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Mastertech 1
Mastertech 1, Toyota Technician
Category: Toyota
Satisfied Customers: 2261
Experience:  ASE Master Technician with over 30 years of experience, including Toyota and Toyota Hybrid.
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Car won't accelerate. Seems to backfire under throttle

Customer Question

Car won't accelerate. Seems to backfire under throttle
Submitted: 11 months ago.
Category: Toyota
Expert:  Mastertech 1 replied 11 months ago.

Hello: Are you getting any codes? (Is check engine light-on?) Will it idle good? Thanks, ***** *****

Customer: replied 11 months ago.
Had IACV p1652 control code consistently and p0171. Once cleared the p0171 has not come back on. The IACV is a few months old. Idle is ok but not great. Start up is slightly slower than normal. Idles at 800rpm when cold, 1000 when warm. I can rev in neutral or park but in gear it bogs down under any acceleration. Did multiple vacuum and boost leak tests up to 15 psi and holds well. Also the vacuum at idle is slightly off? Was -21 a few month's back now it's -19
Expert:  Mastertech 1 replied 11 months ago.

At this point you need to test the fuel pressure, Low fuel pressure will cause, this issue (you will hear a back fire type noise thru the air intake assembly)A week fuel pump or restricted fuel filter will cause low fuel pressure, causing this condition, also on these vehicles, a restricted cat. converter will also cause this (more so after it is warmed-up, Thanks, ***** ***** me know if I can be of any other assistance with this issue.

Customer: replied 11 months ago.
I thought so, ill try to check the injectors and fuel system tomorrow. Is it possible that the cam or crank sensors could be bad?
Expert:  Mastertech 1 replied 11 months ago.

Possible, But more then likely it has low fuel pressure causing the issue. Thank-you, Have a Merry Christmas!

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