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Memcal or chip Help Please!

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Old Jun 16, 2008 | 06:48 PM
  #1  
vette9190's Avatar
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From: Lowell, In
Car: 1991 Chevy Camaro RS
Engine: 350 TPI
Transmission: 700R4,
Axle/Gears: 3.73 w/SLP Zexel Torsen Limited Sli
Memcal or chip Help Please!

OK so I just got my TPI swap running. So I decided to start burning my chips.
I started with my stock ANHY chip that came with my TPI. All I did was go in and disable vats. That worked great, the car ran good but no more vats. But then I decide to start making changes so I removed the chip and put in A S_AUJP chip that I burned suddenly the car won't stay running, it starts but dies right away, and my check engine light came on and stays on. So I decied to put the chip that had been working back in but I'm still having the same issue. It is like its not reading that the chip is there at all. Does anyone have any ideas if its my chips or a bad memcal. Anyway to troubleshoot this I really don't want to nor do I have the money to buy a new memcal. Do memcals go bad often? is there common Problems that can be fixed? or am I basically screwed here. I had been just swapping out the chip on the mecal but have recently ordered Moates G1 adapter but it has not yet arrived. Does anyone have any ideas for me or were to start.
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Old Jun 16, 2008 | 10:27 PM
  #2  
JP86SS's Avatar
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From: Browns Town
Car: 86 Monte SS (730,$8D,G3,AP,4K,S_V4)
Engine: 406 Hyd Roller 236/242
Transmission: 700R4 HomeBrew, 2.4K stall
Axle/Gears: 3:73 Posi, 7.5 Soon to break
Re: Memcal or chip Help Please!

When you made the change to AUJP did you adjust the displacement and injector size for your setup?
Could have been the problem if not.
When changing chips be sure to wait at least 5 seconds after key off for the ECM to power down. Pulling the chips when powered can cause trouble.
Be sure all of the connections are good on the chips you are swapping. There may be a bent pin or bad contact from handling.
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Old Jun 17, 2008 | 09:05 AM
  #3  
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From: Lowell, In
Car: 1991 Chevy Camaro RS
Engine: 350 TPI
Transmission: 700R4,
Axle/Gears: 3.73 w/SLP Zexel Torsen Limited Sli
Re: Memcal or chip Help Please!

Yes I did make adjustments for inhector and dispalcement. I also diasabled vats and reenabled all the emmisions for the smog pump and charcoal canister *** i still need to take emissions tests here.
I always disconnect the battery before changing my chip.
I have double and triple checked the pins to make sure they are straight and making proper contact. I have experience with IC chips in my job so I'm pretty famaliar with handleing them. I even have the proper tool for removal and replacement bc I deal with them so much at work.

I am thinking maybe the chip socket on the memcal is the problem???
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Old Jun 17, 2008 | 09:19 AM
  #4  
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From: NJ/PA
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Engine: Many
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Re: Memcal or chip Help Please!

so you've socketed the memcal? I'd check your solder connections.

once you get an adapter, if it was the socket, this should go away.
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Old Jun 17, 2008 | 12:44 PM
  #5  
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From: Lowell, In
Car: 1991 Chevy Camaro RS
Engine: 350 TPI
Transmission: 700R4,
Axle/Gears: 3.73 w/SLP Zexel Torsen Limited Sli
Re: Memcal or chip Help Please!

Yeah when I started this project originally it was five years ago(sidetracked by two kids and a divorce) and the adapter wasn't easily available. I have one on order from Moates but don't know when it will arrive I hope this fixes my prob bc I have no clue what else it may be. b
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Old Jun 19, 2008 | 07:37 PM
  #6  
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From: Lowell, In
Car: 1991 Chevy Camaro RS
Engine: 350 TPI
Transmission: 700R4,
Axle/Gears: 3.73 w/SLP Zexel Torsen Limited Sli
Re: Memcal or chip Help Please!

Got my adapter and tried it no luck.
At this point I'mclueless as to WTF is going on.
Somebody please help me.
Recap
I took out a chip i had burned that was working to try another chip it didn't work so i put the old chip back in after that it wouldn't run. I tried the original chip an a third burned chip i had but nothing. I changed the computer -nothing. Now I have the G1 adapter and still it won't run.

With the memcal in with no chip it will start but dies right away.
with the chip in it cranks but won't start plus i get a ticking noise from the dizzy.
same thing if I use the chip with the g1 adapter. Do I need a memcal or what? I am so Pissed right now bc it was running perfectly before i tried the chip swap what the **** could have happened. to cause this?
If I ordered a jet chip or something for the car does it come with a memcal? Could I use the g1 with it and change my chip or is there something special about the aftermarket setups that i wouldn't be able to do this? is there something else out there that i could to eliminate the need for the memcal or do I have to have one?
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Old Jun 20, 2008 | 04:07 PM
  #7  
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From: Lowell, In
Car: 1991 Chevy Camaro RS
Engine: 350 TPI
Transmission: 700R4,
Axle/Gears: 3.73 w/SLP Zexel Torsen Limited Sli
Re: Memcal or chip Help Please!

ok Well can anyone tell me what the difference between a MAP memcal and a MAF memcal? I have another TPI setup but its a MAF system with a 165 ECM
Could I use that memcal if i was to change the chip over?
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Old Jun 20, 2008 | 04:20 PM
  #8  
TF34MECHH's Avatar
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From: Battle Creek MI
Car: 90 RS
Engine: 350
Transmission: 700R4
Axle/Gears: 2.77
Re: Memcal or chip Help Please!

Maybe it is something other than the ecm/memcal. Try going through the A-3 no start chart and do all the checks. Anyone know what the symptoms are for a blown ECM fuse near the battery?
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Old Jun 20, 2008 | 08:40 PM
  #9  
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From: Lowell, In
Car: 1991 Chevy Camaro RS
Engine: 350 TPI
Transmission: 700R4,
Axle/Gears: 3.73 w/SLP Zexel Torsen Limited Sli
Re: Memcal or chip Help Please!

I'm pretty sure its the ECM Memcal that is what I was working on when it stopped working.
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Old Jun 21, 2008 | 08:37 AM
  #10  
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From: SE AZ
Car: 1990 Corvette, 1985 C-10 1979 Subun
Engine: 350, 406 HSR
Transmission: manual, 200 4r
Re: Memcal or chip Help Please!

MAF and MAP memcals are different, MAF has knock sensor hardware external to ecm, on the MAP you will see an extra board soldered over the limp home chips, this is the knock sensor circuits. I never tried it but I suppose you could remove the extra circuit board on the MAP prom. But the limp home chips would most likely be different.
If the only thing you did was mess with the prom by changing chips I suspect you have a bad solder joint on the prom. With the prom installed does it go to limp home mode? Cooling fans start running with key on? Can you get any fault codes?
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Old Jun 21, 2008 | 09:40 AM
  #11  
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From: Lowell, In
Car: 1991 Chevy Camaro RS
Engine: 350 TPI
Transmission: 700R4,
Axle/Gears: 3.73 w/SLP Zexel Torsen Limited Sli
Re: Memcal or chip Help Please!

I have the moates G1 now with the dip socket so that eliminates a bad solder joint. My fans are not hooked to the ecm as the wirijng for them was hacked off the harness when i bought it. It will go into what i believe is limp home it will start but not stay running. The ses light does not go off and it does not flash any trouble codes.
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Old Jun 21, 2008 | 11:52 AM
  #12  
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From: Lowell, In
Car: 1991 Chevy Camaro RS
Engine: 350 TPI
Transmission: 700R4,
Axle/Gears: 3.73 w/SLP Zexel Torsen Limited Sli
Re: Memcal or chip Help Please!

FIXED IT I got it fixed whew!!!
It was the memcal body. The Brown Plastic casing that everything plugs into.
I went to the junkyard today and grabbed an extra ecm and a few memcals none were actually for the car. No f bodies in the yard at all. I took it all apart and put everything on another body and it works great now.

One question though.
When I was troubleshooting this I decided to try something. it came to me after reading Rebuildmans reply When i changed everything over to the other memcal body i left the knock board off and the car still ran great and it did not give me any codes. is this board really all that necessary?
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Old Jun 23, 2008 | 11:25 AM
  #13  
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Re: Memcal or chip Help Please!

it's not neccessary unless you wish to maintain knock control. I'd solder it into the memcal, as it's not big deal to do, and it's worth it to have the additional safety feature.

the reason you see no codes is becuase the circuit isn't ever 'checked' with your code mask, except for presence of the knock sensor, which is detected inside the ecm, not the memcal. you'd get a code unplugging the sensor.

in some masks, the code will throw a high spark advance on first start-up and look for a knock, and set a code or reduce overall timing if it doesn't see and knock counts.
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Old Oct 24, 2009 | 01:35 AM
  #14  
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Re: Memcal or chip Help Please!

MEMCALS DO GO BAD! I took my '94 chevy g20 van 305 to a chevy dealer after replacing every possible sensor and even the timing chain with 2" of slack in it and still got MAP code 33 and oxy sensor code 45 after 5 seconds of very rough hunting idle upon start up SES light would come on and it would go into limp mode and idle better but gobbled up fuel and blew heavy black smoke and foulded the new plugs quickly. The chevy dealer told me it needed a new ecm. I told him he was wrong, he replced it anyway and it still did the same thing. He told me there was nothing he could do because all of his sophisticated diagnosis equipment told him the ecm was bad and charged $80 diagnosis. The key thing was that he then lent me the chevy manual that described how the engine starts on the distibutor module and immediately at 400 rpm switches timing duty over to memcal.

I took the van back home, diconnected the wire that forces the engine to run on distributor module only and noticed the idle smoothed out somewhat. I then went to a junkyard and picked up a used 1994 ecm from a Yukon with a 350. Pulled the memcal and put it in my 305's ecm. After letting the ecm go throuh idle learn procerss it now runs perfectly and idles like a dream with no service engine soon light!

There must not be much difference between a 350 prom and a 305 prom.

I'm no genius but nowhere on the internet or through any mechanic could I find out that YES INDEED MEMCALS DO GO BAD! In fact I was told by at least 6 mechanics and parts counter guys that they had never heard of a bad Memcal. GO FIGURE!
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