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1990 Toyota Pickup Starting & Running Problems

Tiny
EIGHTRAC2
  • MEMBER
  • 1990 TOYOTA PICKUP
1990 Toyota Pickup 240000 miles

my 90 toyota pickup will sometimes start & run just fine. Other times it won`t start right away if I click the starter about 20 times it will start. This has nothing to do with the starter or battery it cranks over good.I jumped the diagnostic fuel pump terminals like you said & the truck runs just fine. How long can I run this truck in that mode till I can repair it & do have any ideas whats causing this problem maybe a relay or wiring.

90 toyota pickup / 22re / fi / 2wd / 4 speed stick

thank you
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Sunday, October 24th, 2010 AT 1:27 PM

7 Replies

Tiny
RASMATAZ
  • MECHANIC
  • 75,992 POSTS
Hi eightrac2, Welcome to 2carpros and TY for the donation

Remove the jumper from the DLC and block wide open the airflow meter vane flap and see what happens-let me know.

As long as you want -mine was a defective airflow meter and the jumper is still in place its almost 3 yrs now-

Could also be the circuit opening relay-the airflow meter has to ground the Fc terminal of the COR to power the fuel pump
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Sunday, October 24th, 2010 AT 1:54 PM
Tiny
EIGHTRAC2
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Will my truck pass a california smog test with jumper wire left in.I`am not sure what your talking about blocking wide open airflow meter vane flap & then trying to start.
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Sunday, October 24th, 2010 AT 9:07 PM
Tiny
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  • MECHANIC
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If there's no CEL On, you should be able to make it thru.

Description and Operation

Air Flow Meter


https://www.2carpros.com/forum/automotive_pictures/12900_maf_5.jpg



A Bosch vane type airflow meter is mounted in the air induction system near the air cleaner. The airflow meter measures intake air volume, and converts these readings into voltage signals by means of a variable resistor (potentiometer). These voltage signals are then sent to the ECU and used to determine injection duration and proper fuel delivery. When intake air volume is low, the voltage is high; when the intake air volume is high, the voltage signal is approximately zero.
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+1
Sunday, October 24th, 2010 AT 9:29 PM
Tiny
EIGHTRAC2
  • MEMBER
  • 4 POSTS
Can I bypass the maf : mass air flow meter till I can find a replacement part.

Thank you
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Monday, October 25th, 2010 AT 9:53 PM
Tiny
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You don't have to worry about bypassing the airflow meter all it does for the fuel pump is to ground the circuit opening relay to power the fuel pump-you can keep your jumper in the diagnostic link connnetor hooked-up
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Monday, October 25th, 2010 AT 10:05 PM
Tiny
EIGHTRAC2
  • MEMBER
  • 4 POSTS
The maf is damaged I tryed to inspect it & now my truck runs bad & won`t idle.
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Monday, October 25th, 2010 AT 10:32 PM
Tiny
RASMATAZ
  • MECHANIC
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The computer has to see an input signal ( airflow volume ) to control the fuel as needed also with other sensors-Dunno how to bypass it w/o the signal-Sorry
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Tuesday, October 26th, 2010 AT 12:09 AM

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