Issues When Starting In The Cold

**surfinjoe** · 01-22-2009, 10:52 AM

A few times this winter, I have had issues when starting my car when it's cold outside. I turn the key and it will turn over but won't start. It seems to catch, then stalls in 1/2 a second. I crank it again and the same thing happens. Then I crank it again giving it full throtle (like in the old carb. days) and it starts, but runs rough for about 20-30 seconds, then everything is fine.

I don't know if it's just coincidence, but the day before this happens (at least the past 2 times) I notice that the temp. gage falls all the way to cold (while driving down the road & after the engine is warm) for about 15-20 seconds then returns to the correct temp.

Very strange....anyone have any ideas?

I am thinking that she may need a tune-up, new fuel filter and some Seafoam.

BTW - my car is an 04 w/ 24K miles.

**Sarge** · 01-22-2009, 12:36 PM

Look at your throttle blade and tell us if it is closing all the way. Often the blade gets crap all in it and wont close all the way and causes this exact issue.

**qwkgto** · 01-22-2009, 02:46 PM

Originally Posted by surfinjoe

A few times this winter, I have had issues when starting my car when it's cold outside. I turn the key and it will turn over but won't start. It seems to catch, then stalls in 1/2 a second. I crank it again and the same thing happens. Then I crank it again giving it full throtle (like in the old carb. days) and it starts, but runs rough for about 20-30 seconds, then everything is fine.

I don't know if it's just coincidence, but the day before this happens (at least the past 2 times) I notice that the temp. gage falls all the way to cold (while driving down the road & after the engine is warm) for about 15-20 seconds then returns to the correct temp.

Very strange....anyone have any ideas?

I am thinking that she may need a tune-up, new fuel filter and some Seafoam.

BTW - my car is an 04 w/ 24K miles.

when was the last time you changed your spark plugs? also check the gap.car wants to run richer in colder weather ,because of more moisture in air, gap might need shortened..

**GTO1_OHIO** · 01-22-2009, 02:55 PM

Another thing with the TB is ...Make sure a screw hasn't backed its way out...I had the same cold start problem a few years ago until we found that.

**0rion** · 01-22-2009, 08:21 PM

I doubt the temp sender is what's doing it. I've seen those go bad and the car will start fine in open loop then drown itself in gas as soon as it goes to closed loop. The 04's are known to have gauge quirks and depending on how long you're having to crank it you could be about halfway draining the battery too which could give you some electrical quirks.
The fact it's running rough after it starts almost makes me think it's flooding a little bit. How many miles on it and your plugs? Might want to at least pull a plug and give it a look see. Do like these guys recommended and check that throttle body and plugs out.

**surfinjoe** · 01-23-2009, 05:32 AM

Thanks for all the feedback. I will change the plugs as they have 24K on them. I will also look at the throttle body and see if there is come crap build up. I don't have a catch can yet, so maybe I have an oil build-up as well. Last time this happened, I dumped a bottle of Seafoam in her and it fixed the problem.

I also un-installed the tune that I had (Diablo) and that seemed to make it run better (even seemed to have more power).

Does anyone have any plug recomendations? I am leaning towards iridium, but am open to anything.

**Sarge** · 01-23-2009, 07:37 AM

NGK TR6's or 55's depending on mods......

**surfinjoe** · 01-23-2009, 07:55 AM

My motor is stock on the inside....just bolt-on's. Would TR6's be my best bet Sarge?

Originally Posted by Sarge

NGK TR6's or 55's depending on mods......

**0rion** · 01-23-2009, 08:21 AM

tr6's is a cold plug for spray or forced induction.......go with tr55's. 24k is not very many miles though. I would pull a couple and inspect them to see what they look like. Do you have any tune on the car with the diablo at the moment?

**surfinjoe** · 01-23-2009, 08:24 AM

I just went back to stock tune last night....seemed to run better (with more power even) with the stock tune....at least in the cold.

I previously had the 'NASCAR' tune. It kind of made my car start funny, even in the warm. Do you have another tune in mind for a stock motor w/ bolt on's (catback & CAI)?

Originally Posted by 0rion

tr6's is a cold plug for spray or forced induction.......go with tr55's. 24k is not very many miles though. I would pull a couple and inspect them to see what they look like. Do you have any tune on the car with the diablo at the moment?

**0rion** · 01-23-2009, 08:47 AM

it sounds like the tune could have been your issue, give it a few starts for the idle to relearn and see if that was if fact your issue. On a stock or bolt on car there's really not a ton of changes necessary. You want to get your LTFT's near zero and lean out wot to 12.8:1 air fuel ratio and that's about it. The data kinda dictates where you go with the tune. Do you have the newer diablo version that lets you log data? If you do start with part throttle and cruise around logging LTFT's then adjust your fueling to where those are all at or near zero. Then do some wot runs and log your O2 voltages and adjust fuel to get those in the .880-.890 range. A wideband is definitely preferred instead of using O2 voltages especially if you have headers. You can ball park it with the voltages though.

**surfinjoe** · 01-26-2009, 09:05 AM

I will re-tune when it gets a little warmer :-) Thanks for the info. She seems to be running better now with the stock tune. I'll let you guy's know if she starts running like sh*t again.

Originally Posted by 0rion

it sounds like the tune could have been your issue, give it a few starts for the idle to relearn and see if that was if fact your issue. On a stock or bolt on car there's really not a ton of changes necessary. You want to get your LTFT's near zero and lean out wot to 12.8:1 air fuel ratio and that's about it. The data kinda dictates where you go with the tune. Do you have the newer diablo version that lets you log data? If you do start with part throttle and cruise around logging LTFT's then adjust your fueling to where those are all at or near zero. Then do some wot runs and log your O2 voltages and adjust fuel to get those in the .880-.890 range. A wideband is definitely preferred instead of using O2 voltages especially if you have headers. You can ball park it with the voltages though.