'03 GT Cold Hesitation

03stang

New Member
Sep 7, 2002
25
0
1
E. PA
I've got a 2003 GT, w/ 5 spd. that can't get out of its own way :mad: when I jump in it and try to go from totally cold startup. It just sputters almost as if it isn't getting either any fuel or spark :scratch: . It kind of acts like when the annoying T.C. kicks in, except, when this happens, I can't get the revs. up high enough to even think about wheelspin :bang: . This goes away after I run it for like 30 sec. to less than a minute, and then it's fine :) .

I've just changed over to Autolite 764's w/ 054 gap, but the car still acts up when cold :mad: . The 764's seem to help rev. better up through to redline, and it even makes a deeper rumble :nice: .

My only mods. are Magnaflow X-Pipe, and Magnaflow Catbacks. I run 87 octane pump gas, which seems to work fine and Amsoil 5w20. I appreciate any input my fellow Stangers may have, and here's to the one and ONLY PONYCAR!! :cheers: :flag: :flag: :hail2: :hail2: :cheers:
 
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I have the same problem on my 02. And i run 93 octane. my timing adjust helped a little for some reason. I have been to the dealer about 10 times trying to fix the problem and all they do is adjust the base line idle. Which doesn't do anything. One of my buddies say it might have something to do with the throttle positioning sensor but who knows. i just let my car warm up first for a minute or two and it's fine. Wish i could help you more.
 
For one thing, if you cant wait around for 30 seconds or so for your car to warm up, you may need to set your alarm a bit earlier :D . Im just picking man, do you notice any hesitation or anything at start up, or is it just when you hit it, its not responding?
 
When I first fire mine off it is kinda sluggish. If I rev it up a little it will kinda spit and spuder a little but its done that since day one. I figure it just like to heat up a little before you tear the back tires off. I had a 65 Mustang that did that, it would die if u didn't let it warm up so im used to it i guess.
 
StangLou said:
For one thing, if you cant wait around for 30 seconds or so for your car to warm up, you may need to set your alarm a bit earlier :D . Im just picking man, do you notice any hesitation or anything at start up, or is it just when you hit it, its not responding.

Well, I admit that I'm one of the most impatient people around...No problem at start up, if I just fire it up and let it idle. It bogs really bad when I hit the throttle.
 
StangLou said:
Have you oiled your air filter recently or just a put a new one on? Maybe some oil is trapped in your mass air meter :shrug:

That's a good question. Actually, I still have the factory filter in it. The car has almost 11,000 miles on it, and I was going to put in my company's K & N competitor. I'm an engineer working in the filtration industry....
 
Your not making this easy :D

It wouldnt hurt to take apart the assembly to check and see if the mass air meter has anything gumming it up that might have slipped past the filter.

Other then that man Id lean towards the plugs being an issue but you just changed them :shrug: . How tight did you make the plugs by chance. Just a 1/8 turn past finger tight is all you need. Im running out of ideas here :banana:
 
StangLou said:
Your not making this easy :D

It wouldnt hurt to take apart the assembly to check and see if the mass air meter has anything gumming it up that might have slipped past the filter.

Other then that man Id lean towards the plugs being an issue but you just changed them :shrug: . How tight did you make the plugs by chance. Just a 1/8 turn past finger tight is all you need. Im running out of ideas here :banana:

I wish that I could make this easier, but I didn't torque the plugs very tight, understanding the deal with aluminum heads. Also, the car acted the same way with the factory plugs. I'll add that the factory plugs looked fine. None were any wetter or drier, or any different color from the other.

I'll take a look at the mass air meter when I change the filter--probably this weekend, though I did want to install my Steeda sport springs and U/D pullies. So many things to do, and weekends are so short... :shrug:

I very much appreciate you spending the time here. I have considered going back to the dealer, but would like to try and figure it out in the "backyard" first. :scratch:
 
I think any car benefits from at least a little warm up, eh?? My car has been doing that since day 1 also...02 gt with 30, 000 miles on it now.....However when i do need to just start and go, i just wait a minute or two down the road before i push it.
 
Had the same problem with my 01 GT. Drove like a SOB when cold - worst cold driving new vehicle I've had. Ford dealer said its normal - ya right and donkeys can fly.

Replaced the throttle body recently with a Ford 70mm.

Problem gone - could be coincidence or maybe the Motorsport unit has a better throttle position sensor in it.
 
allutz said:
I think any car benefits from at least a little warm up, eh?? My car has been doing that since day 1 also...02 gt with 30, 000 miles on it now.....However when i do need to just start and go, i just wait a minute or two down the road before i push it.

Points well taken...I know that something just isn't right here. I would expect this thing to act up if it had a carb, and choke, but it literally can't get out of the way. Oh yes, I remember Dad reminding me to try to at least let the heads get lukewarm. I always was a rebellious one... :D
 
CanuckMustang said:
Had the same problem with my 01 GT. Drove like a SOB when cold - worst cold driving new vehicle I've had. Ford dealer said its normal - ya right and donkeys can fly.

Replaced the throttle body recently with a Ford 70mm.

Problem gone - could be coincidence or maybe the Motorsport unit has a better throttle position sensor in it.

Yours is an interesting point, too. I have been contemplating a Motorsport T.B. anyway, in anticipation of adding a turbo, or blower...Power adders are another story...Thank you! :canflag:
 
I vote for the TPS adjustment, too -- and a trip to the dealer to have them sort it out. My '03 GT only has 1250 miles on it (only a month old :) ), but it's never even hinted at bogging, stone cold or otherwise, so yours isn't "normal."

BTW, I completely understand the desire to have throughly diagnosed the problem before you take it in (I'm *exactly* the same way) -- but you need to at least get a "baseline" diagnosis from the dealer to confirm that everything is/is not in spec, before the speculation as to possible causes drives ya batty. Just my $0.02.
 
My '02 does it too. I like nothing better than stepping out the rear end as I leave the parking garage after a hard day's work. Nothing doin' unless I rev the engine before heading out. Kinda embarassing to lay into it and have it bog.

Just changed out the factory air filter for a Holley power-shot. No difference in the bogging. It does seem to rev quicker once warmed up though.

As far as the 70mm TB, what is the stock TB for an '02? I thought of upgrading to 70mm but thought that it was stock on the '01.5 and up - like the 3650 tranny swap.
 
my 03 does the same thing, seems to be a little sluggish when stone cold but when it warms its fine.
just give it a good 30sec- 1 min to warm, rev it a bit, and you should be fine. all my cars have done that (bogged when cold)


ciao
 
I have an '02 Gt 5 spd. and at start up it has this weird misfireing sound like a put put put put. It's hard to explain but, it sounds like pulses of air coming out of my exhaustand engine. When it would do that I would have to rev it a few times then it idles normal. But, yesterday I started her up after not being turned on for 3 or 4 days and it did it again right after start up at idlef or about 30 sec's and I freaked out and turned her off. I was like WTF is this ****, it's doing it again. So, I started her up again right away and it didn't do it again. Does anyone know what is causing this? What is a AIC? Could it be that? I had to ask since I was reading this thread. But, mine is at start-up when idleing.
 
StangLou said:
Your not making this easy :D

It wouldnt hurt to take apart the assembly to check and see if the mass air meter has anything gumming it up that might have slipped past the filter.

Other then that man Id lean towards the plugs being an issue but you just changed them :shrug: . How tight did you make the plugs by chance. Just a 1/8 turn past finger tight is all you need. Im running out of ideas here :banana:

I'm curious to see if you plan on running your car on the dyno with the Diablo chip. If you already have, what are the #'s? :cheers: