1987 Pthfinder

Tiny
CCAMBEL
  • MEMBER
  • 1987 NISSAN PATHFINDER
  • 260,000 MILES
1987 Nissan VG30i in Pathfinder.
newly rebuilt from previous running engine.
Replaced block and fresh heads used original working components.
I did all the work described below.

Freshly installed vacuum hoses. 
New fuel pump.  
throttle body recently disassembled and cleaned.
Cleaned two idle solenoids,  
injectors. Throttle position sensor and wiring
Compression good.  
Charcoal can and vacuum motors good.
Electrical connections all good.
Compression good. 
Triple checked the timing belt!

Post rebuild start up yielded  these symptoms:

Engine rpm fluctuates ~600 to 1200 rpm in a ~3 second cycle,  
as if pressing gas ped then releasing; steady up then drop.
Grey smoke. Plugs get sooty.
Key on engine off: fuel pressure goes to about 36 (correct). 
Engine running: pressure fluctuates with rpm
Pressing gas (as if to rev) engine bogs and stalls.
Unable to set the distributor timing.

Can almost control fluctuation with hand over TBI intake.

No ECU error code (44).

Could this be a bad fuel pressure regulator? 
Some internal leak in the throttle body?

Been trying to figure this out for months!
Please Help and many thanks.
Curtis in Austin
 
Wednesday, May 15th, 2013 AT 5:07 PM

6 Replies

Tiny
ASEMASTER6371
  • MECHANIC
  • 52,797 POSTS
It think you have an issue with the timing at the distributor.

Cannot set timing with distributor?

Roy
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Wednesday, May 15th, 2013 AT 6:04 PM
Tiny
CCAMBEL
  • MEMBER
  • 2 POSTS
Thanks for your reply.
Setting distributor difficult while rpm jumping all over.
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Wednesday, May 15th, 2013 AT 9:45 PM
Tiny
EMMANUEL CORTEZ
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Was the distributor timing the issue? I'm having the same problems.
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Wednesday, May 1st, 2019 AT 10:20 AM
Tiny
ASEMASTER6371
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This is a work in progress question.

Roy
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Wednesday, May 1st, 2019 AT 12:58 PM
Tiny
EMMANUEL CORTEZ
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I have managed to fix this issue with my pathfinder, I had to replaced injectors along with ecu at the same time, changing ecu or injectors one prior to another will cause problems to one another, both had to be replaced at same time, my pathfinder also gave me these issues because the head temp sensor going bad and harness being corroded.
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Wednesday, December 18th, 2019 AT 11:40 AM
Tiny
ASEMASTER6371
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Thanks for the update.

Roy
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Wednesday, December 18th, 2019 AT 11:53 AM

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