Hard to start in the mornings

Michael10101 · 09-22-2009, 07:13 AM

Over the past 2 weeks my GXP with the GMPP has been having increasing more and more difficult starting. At first it was nothing, an occasional rumble when I started her up, but that has progressed to a rumble every time, to now she has major problems starting up. Well... what I think are major.

This morning it took three attempts to get her started. The first time just sounded like the starter was trying to get it to turn over, but she wouldn't so I cut the ignition. The second time she sputtered a few times then died on her own. The third time she turned over and ran but for about 20 seconds I was getting a lot of noise and engine shakes.

I've posted a video on you tube, any ideas?

YouTube - Hard morning start

R&T · 09-22-2009, 08:21 AM

That stinks. I was contemplating getting the GMPP tune but seems like more people are having problems with their sols after getting this done. Maybe it is just me.

As for your question. The last time I had a car that started like that (carb'd) it was a fuel delivery problem. I had to rebuild the carb. From the video it sounded just fine when you where giving it gas. That leads me to believe it isn't getting enough fuel and you didn't mention the CEL on after it started to run or since you have been having this problem over the last week or so. Usually after a couple of miles or minutes of operating if a sensor is bad it will throw a code.

Take this with a grain of salt as I don't know how the computer is reprogrammed with this tune. May not have anything to do with fuel and a sensor is going bad, just not bad enough to throw a code.

You could also have some bad gasoline. Water in a DI fuel system is hell.

Gunnys GXP · 09-22-2009, 11:21 AM

I was going to say water as well but also may be the spark plug issue creeping up. A TSB came out to upgrade to a hotter burning plug due to fowling of the originals. Way want to look into that as well. Pull a plug and see if it is all clogged up. they may have been fine for the stock tune but not hot enough for the GMPP tune.

reedred · 09-22-2009, 05:56 PM

I often am too.

GS Stage 1 · 09-22-2009, 09:04 PM

Michael, I have had the GMPP tune in for about a year. My car has been a problem child with several different issues. However, with the possible exception of some questionable 3 bar sensors they changed out, none of my issues have been directly related to the GMPP tune. But the tune may accelerate other failures that were coming your way anyway. A good example of this on my car, was the IC going bad (mushroomed). Between a combination of that and a leaky Throttle Body clamp, I too was having starting and cold idle issues almost identical to your video clip. Here is a link to my thread: GMPP Tune and P0101 code.

There is a lot of good information in that thread, for various issues. I am betting one of two things: Either you have questionable plugs (but if the plugs are bad enough to cause colds start issues, I would expect you to be noticing misfires during driving) Or you have a leaky throttle body clamp. Mine was leaking enough that it was sucking extra air though the clamp on cold start and causing turbulence in the intake and lien conditions. After it would warm up, it would idle normally, just like your video. And the mushroomed IC was causing crazy turbulence, resulting in CEL and limp mode. The only other thing I can think of is possible fuel pressure issue. You may be getting a fuel pressure bleed down after sitting and it is starving for gas on cold start. Start with the simple things, inspect the throttle body clamp and IC and plugs.

Michael10101 · 09-22-2009, 11:10 PM

Well, I took it in to the dealer this evening so they could take a look at her in the morning. We'll see what they say. GS, I read your thread on the P0101 and I had a lot of similarities. I've not gone into the "limp mode" yet, but I have felt like she wasn't moving like she had in the past. And I did have a few episodes when the boost didn't seem to register the way it had previously, which I chalked up to just not looking down at the right moment. We'll see what the dealer has to say, but regardless I'm going to change out those clamps.

I love my car, but it pisses me off to no end that in 3266 miles, I'm already having to take it to the dealer for problems. But I've still got 57 months or 66,734 miles before the drive train warrenty goes out. And I'd still buy another one if I could.

Michael10101 · 09-23-2009, 10:06 AM

Well, I heard back from the dealer, and..... leaking fuel injectors. The parts have been ordered and will be in in about a week.... Till then, hard morning starts. How embaressing.

Gunnys GXP · 09-23-2009, 04:58 PM

Quote:

Originally Posted by Michael10101

Well, I heard back from the dealer, and..... leaking fuel injectors. The parts have been ordered and will be in in about a week.... Till then, hard morning starts. How embaressing.

Interesting. First I've heard of that one for any of the cars running Ecotec LNF. Congrats on being the first. No, I'm kidding of course.

Glad they're getting it figured out, will have it fixed, and is not a major issue.

Mac · 09-23-2009, 09:29 PM

I do not think there is a alot of issues with the upgrade, excepting the need for better fuel. I have had the tune as soon as it came out for the 08's. Fact is no other mod will make any power with out a tune that turns the learn down off, be it GM or wester etc. The hose clamps used in lue of a T type is going to fail with or with out the tune. VERY FEW IC have ballooned.

Parts fail its part of life.

mena661 · 09-23-2009, 10:27 PM

Quote:

Well, I heard back from the dealer, and..... leaking fuel injectors.

I had a hard start problem a while ago that turned out to be a bad low pressure fuel pump.

MGar · 09-24-2009, 01:46 AM

I've also heard hard starts being caused by a failing EVAP solenoid. A quick way to diagnose that is to open the gas cap before you start in the morning. If that resolves the issue, and it starts easy, it's more than likely an EVAP issue.

GS Stage 1 · 09-24-2009, 10:31 AM

The EVAP solenoid failing will cause hard starts on HOT starts, and right after filling the gas tank. Been there, done that.

The car would start normally during cold starts in the morning. And yes, opening the gas cap will get it running.

The "leaky injectors" diagnosis is interesting. That definitely falls into my third idea of pressure bleed down after sitting.

I1ULUZ · 09-26-2009, 06:46 AM

IF you get the car back and it's still doing the same thing. One morning before you try to start it pull the plugs and see if they are wet with gas. Also pull the dipstick out and sniff it, if the injectors are leaking down then the gas is going some place and the oil pan is the place to hang out, the oil will smell like gas.

I am betting they are not. If the injector can withstand the combustion pressure I am sure it's not leaking down just sitting there with no fuel pressure on it.

R&T
FYI depending on the condition check engine lights can take up to the 3rd time to be seen before they turn on.

Michael10101 · 09-26-2009, 10:10 AM

Since I've gotten it back from the dealer when he did the initial assessment, the starts have been significantly better, but still having some symptoms of running lean. I'll let yall know how she does once I get her back after the installation of the new injectors sometime next week.

I'll check the spark plugs for cracks and fluid tomorrow, and the dipstick for a gas type smell at the same time. Hope the neighbors don't see me smelling the dip stick. They'll think I'm crazy.... I mean it'll just re-enforce the idea that I'm crazy.

Michael10101 · 10-08-2009, 04:13 PM

So, the injectors FINALLY came in two days ago. I dropped the car off. That day they called me later and said that they didn't realize they also needed a gasket that had not been ordered. Well the gasket came in and low and behold, they needed two more parts that weren't in stock. Some clips for the injectors, and a high pressure hose.

Here comes the fun part....

GM has none. When will they have some available you ask? The dealer doesn't know. A week, a month, maybe longer. This unreal. Is this what I have to look forward to if I need a part in the future? UGH!!!!