94 4Runner 3.0 fuel pressure drops to zero - Toyota Nation Forum : Toyota Car and Truck Forums
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post #1 of 4 Old 01-05-2019, 12:23 PM Thread Starter
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94 4Runner 3.0 fuel pressure drops to zero

Anyone idea: no fuel leaks, engine runs OK, fuel pump new, fuel pressure regulator new, injectors new. Engine shut down fuel pressure immediately drops to zero. Vehicle specific manual say's fuel pressure should remain above 21 psi for 5 minutes. Hard to start at times. Could be related?
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post #2 of 4 Old 01-05-2019, 01:16 PM
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Originally Posted by turner_resort View Post
Anyone idea: no fuel leaks, engine runs OK, fuel pump new, fuel pressure regulator new, injectors new. Engine shut down fuel pressure immediately drops to zero. Vehicle specific manual say's fuel pressure should remain above 21 psi for 5 minutes. Hard to start at times. Could be related?
It shouldn't drop to zero.By maintaining pressure the system is always primed so your starting issue is most likely related. Is the CEL on? Did you do a check for codes? Possible bad gas cap and/or a bad check valve in the nw fuel pump. If the check valve is faulty the fuel just returns to the tank.
After replacing all the parts you mentioned did it ever run correctly> OEM or after-market parts?
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post #3 of 4 Old 01-07-2019, 01:54 AM
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There are a few tests that you can isolate where yer fuel pressure loss is occuring at. Where did you hook up yer fuel pressure gauge at? Are you sure it's a good connection with no leaks?

Did you replace the parts with OEM or aftermarket parts? If aftermarket, which brand(s) did you use?

Are the injectors new or refurbished? There are instances where refurbished injectors were still leaking while under pressure. Did you replace the cold start injector as well?

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post #4 of 4 Old 01-07-2019, 02:09 AM
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I know this thread is about the 3.0 engine but this referenced thread is about the injector issue.
https://www.tacomaworld.com/threads/...4l-5vz.354399/

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