Hard start

Discuss any problems, warranty, repair, or replacement issues you are having with your Vibe & Matrix
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Autotech309
Posts: 1
Joined: Fri Nov 17, 2017 12:17 pm

Hard start

Post by Autotech309 »

My name is Andrew I own a 2003 Pontiac Vibe 1.8 2wd. I have two issues my biggest is I have a hard start issue when the car is warm. I have check spark plugs, fuel pump I also looked for air leaks I just can’t figure it out it’s only when the car is warm and the more I drive it the worst it gets. I have 246,000 miles with no check engine lights and and Maintence has been kept up with oil changes spark plugs things like that. I go to school for automotive technology and I’m just stumped. I’ve went through the process of elimination and just can’t figure it out. Any and all responses are welcome.
andrewclaus
Posts: 482
Joined: Tue Oct 03, 2017 6:38 pm
Location: Golden, CO

Re: Hard start

Post by andrewclaus »

Maybe a leaky fuel injector (too much fuel), or a fuel delivery problem when hot (too little fuel).

Try a fuel pressure gauge on the hot engine, try some injector cleaner. Then try replacing injectors maybe one at a time if you can't afford all or can't test them at school.
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vibrologist
Posts: 1598
Joined: Sat May 10, 2014 8:24 am
Location: Iowa

Re: Hard start

Post by vibrologist »

Maybe the PCM recall was not performed on yours. Check that before you consider a career change. Just kidding.... :)
Vibrologist
'05 Vibe

"It is important to know the difference between 'accurate' and 'precise' even if you are neither!"

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jolt
Posts: 945
Joined: Sun Mar 02, 2014 2:07 am
Location: Twin Cities, Minnesota

Re: Hard start

Post by jolt »

Compression test, cylinder leak down test, coolant leak pressure test, coil packs degrade with heat? Cold starts are fine? Valve clearance has been checked?
lannvouivre
Posts: 1601
Joined: Thu Jun 09, 2011 1:00 pm
Location: Texas yay

Re: Hard start

Post by lannvouivre »

There was a TSB for the 1.5 generation vibes for hard start when engine is hot. It involves a PCM reflash. I can no longer access that information because that **** costs money, but you should be able to through prodemand etc. via for school. This TSB may not involve the '03-4 models.

HOWEVER, you may also try testing for a drop in fuel pressure after the ignition is shut off, just because it is also something that causes similar issues. I think that's probably not your problem and it's instead the PCM's programmed tuning, but for the sake of sharing some related info I'm going to vomit it all over your thread.

The Toyota fuel pumps hold residual pressure on the fuel rail with an integral diaphragm inside the pump itself. This is to prevent you having to prime the pressure again before starting. It should hold the pressure for several hours, so you hook up a pressure tester, run the car, turn the car off, record the pressure, take off for a few hours, and then recheck. The pressure should not fall.
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