4jj1 surging while driving

ozzie1010
Posts: 14
Joined: Mon Dec 06, 2021 6:53 pm

Re: 4jj1 surging while driving

Post by ozzie1010 »

mydmax
i couldnt see yours so i have pmd you
Slant225
Posts: 1
Joined: Thu Nov 23, 2023 9:46 am

Re: 4jj1 surging while driving

Post by Slant225 »

@ozzie1010
Did you ever resolve the problem?
My 4JJ1 Colorado does exactly the same thing, 1500-2000 rpm surging, but not on cruise control or under acceleration.
MAP, MAF swapped out for testing
SCV replaced
EGR valve blanked
Accelerator position sensor replaced.
No difference found.
I'm thinking it might be throttle body TPS or the control motor.
Any luck?
ATFS__RZ4E
Posts: 7
Joined: Sat Aug 12, 2023 10:52 am

Re: 4jj1 surging while driving

Post by ATFS__RZ4E »

Hey Slant225, could you solve the issue? I have a similar issue on a 1.9l EURO Diesel engine...
mydmax
Posts: 2066
Joined: Sat Oct 12, 2013 8:36 pm

Re: 4jj1 surging while driving

Post by mydmax »

Does it happen with the Aircon ON or OFF. If while aircon is ON , it might be a poor earth lug contact in engine bay and becoming higher than -ve when the aircon turns the compressor ON and reducing the signal of a fuel related sensor. Aircon will be felt slightly when the compressor turns on each time it need to make COOL. ie, higher need for cooling the surge will be more often as the comp pulls in. The compressor load AND the voltage level mentioned will be happening at the same time and increasing the feel of loss and then surge as the compressor turns OFF each time it cycles.

Don't change parts until ALL the basics are checked and certified as OK. Wires tested for continuity, connections at loom plugs, earthing points to negative etc.
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