
"Rich" indication just means above stoichimetric, or about 450 mV. That does not mean its running 'too rich'. In fact, below about 750 mV at WOT usually means you are very lean. If you are in the low 700s or even 600s, you're leaning out too much to be safe.
There are two very useful items to look at in DirectScan regarding knock...
1. The "Knock Count" is simply the number of times the knock sensor has sent a pulse to the ECU. It starts at zero when you turn the ignition key on, and adds one count every time the knock sensor is triggered. On my car, the counter usually goes up about 2 or 3 points during the process of starting the car. I often get a ping or two when the transmission shifts, too.
2. The "Knock Retard" is the amount of spark advance that is being taken away by the computer because of knock indications. If you subtract the "knock retard" number from the "spark advance" number on the screen, the result is the actual delivered spark timing at that instant. There is an algorithm in the ECU that retards the spark timing depending on how rapidly the knock sensor is sending pulses (indicating spark knock events) to the computer. If you just get a single ping or two, the computer will only retard timing a little bit. If you get a series of several pings in a row, the computer will retard a lot of timing and reduce your boost level (depending on your chip). You will notice when this happens, because the car will slow down or even cough noticably. If you see this happening, tuning is required to prevent it! Too much knock will cause head gasket issues. I think 12 knock counts in a single 1/4-mile pass is too much, or at least it's too much for me! I try to tune my car so that I only see two or three knock counts (usually I get one count during each tranny shift).
On the O2 sensor readings - if you are running O2 sensor readings less than 700 millvolts during a 1/4-mile pass, you are running way too lean! With 94-octane gas, I try to keep my O2 readings between 790-810 millivolts. Others will go lower, but nobody tries to run in the low 700's or high 600's with pump gas. Running this lean causes very high temperatures/pressures and can blow head gaskets. Plus, running that lean makes knock a lot more likely. I would figure out what it takes to get those numbers back up to the high 700's at least. Of course, everything I just said assumes that your O2 sensor is healthy. If you have any doubt, replace it. It's cheap (less than $20) and a very useful tool for tuning if it's working properly.
Good Luck,
Mike
tnx Mike most Ive messed with already, I tryed bumping my tps I got it higher but it turns out it wasent set right, when i did that it seeemed better o2s were not bad until 3rd gear where it seems im running low on pressuer(fuel) the o2 will drop to low 70os and it starts to ping, so at that point I went to more fp. I went from 43static to 45 and it got a little better but I started getting drivabilety probs and turned it back but know I think it was the tps i had set it at .52idle and4.48 wot i htink the idle might have been a prob. I wonder if the tps will make a difference its now set at .44 idle and4.34 at wot witch i think is low I read where itsm sopossed to be ill put it there tomorrow and see. tnx for your help. Eric
Hi all, new to this board.
I own a '93 GMC Typhoon. I have been trying to get my knock counts reduced as well. It hasn't been easy. I have an aftermarket chip installed, when I removed it the knock went away. I put it back in and retarded the timing a few degrees, but did not like that way of trying to fix the problem.
I am a little confused about why I am getting this knock. I have the FPR running rich, O2's are in the 900's @ WOT, but my EGT gauge reads ~1100-1200* (probe is mounted on the downpipe). It is usually around that temp while driving on the freeway w/o getting into boost. And when I do get into boost, it goes up to 1250-1300*...does that seem hot???like I'm running lean. Anyway, I appreciate any help as I have had this situation for a while now. I am thinking I could have a bad injector, and would like to replace them. However, I don't want to just replace the injectors with the same size, because I have a TE44 that I would like to install. I would like to get a larger injector, but that would require a new chip (which hasn't been developed yet) or speedpro (which is too much $$ for me right now).
Anyway, I would rather get this running w/ very few knock counts. I would guess one solution would be to pull the chip, and go back to the stock chip & 2 bar map sensor for now. But wanted to get some opinions on it first.
Thanks much,
Scott
Sorry...this board is for Turbo Regal discussion only. And besides not being TR related, your question has nothing to do with the Direct Scan subject. Perhaps you should try www.syty.org.
If you can't get full range on your TPS, you may need to modify its mounting tabs slightly. This is mentioned in http://www.gnttype.org/techarea/maintenance/TPS.html
I can get the tps where it needs to be but it wouldent run right, so i thought I was to high @ idle, so I turned it back to its origenal settings (.36 and 4.36) and I got back the drivabilety but I nor any of the other gn guys here can figgure whats happining now. When I get into it usualy in 2nd gear the ignition system will (blip) just shut down then come right back on @ wot, my lights and radio etc. still work but on my direct scan all the sensors go to 0 and it goes to open loop even the batt. voltage reads 0( i checked the connecs, no prob there, eccept the iac still reads, thats about it I keep getting est errors, then eprom malfunction error and so on. Im guessing the ecm is hit but I dont know anyone that has seen this before I could yous your advise .... boy talk about your domino effect. tnx eric smith
you may have a wire connection problem.
Check the positive cable by the starter motor. There have been reports of frayed/loose connections, or bare wires hitting the frame and/or engine under hard acceleration (engine flex, worn engine mounts).
Check for loose or corroded ecm connections.
tnx steve thats a good answer. I will check that in the morning, because I am heading for red armstrongs place if that isint it, I need a few things and mabee he has seen this before ... anyway tnx it sounds possible. ill let ya know
eric smith
Eric, one thing I neglected to mention is, if, after this 'disturbance', you see all the ecm block-learns have been reset to 128 this is a sure sign of lost power to the ecm. There you would have proof of a power connection problem.
good luck.
tnx steve but it looks like the blm's stay normal everthing else goes to defaults. so I recorded while I unpluged the power and you were right the blm's go to 128 but not when I have my distubance. The onle thing I havent checked yet is trying to short the system and see what happens, but Im afraid of cooking somthing, so I just went and bought a new ecu, it will be in tomorrow and i'm also going to the track to I wont give the core up untill then well see tnx for the info it has came in handy so far ill let ya know what happens tomorrow cya eric smith
Eric, You might watch your direct scan connection also. I cleaned the protective coating to far back on the computer board and when I push the connector for the direct scan to far in it will do the same thing. It will reset the blm also. One thing I noticed is if I install the direct scan when the car is already running it will flutter the engine if it goes to far and under hard acceleration if the plug is to close it will have the same symptoms you are talking about. chuck
tnx chuck ill check it 1st thing in the moning. and bye the way after further evaluation I was wrong the blm's do reset to 128 when the event occers, I tell you guys I have went over the car with a fine tooth comb I can not find any sighn of corrosion or shorts or loose wires of any kind the only thing I do find is that when I pull the power wire to the ecu while it is running ( to record what happens to compare) after doing so it seems to go away for awhile, but the connection seems to be fine I cant get it to jolt or anything. Mabee its not a good connection and it becomes a problem at high rpm or under a heavy load "hence it seems to happen more at wot" I almost always get a est. code afterit happens ....again tnx chuck I will check in the morning....and last case sinario I'll have a new ecu tomorrow .....tnx everone for your help it seems as though there is not much left it could be , so it can't be much longer before I ( with the help you have given me ) finnaly get it cya Eric Smith
Eric,
the problem lies with grounding the the actual ribbon cable from the ecm to the DS box. I was told to wrap it in foil to sheild it from the ecm and tape it to the ecm to ground it. It didn't work so now I am going to try to have the wire shortened. I went nuts with this problem myself.
Car would cut out at wot or get a whole bunch of codes under normal driveing and run real crappy. I tried switching ecm's, new coil pack, iginition module, plugs, wires. I think its just this "interference" problem between DS and the ecm.
HTH
Chris
wow! Chris could you elaborate on exactly what to do or did you get it fixed or are you still working on it you can email me if you like I would like to talk to you if I could my email is erock1971@yahoo.com
Chris,
I don't see how it would ground or how aluminum foil would help seems it would ground it out, I know on mine that if I pull the connector out a little it runs fine and the direct scan reads fine. If you look at the board you will see if you clean the coating off to far the terminal go to thin leads and the connector would short out the leads. Maybe we have different problems but mine sounds the same as ERIC. I get like 10 err codes, ECM err, diode err, no sensor readings and others.
after more reveiw I would think Chuck to be correct on this I cant see that happening, mabee your and possible my connects need to be better. Thats somthing I'll try tomorrow. I didnt think the ecm to the ds connect could give me problems running because it is only supossed to be a read only system therefor not effecting the way the ecm performs ,,, but I could be wrong , therefor ill give it a shot tommorow eric smith
The aluminum foil trick is used as a "Faraday cage" to help shield the cable (it's not really grounding anything, per se). Induced currents from radio interference travel on the surface of the shielding to ground (instead of inducing a current in the actual cable wiring). That's why the ECM is in a steel box ... the enclosure prevents radio interference, AC hum, etc. from screwing with the ECM.
Funny side note, there was a documented case where certain models of Jettas/Golfs in California were having some wierd problems with the engine quitting suddenly at seemingly random times. Turns out, they had inadequate shielding of the electronics and when passing certain electric fields (high tension power lines, high powered radar (like for the airports, etc)) it'd kill the car! Some additional shielding/grounding solved the problem
Anyway, with an cable sticking out of the side of the ECM that connects directly to the motherboard, it can act as a big antenna for RFI and such if not properly shielded (make sure the cable you are using is a shielded one... they are more expensive, but might help). A car is a relatively "dirty" environment, and a loose spark plug wire arcing slightly can make all sorts of radio noise.
Well the foil thing did not do the trick as the problem still exists. Even if the laptop is not hooked up, as long as the cable is plugged into the ecm the problem is there. I have not resolved this but I don't have a working laptop right now though so I just unplugged DS from the ecm and rely on the scanmaster for now. Once I get the laptop working I'm gonna call Ken Chu and see if he can help me out.
There was a thread on this on Turbobuick.com which is where I was told to try the aluminum foil shield. Try searching on there. I'm not sure if it was lost when the site crashed though or if it was after that.
Interesting though, about removing too much of the coating on the pins though. I wonder if I had mine plugged in too far.
How do you get time slip info from ds2.1? Ididnt see that in the instructions.
It's KENT Chu ...
Chris try backing out the plug a little bit like chuck said I beleive it has fixed my problem. I purchased a new emc. but I didnt need to instal it after taking Chucks advise I havent had a prob yet...INFACT! hehe.. I drove all day then drove to the track where I completly smoked! my best et. before today I had a 13.42 and after tuning with the ds. and a couple of passes I ran a 13.008 @ 103 mph with street tires! mind you the only thing in this mostly stock 86 gn is red armstrong 93 street chip, adj, fuel reg, hot wire kit, cold air intake, some small tweeks but THATS IT! LESS THEN $300 BUCKS IN IT YET. I'm a happy man. It would have been nice to take home a 12 sec slip but ran out of time, I was about to crank the boost a little ( I was running about 18and a half psi that run though) this thing is creeping on the back door of my last drag car, and its my daily driver ... I know there are alot more out threre faster and daly drivers, but its hard to understand untill you do it your self.. pretty cool! but anyway enough gloating I think chuck has the answer time I supose will tell but this is the longest it ahs gone (ok) since the problem occerd. tnx everone for your help Eric smith ps about the time slips on ds. in the thred just just run it in realtime (text mode for better fps's) and hit the space bar to start recording and the space bar again to stop recording, it will stop the time slip after the quater mile bye itself. so no need to worry when to stop it just make sure its after the quater mile.
Im sorry I just noticed you have ds 2.1 mine is 1.5 I dont know if the info I gave you will work sorry Steve.Try it anyway
eric smith
Eric,
I gotta try that. I just need to get my laptop running on battery power again. Here's a great idea posted to the list by Mark Herrly:
When I installed my DS I cut a small (1/8") sliver of a plastic window tint
squeege and pushed it into the connector before installing it to keep it from
going onto the board too far. I also made darned sure to clean the board VERY
WELL. So far, so good..
--------------------------------------
Mark Herrly '87 GN U1ARUNIT on Turbobuick BB
U1arunit@aol.com GSCA 5726 Turbo Regal Web Ring Now updated:
http://members.aol.com/u1arunit/MarksGN.htm
I can agree with what Chris has posted on this, my ecm is acting strange ,but this happened just recently, we do use our DS a lot and may have some how shoved the cable in too far. I will test this tomorrow. but our car is only acting strange when the DS is plugged in.
Who has 2.1 for DS I thought 1.51 was the latest version??????
Well lets end this thred on a good note. I extensivly diagnosed the problem and found Chuck looks to be correct. My problem deffinatly was the ds cable and I do beleive it was on to far. I have found I can reduse my problem bye moving the plug out farther( and I'm sure I can cure it compleetly with some cleaning and adjusting of the conection) but so far the way to CURE it, is to dissconnect. I am confident it is a connection problem more then a rf. but I'll bet they both play a good part tnx all I hope I can help somone in the future as well as you have helped me on this cya Eric Smith