Hard to start and poor throttle response

[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]

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.

[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]

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]

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]

Glad to hear it a was a pretty simple fix!

[2006]

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