Hard to start and poor throttle response

1.8-liter VVTL-i (2ZZ-GE) and VVT-i (1ZZ-FE) engine, transmission, exhaust, intake, and performance tuning discussions
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2006
Posts: 43
Joined: Mon Jul 23, 2018 9:01 am

Hard to start and poor throttle response

Post by 2006 »

My daughter's 06 had an issue this morning. It was hard to start, and when running the idle was alright, but when you blipped the throttle it stumbled before it would increase. It also stalled while attempting to drive. There wasn't a code initally, but eventually PO171 (bank 1 lean) came in. I swapped out all 4 coils with Vibe #2 which did not change anything, and Vibe #2 ran fine with the swapped out coils.

I figured an intake manifold gasket is cheap and easy, so I just replaced that. It was quite flat so I thought that would be it. It was only a Fel-Pro gasket.....might not be as good as a factory Toyota one, but at least it's new and should perform adequately for a while at least. Nothing has changed....I have double-checked all vacuum lines and connections.

The air filter is new, MAF was cleaned and plugs have been replaced recently, as well as the fuel pump (Denso). Injectors perhaps?

Any guidance would be greatly appreciated as always.

Thank you in advance,
Paul
Mark
Posts: 660
Joined: Sun Nov 02, 2008 7:26 am
Location: Cheyenne, WY

Re: Hard to start and poor throttle response

Post by Mark »

Bad gas maybe? You could try some Heat or other fuel dryer maybe, and check/replace the fuel filter. Sorry, I can't think of anything else that you haven't already covered.
'08 Base Stealth, '05 Base Satellite
andrewclaus
Posts: 526
Joined: Tue Oct 03, 2017 6:38 pm
Location: Golden, CO

Re: Hard to start and poor throttle response

Post by andrewclaus »

Yes, injectors. Start by cleaning. I've had good luck with BG-44K.

Fuel pressure?

Since it's idling okay, I wouldn't suspect vacuum leak. You can try a gauge.
jolt
Posts: 956
Joined: Sun Mar 02, 2014 2:07 am
Location: Twin Cities, Minnesota

Re: Hard to start and poor throttle response

Post by jolt »

Fuel pressure or fuel volume problem possibly. Bad fuel pump or fuel pressure regulator? Fuel line pinched under car? Test fuel pressure and volume by injectors. Do a search on this board as there was a post on how to make a tester hose for the first gen Vibe.

A jumped timing chain can make a engine run like that too, but you would not be getting the lean code from that so test your fuel supply first and go from there.
2006
Posts: 43
Joined: Mon Jul 23, 2018 9:01 am

Re: Hard to start and poor throttle response

Post by 2006 »

Well......it was definitely fuel related! I pulled out 1 injector to see what kind of pressure was there, as I have no pressure gauge set-up. I was surprised to not even get the slightest squirt of fuel as I removed the injector....and the fuel rail wasn't even full. I popped the injector back in and removed the fuel pump.

The clips on the strainer assembly were undone at the regulator, and the regulator had moved out of the assembly buy about 1/4", and the oring was starting to stick out in one area. I popped the regulator back in, and locked that section of the strainer assembly into place to secure the regulator in place. Dropped the pump assembly back in and it fired up. Of course it did need a bit of cranking to ompletely fill the line/fuel rail.

I just I'd pass along what had happened, as it may be of some help to someone, some day.
Paul
zbyers
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Joined: Thu Apr 03, 2014 6:12 pm
Location: Sheffield, Pennsylvania

Re: Hard to start and poor throttle response

Post by zbyers »

Glad to hear it a was a pretty simple fix!
'74 Thing, '79 El Camino, '83 VW DoKa '91 Vanagon, '03 Base, 04 GT
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2006
Posts: 43
Joined: Mon Jul 23, 2018 9:01 am

Re: Hard to start and poor throttle response

Post by 2006 »

Definitely nice when it's an easy fix....and cheap. :D It did waste a lot of my weekend messing around with it though.
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