Please check out this scan data...Update to Failed ECM post
Thread Starter
Intermediate
Joined: Apr 2002
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From: Silverdale WA
Please check out this scan data...Update to Failed ECM post
New info...read my latest post at the bottom.
Well...after replacing the ECM on my car my EASE software will now at least "talk" to the computer, but the idle is still extremely rough...which is obvious when you look at the below data...Sooooo...what now???
First of all the MAF is a new Wells unit but the scan data is the same with the stock AC Delco on the car...flowing ~2800gm/s...that is out to lunch!!!
The second major concern is the timing...again 20-40deg adv...out to lunch!!!
HELP!!! I guess I am off to buy a timing light at least.
[Modified by gbr, 7:13 PM 5/13/2002]
[Modified by gbr, 5:38 AM 5/20/2002]
Well...after replacing the ECM on my car my EASE software will now at least "talk" to the computer, but the idle is still extremely rough...which is obvious when you look at the below data...Sooooo...what now???
First of all the MAF is a new Wells unit but the scan data is the same with the stock AC Delco on the car...flowing ~2800gm/s...that is out to lunch!!!
The second major concern is the timing...again 20-40deg adv...out to lunch!!!
HELP!!! I guess I am off to buy a timing light at least.
[Modified by gbr, 7:13 PM 5/13/2002]
[Modified by gbr, 5:38 AM 5/20/2002]
Race Director
Joined: Mar 1999
Posts: 12,597
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From: Bartlett Illinois
Re: Please check out this scan data...Update to Failed ECM post (gbr)
It is taking forever to display the graph.. could you email me the scan? I have ease and will loook at it at home. jdebuhr@attbi.com I will look it over tonight at home..
As for the 20-40 deg advance.. that sounds normal assuming the ECM is controlling it and you have not unplugged the EST bypass..
Just saw the Graph you are running rich.. what other mods have you done.. did you replace the MAF relays when you swapped the MAF?
[Modified by -=Jeff=-, 1:27 PM 5/13/2002]
As for the 20-40 deg advance.. that sounds normal assuming the ECM is controlling it and you have not unplugged the EST bypass..
Just saw the Graph you are running rich.. what other mods have you done.. did you replace the MAF relays when you swapped the MAF?
[Modified by -=Jeff=-, 1:27 PM 5/13/2002]
Drifting
Joined: Mar 2001
Posts: 1,636
Likes: 3
From: Lafayette IN
Re: Please check out this scan data...Update to Failed ECM post (gbr)
Like Jeff said, you are running really rich (BLMs bottomed out at 108).
What are your IAC counts? MAF can't read above 255gm/s so I think something is whacked with your scan tool (readings displayed incorrectly). You might just need to do a Minimum air set to bring the IAC back into operating conditions and then your BLMs would come back around 128. IAC should be between 10-40 counts in park with AC off. Also, make sure your exhaust system is not leaking in front of the O2 sensor.
What are your IAC counts? MAF can't read above 255gm/s so I think something is whacked with your scan tool (readings displayed incorrectly). You might just need to do a Minimum air set to bring the IAC back into operating conditions and then your BLMs would come back around 128. IAC should be between 10-40 counts in park with AC off. Also, make sure your exhaust system is not leaking in front of the O2 sensor.
Burning Brakes
Joined: Jan 2002
Posts: 893
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From: Liberal Kansas
Re: Please check out this scan data...Update to Failed ECM post (gbr)
The adv of 20-40 is about right. Mine runs 18-36 with ECM control. You are running rich and I think HighHopes85 has a cood idea. . If your scan tool is showing IAC counts below 5 look for vacuum leaks or the adjustment of the IAC is incorrect. If you have a excessively high reading on your IAC the ECM could be trying to increase Idle spped due to perceived need for more output from the alternator. With the key on engine off your IAC position should be between 100-150. Now I am confused on your MAF readings. Hope this helped some
Thread Starter
Intermediate
Joined: Apr 2002
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From: Silverdale WA
Re: Please check out this scan data...Update to Failed ECM post (Rob90)
Thanks so far...IAC counts start at ~150 and level at ~70 but are erratic like the RPM and MAF...I just can't figure out which component is causing the erratic behaviour...I am going to try to change the MAF relays tonight if I can pick them up locally. I will also try to clean the IAC and reinstall.
Thread Starter
Intermediate
Joined: Apr 2002
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From: Silverdale WA
Re: Please check out this scan data...Update to Failed ECM post (gbr)
Well I had a chance to get to the MAF relays...no change after the install... :(
The car runs exactly the same (and the scanner output is the same) even when the MAF is disconnected...I guess I will check continuity from MAF to ECM.
The car runs exactly the same (and the scanner output is the same) even when the MAF is disconnected...I guess I will check continuity from MAF to ECM.
Drifting
Joined: Mar 2001
Posts: 1,636
Likes: 3
From: Lafayette IN
Re: Please check out this scan data...Update to Failed ECM post (gbr)
Just a thought. I don't know your full list of mods, so take this with a grain of salt.
The 24lb-hr injectors with 45 psi of fuel pressure should flow enough fuel for a 219 cam with a SuperRam manifold. With the stock runners and manifold, even with your exhaust, chip, and open lid *might* be just getting too much fuel. Let's put it this way--I was experiencing MUCH more overkill than this. I slapped 30lb-hr injectors into my 85 with a cam and 1.6rr's. My logs looked the EXACT same. I couldn't tune with the AFPR enough because I was just getting so much fuel in there in the first place.
What I would do:
Adjust minimum air rate so that your 70 count goes down to about 20.
Adjust timing to 6 degrees BTDC (really don't want more than 10 with a Hypertech chip).
Make sure that your ECT (engine coolant temp sensor that goes to the ECM (not the dash) reads about the same as the IAT (intake air temp) temp at startup after the engine has sat for a while).
Pay attention to injector pulse-width and let us know what that is.
Above all, good luck!
BTW-Most aftermarket 24lb-hr injectors will flow closer to a GM rate of 26-27 lb-hr.
The 24lb-hr injectors with 45 psi of fuel pressure should flow enough fuel for a 219 cam with a SuperRam manifold. With the stock runners and manifold, even with your exhaust, chip, and open lid *might* be just getting too much fuel. Let's put it this way--I was experiencing MUCH more overkill than this. I slapped 30lb-hr injectors into my 85 with a cam and 1.6rr's. My logs looked the EXACT same. I couldn't tune with the AFPR enough because I was just getting so much fuel in there in the first place.
What I would do:
Adjust minimum air rate so that your 70 count goes down to about 20.
Adjust timing to 6 degrees BTDC (really don't want more than 10 with a Hypertech chip).
Make sure that your ECT (engine coolant temp sensor that goes to the ECM (not the dash) reads about the same as the IAT (intake air temp) temp at startup after the engine has sat for a while).
Pay attention to injector pulse-width and let us know what that is.
Above all, good luck!
BTW-Most aftermarket 24lb-hr injectors will flow closer to a GM rate of 26-27 lb-hr.
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Thread Starter
Intermediate
Joined: Apr 2002
Posts: 46
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From: Silverdale WA
Re: Please check out this scan data...Update to Failed ECM post (HighHopes85)
Now I have checked continuity from the MAF to the ECM. I guess that my thinking is the the MAF reading of 2000+ are so out of whack that the computer can't determine the right fuel to dump in for the mixture. I did come up with some very interesting data during the continuity check. On the Wells MAF pins A and B are shorted. A is grounded so that means that B, which is a +5volt return (out of haynes) to the ECM is also grounded. The stock Bosch MAF has resistance between all pins...no shorts no opens. The Wells is open between D and E and shorted from A to B. Is the Wells SU145 MAF actually a replacement for the 89 Vette? (i got that impression from the forum).
My thinking is that I need to get the MAF counts down to <255 before I can determine the problem with this car. Possibly I had a bad MAF, then bought a Wells MAF which is incompatible...So maybe I should buy another MAF.
I am going to try all that Highhope85 has sugested as they all sound resonable and will help performance reguardless. I will post again when I get home and can get the pulse width data...I think it is in the mid 2ms range?
My thinking is that I need to get the MAF counts down to <255 before I can determine the problem with this car. Possibly I had a bad MAF, then bought a Wells MAF which is incompatible...So maybe I should buy another MAF.
I am going to try all that Highhope85 has sugested as they all sound resonable and will help performance reguardless. I will post again when I get home and can get the pulse width data...I think it is in the mid 2ms range?
Race Director
Joined: Mar 1999
Posts: 12,597
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From: Bartlett Illinois
Re: Please check out this scan data...Update to Failed ECM post (gbr)
GBR, I am unable to use my desktop to check out the data.. can you convert it to an XLS for me and email it to me? I need to get the upgrade from Ease for Win 2000
what version of Ease do you have. I just remembered there is a patch to correct the MAF data depending on the version you have
what version of Ease do you have. I just remembered there is a patch to correct the MAF data depending on the version you have
Thread Starter
Intermediate
Joined: Apr 2002
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From: Silverdale WA
Re: Please check out this scan data...Update to Failed ECM post (-=Jeff=-)
I am sending the zipped xls file from my hotmail account. I have EASE version 1.0.12.1 which I received only one week ago but I will check their site for an update...that would be great news if I could at least get accurate readings and stop chasing ghosts.
Thread Starter
Intermediate
Joined: Apr 2002
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From: Silverdale WA
Re: Please check out this scan data...Update to Failed ECM post (-=Jeff=-)
Thanks for the files Jeff. I am running a Hypertech street/thermo prom. I have a pocket programmer in hand and the Craig Moates ZIF enroute but am a newbie to programming. I will also scan at various speeds but don't have alot of time. I am going to try to clean and reset the IAC tonight. I will post again tomorrow morning.
Can you explain why you knew I was Rich? BLM was mentioned but I don't know technically what that is.
Can you explain why you knew I was Rich? BLM was mentioned but I don't know technically what that is.
Melting Slicks
Joined: Apr 2001
Posts: 2,120
Likes: 222
From: Ca.
Re: Please check out this scan data...Update to Failed ECM post (gbr)
Blm is long term fuel trim-you want it at 128. If it's less than 128 you're rich and the ecm is pulling fuel out in order to maintain a fuel/air ratio of 14.7:1-however you're at the max amount it can correct to, so it really is rich now.
Since you have the pp-try changing your fuel inj. constant first. Basically you lie to the ecm-tell it the inj. are bigger and then the ecm puts in less fuel.
Also with those maf readings-any codes??? You could try unplugging the maf-then it will go into "fail-soft" mode, sets the code and then uses predetermined maf readings-you should get reasonble maf gps readings then.
Have fun tuning!
Since you have the pp-try changing your fuel inj. constant first. Basically you lie to the ecm-tell it the inj. are bigger and then the ecm puts in less fuel.
Also with those maf readings-any codes??? You could try unplugging the maf-then it will go into "fail-soft" mode, sets the code and then uses predetermined maf readings-you should get reasonble maf gps readings then.
Have fun tuning!
Thread Starter
Intermediate
Joined: Apr 2002
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From: Silverdale WA
Re: Please check out this scan data...Update to Failed ECM post (drive it)
Yet another update. The MAF readout is now in spec...thanks to Jeff for the update to the EASE software. I pulled the TB off to get the IAC valve out. Had to use a vise and vise grips to get it out. Somebody went crazy with the locktite. Anyway...the port was full of carbon build up and the "needle" looked worn so I am ordering a new one which will be here Friday. There was also a crack in the gasket that was letting air in to the TB which would throw off the Mass Air Flow. I guess i'll bypass the TB and remove the frisbee while I wait for the IAC. I'll update everyone Friday.
[Modified by gbr, 6:56 AM 5/16/2002]
[Modified by gbr, 6:56 AM 5/16/2002]
Race Director
Joined: Mar 1999
Posts: 12,597
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From: Bartlett Illinois
Re: Please check out this scan data...Update to Failed ECM post (gbr)
Also put a stock PROM back in.. my guess is that the Hypertech PROM is causing you to run rich. As stated above.. BLM should be 128.. if lower then 128 it is rich and above 128 lean..
As for the MAF spec.. it the reading was off by 2 decimal places
[Modified by -=Jeff=-, 8:00 AM 5/16/2002]
As for the MAF spec.. it the reading was off by 2 decimal places
[Modified by -=Jeff=-, 8:00 AM 5/16/2002]
Thread Starter
Intermediate
Joined: Apr 2002
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From: Silverdale WA
Re: Please check out this scan data...Update to Failed ECM post (-=Jeff=-)
Well here is the update that I thought would be here Friday. I had followed all of the above advice except for setting base timing (I had to get a new timing light) all with the same results at the end...rough idle and extreme loss of power under load. So today I went to get the timing light. I have noticed that when connected to #1, #3, #5, and #7 plug wires that I am getting intermitent spark. Spark is good on the even side. I am so pissed that I have replaced $1200 dollars in parts and $350 on scanner software just to find bad spark is likely my problem.
So here's the question now. What is the most likely failed component?
Coil, Cap, Rotor, Distributer, Ignition Module...?? (I have already replaced the wires and plugs previously.)
So here's the question now. What is the most likely failed component?
Coil, Cap, Rotor, Distributer, Ignition Module...?? (I have already replaced the wires and plugs previously.)
Drifting
Joined: Mar 2001
Posts: 1,636
Likes: 3
From: Lafayette IN
Re: Please check out this scan data...Update to Failed ECM post (gbr)
Define intermittent. Reason I ask is because there will be a slight amount of spark scatter at idle.
But just on the drivers side makes sense that you have wires arcing. It is a tough call because those don't fire in any discernible fashion with the passenger side.
I would get a spray bottle and mist the plug wires with H20 at night (tap water, not deionized). Look for blue arcing outdoors with all the lights off.
Also, make sure you have the wires that cross sides (3 and 2) running in front of the distributor and away from the condensor wires (3 wires that run out of the front side of the distributor to the cap).
[Modified by HighHopes85, 3:04 AM 5/20/2002]
But just on the drivers side makes sense that you have wires arcing. It is a tough call because those don't fire in any discernible fashion with the passenger side.
I would get a spray bottle and mist the plug wires with H20 at night (tap water, not deionized). Look for blue arcing outdoors with all the lights off.
Also, make sure you have the wires that cross sides (3 and 2) running in front of the distributor and away from the condensor wires (3 wires that run out of the front side of the distributor to the cap).
[Modified by HighHopes85, 3:04 AM 5/20/2002]
Thread Starter
Intermediate
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From: Silverdale WA
Re: Please check out this scan data...Update to Failed ECM post (HighHopes85)
HighHopes85...by intermittent, I mean that the plug #1 will fire (according to the timing light) 3-5 times in a row, then not fire 1-2 times then fire 6-8 times then not fire 3-5 times...basically a very sporadic rate with long periods of not firing. Plug #3 is worse. When I connected the light to #3 it took a good 5 seconds before it fired at all then fired 2-3 times then no fire again. I suspected the light but it fires fine on the even side. If I remember right (I'm at work now) 2 goes around the front and 3 around the back but they have always run that way.
Drifting
Joined: Mar 2001
Posts: 1,636
Likes: 3
From: Lafayette IN
Re: Please check out this scan data...Update to Failed ECM post (gbr)
HighHopes85...by intermittent, I mean that the plug #1 will fire (according to the timing light) 3-5 times in a row, then not fire 1-2 times then fire 6-8 times then not fire 3-5 times...basically a very sporadic rate with long periods of not firing. Plug #3 is worse. When I connected the light to #3 it took a good 5 seconds before it fired at all then fired 2-3 times then no fire again. I suspected the light but it fires fine on the even side. If I remember right (I'm at work now) 2 goes around the front and 3 around the back but they have always run that way.
I was going to mention the pickup coil going out BUT it would do the same thing on the pass. side bank also.
