500EFI Help!
#21
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Im gonna pull the distributor caps off, inspect and check. Thanks Sydwayz and Mike T for the idea. One other thing worth noting is that the tachs are jumping around above 3000 rpm.
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#25
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Checked both distributer caps and rotors. Checked the grounds in the back of the engine. They all looked OK. Man! this has me stumped.
It seems like both motors are in choke mode. Anybody else think of something to check or try?
It seems like both motors are in choke mode. Anybody else think of something to check or try?
#26
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OK after much troubleshooting, I see that the engine is only producing 7-1/2 – 8 inches of vacuum which seems to be effecting the map sensor. The Map volts at idle is high with engine at operating temp of 140*. With the engine idling, I tried covering the IAC port in the throttle body to see if it would indicate a vacuum leak. Covering the hole about stalls the engine.
RPM / Map Voltage
Idle – 3.80 V
1000 – 3.72 V
1500 – 2.72 V
2000 – 2.11 V
2500 – 2.11 V
500EFI details
525 cam – by Crane – .610/.632 lift 236/242 degrees duration @.050 114* LS
Dart 308 Heads
9:1 CR
AZM throttle body
80 hrs on motors
Compression on each of the 8 cylinders ~120 lbs
With the new information, can anybody suggest what to do next?
RPM / Map Voltage
Idle – 3.80 V
1000 – 3.72 V
1500 – 2.72 V
2000 – 2.11 V
2500 – 2.11 V
500EFI details
525 cam – by Crane – .610/.632 lift 236/242 degrees duration @.050 114* LS
Dart 308 Heads
9:1 CR
AZM throttle body
80 hrs on motors
Compression on each of the 8 cylinders ~120 lbs
With the new information, can anybody suggest what to do next?
#27
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OK thanks to everyone who offered advice - the issue turned out to be the modules inside the distributor which were not holding timing. Replaced and solved the issue.
#28
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seems strange that the both went bad at the same time.
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snowrunner (06-26-2020)