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740 B234 Engine wiring / No spark

8

8587turbo

Member
Joined
Dec 31, 2003
Location
Montana
Switched out a 89 B234 engine & installed a 1990 B234 engine using the 1990 engine wiring harness . Now no spark , has anyone encountered this problem? What I would really like to have is the wiring changes made to the 1990 B234 wiring harness as its condition is better than the 89. Or wiring for 89 & 90 engine wiring harness B234 with 2.4 engine management system . Thanks
 
All I can suggest is try the old wiring harness if it was working.

Disconnecting it from the engine can be a pain but so can a no start situation. I am not sure of any electrical changes from 1989-1990
 
Yeah, looking for a easy way out & that's my plan if no one has run into same problem. Will do some meter checks for voltage, grounds starting with power stage. BTW, have you seen a white 68 Firebird 350HO LHD running round NSW or ACT? I took one to Canberra in 69 & sold it to a bloke who was going to keep it forever!
 
Checking the CPS with Fluke meter the crank sensor reads .109vac on the car that fails to start & on a known good car that starts crank sensor reads .260vac.

I've switched out crank sensors with known good units, the sensor mount looks good, BUT could the sensor be too far away from flywheel ? Do you have a voltage value that comes off the crank sensor signal pins ? Battery is fully charged.Thanks
 
ZVOLV said:
The sensor makes it's own voltage.

CAN YOU READ OBD CODES?
Click to expand...

Yeah, I know that it makes its own voltage ,was trying to figure out what was a good voltage & after reading your no start thread I found out what it was, The problem was the air gap between the sensor & flexplate/flywheel , the sensor mount got bumped out of place when installing engine (sticks out like a sore thumb ). FYI, the air gap was at .035 & it did make voltage just not enough to trigger. Air gap is about .020 now, & of course I had to remove trans to check & repair. Thanks for posting your no start thread.
 
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