7165 ECM, Batch Fire and 7/4 Lobe Swap
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7165 ECM, Batch Fire and 7/4 Lobe Swap
Will a 1227165 ECM in an '89 L98 correctly time injector
pulses for use with a cam that has the 7 and 4 lobes swapped?
My vote is that it will.pulses for use with a cam that has the 7 and 4 lobes swapped?
Cylinder location:
2 - 4 - 6 - 8 Chevy
1 - 3 - 5 - 7
Firing order:
1-8-4-3-6-5-7-2 Chevy (OEM)
1-8-7-3-6-5-4-2 Chevy (7/4 Swap)
Summarized from 'Corvette Fuel Injection' Probst, Charles O.
Bentley Publishers, ISBN 0-8376-0861-9
The L98 uses an electronically controlled HEI distributor.
Instead of weights, springs and vacuum; Electronic Spark
Timing (EST) controls spark advance. The rotor, cap and
wiring routing determine which plug is fired by the secondary
windings of the coil-in-cap.
As for the injectors on the L98
"For every two revolutions of the crankshaft, each gang of
four injectors opens and closes twice, alternating left
bank (four cylinders), right bank (four cylinders). GM
-speak: "Double-Fire
Comments, opinions, links to previous threads?four injectors opens and closes twice, alternating left
bank (four cylinders), right bank (four cylinders). GM
-speak: "Double-Fire
.
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From: Chasing Electrons
Car: check
Engine: check
Transmission: check
Re: 7165 ECM, Batch Fire and 7/4 Lobe Swap
You are correct as to the 7/4 swap not being affected by the injection timing, or vice versa.
However, Probst, Charles O., is incorrect. The '165 & '7730 ECMs only have 1 injector driver in them. All 8 injectors fire at the same time. Double fire is when they fire once per revolution (double pulse per intake stroke per cylinder), and single fire is when they fire once every 2 revolutions (single pulse per intake stroke per cylinder).
RBob.
However, Probst, Charles O., is incorrect. The '165 & '7730 ECMs only have 1 injector driver in them. All 8 injectors fire at the same time. Double fire is when they fire once per revolution (double pulse per intake stroke per cylinder), and single fire is when they fire once every 2 revolutions (single pulse per intake stroke per cylinder).
RBob.
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From: Middleburg Hts. OH
Car: 85 T/A, 92 Rs
Engine: L98:D,L03:<
Transmission: 700r4x2
Axle/Gears: 3.23 bw, 2.73 10 bolt.
Re: 7165 ECM, Batch Fire and 7/4 Lobe Swap
wow so we're leaving even more on the table vs sequential then i thought. im surprised we don't have more fuel puddling issues, 8 injector batch fire must leave some fuel waiting for awhille.
Joined: Jan 2005
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From: Hurst, Texas
Car: 1983 G20 Chevy
Engine: 305 TPI
Transmission: 4L60
Axle/Gears: 14 bolt with 3.07 gears
Re: 7165 ECM, Batch Fire and 7/4 Lobe Swap
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From: Middleburg Hts. OH
Car: 85 T/A, 92 Rs
Engine: L98:D,L03:<
Transmission: 700r4x2
Axle/Gears: 3.23 bw, 2.73 10 bolt.
Re: 7165 ECM, Batch Fire and 7/4 Lobe Swap
i need a translation fast355 dunno what you're getting at. but this thread got me thinking about the pcm you're using in your van, could we not easily apply it to a MAF 5.7 l98 with a map sensor attached? sounds easier then to do it on tbi!
dunno what kind of epuipment it has injector driver wise but i remember reading that it had batch and sequential fire (for 8 injectors?) and that it is still obd1, what do you think?
dunno what kind of epuipment it has injector driver wise but i remember reading that it had batch and sequential fire (for 8 injectors?) and that it is still obd1, what do you think?
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