The difference between a 5.0 ecm and a 5.7 ecm
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Junior Member
Joined: Apr 2010
Posts: 26
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From: Statesville, NC
Car: 89 Trans AM
Engine: L98 5.7
Transmission: 5speed
The difference between a 5.0 ecm and a 5.7 ecm
i bought an 89ta that was originally a 5.0 but the po swapped in the l98. my concern is i dont know if he put the different computer in the car, because there are some running issues (check my other posts). so i just need to know how to identify the right ecm, prom, memcal, calpack stuff i keep hearing about while reading these threads. any help would be great thank you.
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From: Glen Park, NY
Car: 1987 IROC-Z
Engine: TPIS II Supercharged w/Nitrous
Transmission: 700R4 Probuilt
Axle/Gears: 3:73 Richmond 12 Bolt
Re: The difference between a 5.0 ecm and a 5.7 ecm
The ECM's are exactly the same. The difference isn't in the ecm it is the programming of the prom. Things to consider as long as they are both TPI.. Fuel injectors
5.0 ran 19 lb injectors
5.7 ran 24 lb injectors
Were both Mass Air Flow Sensor's? MAF and MAP used different programming
The Knock sensor on 5.7 was different than the 5.0
Everything else I believe is the same.
I have both ECM's downstairs and I think both MEMCALS.. the 5.7 used the AUJP MEMCAL if the car has vats and map sensor.
5.0 ran 19 lb injectors
5.7 ran 24 lb injectors
Were both Mass Air Flow Sensor's? MAF and MAP used different programming
The Knock sensor on 5.7 was different than the 5.0
Everything else I believe is the same.
I have both ECM's downstairs and I think both MEMCALS.. the 5.7 used the AUJP MEMCAL if the car has vats and map sensor.
Joined: May 2007
Posts: 2,340
Likes: 2
From: Montreal, Canada
Car: 1986 Chevrolet Camaro IROC-Z28
Engine: TPI 310ci (LB9)
Transmission: Custom Rebuilt 700R4 - 2600 Stall
Axle/Gears: 10 bolt, 3.73 Eaton Limited-Slip
Re: The difference between a 5.0 ecm and a 5.7 ecm
I thought 5.7's came with 22lbs injectors?
Thread Starter
Junior Member
Joined: Apr 2010
Posts: 26
Likes: 0
From: Statesville, NC
Car: 89 Trans AM
Engine: L98 5.7
Transmission: 5speed
Re: The difference between a 5.0 ecm and a 5.7 ecm
say they didnt replace the computer or the prom, how would i go about acquiring one for the L98?
Joined: Jun 2000
Posts: 5,364
Likes: 51
From: Enschede, Netherlands
Car: 82 TA 87 IZ L98 88 IZ LB9 88 IZ L98
Engine: 5.7TBI 5,7TPI 5.0TPI, 5,7TPI
Transmission: T5, 700R4, T5, 700R4
Axle/Gears: 3.08, 3.27, 3.45, 3.27
Re: The difference between a 5.0 ecm and a 5.7 ecm
The ECM's are exactly the same. The difference isn't in the ecm it is the programming of the prom. Things to consider as long as they are both TPI.. Fuel injectors
5.0 ran 19 lb injectors
5.7 ran 24 lb injectors
Were both Mass Air Flow Sensor's? MAF and MAP used different programming
The Knock sensor on 5.7 was different than the 5.0
Everything else I believe is the same.
I have both ECM's downstairs and I think both MEMCALS.. the 5.7 used the AUJP MEMCAL if the car has vats and map sensor.
5.0 ran 19 lb injectors
5.7 ran 24 lb injectors
Were both Mass Air Flow Sensor's? MAF and MAP used different programming
The Knock sensor on 5.7 was different than the 5.0
Everything else I believe is the same.
I have both ECM's downstairs and I think both MEMCALS.. the 5.7 used the AUJP MEMCAL if the car has vats and map sensor.
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Joined: Oct 2005
Posts: 1,050
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From: Glen Park, NY
Car: 1987 IROC-Z
Engine: TPIS II Supercharged w/Nitrous
Transmission: 700R4 Probuilt
Axle/Gears: 3:73 Richmond 12 Bolt
Supreme Member
iTrader: (1)
Joined: Oct 2005
Posts: 1,050
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From: Glen Park, NY
Car: 1987 IROC-Z
Engine: TPIS II Supercharged w/Nitrous
Transmission: 700R4 Probuilt
Axle/Gears: 3:73 Richmond 12 Bolt
Re: The difference between a 5.0 ecm and a 5.7 ecm
Was the car originally TPI or TBI
Was it MAF or MAP
Automatic or Manual
Example
1227165 -- was for TPI with MAF
1227730 -- was for TPI with MAP
proms are all different also.
AUJP memcal has VATS and MAP setup
I can't remember what MAF was..
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Joined: Sep 2009
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From: Downers Grove, IL
Car: 91 Z28 / 04 GTO
Engine: GMPP 350 TPI / LS1
Transmission: WC T5 / T56
Axle/Gears: 3.23 / 3.46
Re: The difference between a 5.0 ecm and a 5.7 ecm
Last edited by theNMBR27; Mar 7, 2011 at 09:59 PM.
Thread Starter
Junior Member
Joined: Apr 2010
Posts: 26
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From: Statesville, NC
Car: 89 Trans AM
Engine: L98 5.7
Transmission: 5speed
Re: The difference between a 5.0 ecm and a 5.7 ecm
Originaly it was a 5.0 tpi 5spd. Now it is a 5.7 tpi 5spd, they both had maf. I tried to get to the ecm yesterday but it didnt work out. I pulled the two panels off underneath the passenger dash and i still couldnt get to it enough to read the numbers. Is there an easier way to get to it?
Joined: May 2007
Posts: 2,340
Likes: 2
From: Montreal, Canada
Car: 1986 Chevrolet Camaro IROC-Z28
Engine: TPI 310ci (LB9)
Transmission: Custom Rebuilt 700R4 - 2600 Stall
Axle/Gears: 10 bolt, 3.73 Eaton Limited-Slip
Re: The difference between a 5.0 ecm and a 5.7 ecm
Pull the ECM out of the car.. It is being held there by 2 screws I think, maybe 3.
Thread Starter
Junior Member
Joined: Apr 2010
Posts: 26
Likes: 0
From: Statesville, NC
Car: 89 Trans AM
Engine: L98 5.7
Transmission: 5speed
Re: The difference between a 5.0 ecm and a 5.7 ecm
to get to these bolts, do i go through the bottom or remove the top of the dash or what?
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From: Flowood,MS
Car: 87 IROC Z
Engine: 5.7 L98 TPI
Transmission: 700r4,2500 stall
Axle/Gears: G80,10 bolt 3.42's
Re: The difference between a 5.0 ecm and a 5.7 ecm
from the bottom.Put your head down by the floor board close to the kick panel and look up.IIRC its 2 10mm bolt/screws.
Joined: May 2007
Posts: 2,340
Likes: 2
From: Montreal, Canada
Car: 1986 Chevrolet Camaro IROC-Z28
Engine: TPI 310ci (LB9)
Transmission: Custom Rebuilt 700R4 - 2600 Stall
Axle/Gears: 10 bolt, 3.73 Eaton Limited-Slip
Re: The difference between a 5.0 ecm and a 5.7 ecm
under that panel, the ECM has another two bolts that hold it down.. you'll need a flashlight and you have to stick ur head in there to see where they are but it's pretty easy to get them out).
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Joined: Jan 2006
Posts: 1,489
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From: Flowood,MS
Car: 87 IROC Z
Engine: 5.7 L98 TPI
Transmission: 700r4,2500 stall
Axle/Gears: G80,10 bolt 3.42's
Re: The difference between a 5.0 ecm and a 5.7 ecm
Oh yeah,I forgot some cars had the under dash panels.For some reason not all cars got them.
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