1987 Toyota 4Runner engine runs bad

Tiny
EDDIE440
  • MEMBER
  • 1987 TOYOTA 4RUNNER
Engine Performance problem
1987 Toyota 4Runner 4 cyl Four Wheel Drive Manual 0

its had a new engine put in. The guy I got it from was running it with a carb. I took it off and put it back fuel injected like it came from the factory. Now it dont want to start and when it does it runs like junk. It will not idle and the only way you can start it is to prop onpen the mass air flow so the fuel pump runs. When running it run rough and skips. I have replace almost everything on it electrical and check everything else to make sure it tested right. Really frustrated and almost ready to put the carb back on.
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Tuesday, September 23rd, 2008 AT 2:06 PM

13 Replies

Tiny
RASMATAZ
  • MEMBER
Test the MAF what it does is ground the circuit opening relay in order for the fuel pump to fire up.

Clean out the idle air control valve and check the throttle position sensor closed and WOT voltages and also the O2 sensor
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Tuesday, September 23rd, 2008 AT 2:25 PM
Tiny
EDDIE440
  • MEMBER
Change the mass airflow sensor, completely cleaned the throttle body replaced tps, replaced fuel pump.
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Tuesday, September 23rd, 2008 AT 2:33 PM
Tiny
RASMATAZ
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The fuel pump is it the original when the carb is being use-There's a different in pressure between the 2.

Check fuel pressure and have you tried adjusting the air screw
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Tuesday, September 23rd, 2008 AT 2:38 PM
Tiny
EDDIE440
  • MEMBER
Changed pumps, air screw doesnt help
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Tuesday, September 23rd, 2008 AT 2:56 PM
Tiny
RASMATAZ
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Ignition components are they in good condition? Did you clean out the IACV? Ignition timing is it okay? Check the fuel pressure and exhaust system for restriction.

BTW I need the fuel pressure readings in order to get to other areas w/o this info I'm stuck
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Tuesday, September 23rd, 2008 AT 3:18 PM
Tiny
EDDIE440
  • MEMBER
Tried those, good fuel pressure
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Tuesday, September 23rd, 2008 AT 3:23 PM
Tiny
EDDIE440
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Unhooked the exhaust at the converter, thought that might be it, no change
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Tuesday, September 23rd, 2008 AT 3:25 PM
Tiny
RASMATAZ
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I need the actual pressure reading with and w/o the pressure regulator
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Tuesday, September 23rd, 2008 AT 3:26 PM
Tiny
EDDIE440
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Fuel pressure is at 36# book says must be between 33 to 38
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Tuesday, September 23rd, 2008 AT 3:27 PM
Tiny
EDDIE440
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Draining the fuel tank and replacing with fresh now. Maybe thats it. Just guessing have tried all other things that I can think of. By all the readings I get it should run perfect but it will not
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+1
Tuesday, September 23rd, 2008 AT 3:31 PM
Tiny
RASMATAZ
  • MEMBER
Have you checked for vacuum leaks and the vac hoses are routed propery to where its suppose to be.

Pull the vac hose from the regulator and check if it has gas in it or the reg
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Tuesday, September 23rd, 2008 AT 3:34 PM
Tiny
RASMATAZ
  • MEMBER
Since you have a repair manual check the injectors solenoid resistances
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Tuesday, September 23rd, 2008 AT 3:39 PM
Tiny
EDDIE440
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Thanks for the help but I think I will take the engine apart and check it. I have come to the conclusion that its internal, new engine or not its has to be internal because everything on the outside is right, everything test rite. There's nothing left but internal problems. Ie ring end gap, wrong pistons ect.
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Wednesday, September 24th, 2008 AT 8:43 AM

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