# Problems on Startup - Car Stutters **URL:** \ **Category:** NYSpeed Automotive\ **Created:** [April 11, 2007, 3:51pm UTC](https://forums.speedlife.net/t/problems-on-startup-car-stutters/27473 "2007-04-11T15:51:48Z")\ **Posts on this page:** 17\ **Page:** 1
**Author:** ![jetlounge](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/jetlounge/32/4994_2.png) [@jetlounge](https://forums.speedlife.net/u/jetlounge)\ **Post date:** [April 11, 2007, 3:51pm UTC](https://forums.speedlife.net/t/problems-on-startup-car-stutters/27473/1 "2007-04-11T15:51:48Z")
Two days in a row I have noticed startup problems. In the morning, cold enough that there is frost on the windshield and the car is left all night…asolutely no problems with startup. But drive to work, leave the car in the sun all day (about 55 degrees today i think), then go out and when i turn the key, the engine stutters for about 10 seconds before it kicks over…it feels like it wants to die or can’t quite get above 300 rpm…but eventually does. The stutter is in the engine, not like the electrical stutter when my battery is dead…although what the hell do i know…that’s i’m asking for help. things i have done that may/may not contribute: supercharger, 10w30 oil, iridium spark plugs. while none of those are new…the s/c was added in december…so i guess this is the first real stretch that the car and mods have seen warm weather…if that is the issue at all. Anyway, in the lot i let the car warm up today after the stutter start. Shut it off, and rekeyed the ignition…starts up with no problems. So why doesn’t it like my office parking lot at 5pm on the first shot? ---
**Author:** ![brent\_strong](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/brent_strong/32/7203_2.png) [@brent\_strong](https://forums.speedlife.net/u/brent_strong)\ **Post date:** [April 11, 2007, 3:53pm UTC](https://forums.speedlife.net/t/problems-on-startup-car-stutters/27473/2 "2007-04-11T15:53:39Z")
Losing fuel pressure over night maybe? Have you tried cycling the key on and off a couple times to build up fuel pressure and then trying to start it? ---
**Author:** ![jetlounge](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/jetlounge/32/4994_2.png) [@jetlounge](https://forums.speedlife.net/u/jetlounge)\ **Post date:** [April 11, 2007, 4:06pm UTC](https://forums.speedlife.net/t/problems-on-startup-car-stutters/27473/3 "2007-04-11T16:06:44Z")
but it’s fine overnight…it only stutters in the afternoon when it is warmer. i will try the cycling though tomorrow. how do you lose fuel pressure/correct it? ---
**Author:** ![Justin](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/justin/32/7459_2.png) [@Justin](https://forums.speedlife.net/u/Justin)\ **Post date:** [April 11, 2007, 4:52pm UTC](https://forums.speedlife.net/t/problems-on-startup-car-stutters/27473/4 "2007-04-11T16:52:03Z")
What kind of car is this? ---
**Author:** ![jetlounge](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/jetlounge/32/4994_2.png) [@jetlounge](https://forums.speedlife.net/u/jetlounge)\ **Post date:** [April 11, 2007, 4:53pm UTC](https://forums.speedlife.net/t/problems-on-startup-car-stutters/27473/5 "2007-04-11T16:53:06Z")
scion tc. ---
**Author:** ![jetlounge](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/jetlounge/32/4994_2.png) [@jetlounge](https://forums.speedlife.net/u/jetlounge)\ **Post date:** [April 12, 2007, 6:58am UTC](https://forums.speedlife.net/t/problems-on-startup-car-stutters/27473/6 "2007-04-12T06:58:50Z")
any other thoughts? ---
**Author:** ![brent\_strong](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/brent_strong/32/7203_2.png) [@brent\_strong](https://forums.speedlife.net/u/brent_strong)\ **Post date:** [April 12, 2007, 6:59am UTC](https://forums.speedlife.net/t/problems-on-startup-car-stutters/27473/7 "2007-04-12T06:59:50Z")
Poor calibration for whatever the unit is that provides extra fuel for the supercharger? ---
**Author:** ![Dr.Stevil](https://avatars.discourse-cdn.com/v4/letter/d/da6949/32.png) [@Dr.Stevil](https://forums.speedlife.net/u/Dr.Stevil)\ **Post date:** [April 12, 2007, 9:56am UTC](https://forums.speedlife.net/t/problems-on-startup-car-stutters/27473/8 "2007-04-12T09:56:44Z")
try priming the pump before starting it next time… see if that helps ---
**Author:** ![jetlounge](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/jetlounge/32/4994_2.png) [@jetlounge](https://forums.speedlife.net/u/jetlounge)\ **Post date:** [April 12, 2007, 3:51pm UTC](https://forums.speedlife.net/t/problems-on-startup-car-stutters/27473/9 "2007-04-12T15:51:43Z")
priming seemed to help today. so, what does that mean? ---
**Author:** ![Dr.Stevil](https://avatars.discourse-cdn.com/v4/letter/d/da6949/32.png) [@Dr.Stevil](https://forums.speedlife.net/u/Dr.Stevil)\ **Post date:** [April 13, 2007, 5:45am UTC](https://forums.speedlife.net/t/problems-on-startup-car-stutters/27473/10 "2007-04-13T05:45:05Z")
could mean a few things… the motor doesn’t seem to get enough fuel on startup. what blower are you running? was it a kit, or did you piece it together? are you running upgraded fuel injectors? pump? how many miles on the car? still on original fuel filter? Was the car tuned for the kit, or is it running on a cookie cutter tune that came with the SC? ---
**Author:** ![jetlounge](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/jetlounge/32/4994_2.png) [@jetlounge](https://forums.speedlife.net/u/jetlounge)\ **Post date:** [April 13, 2007, 6:49am UTC](https://forums.speedlife.net/t/problems-on-startup-car-stutters/27473/11 "2007-04-13T06:49:59Z")
This is what I have: Vortech S/C V-5 F-TRIM , kit provided and sold under the TRD brand. No piggyback, TRD reflashes the ECM with an updated map on install. Injectors get upgraded in the kit (410cc), but not fuel pump. About 18k miles now. I would imagine the fuel filter is still original at this point. This is a link to the kit install with parts list if that helps: [http://trdsparks.com/install/PTR01-21050-90inst.pdf](http://trdsparks.com/install/PTR01-21050-90inst.pdf) Only thing i have changed is to iridium spark plugs and Forge BPV. some scion tuners have upgraded to 550 injectors/walbro pump/emanage…but i think that was after pushing over 285 to the wheels. i think that was to alleviate issues at wot, not startup. and i am not near that whp number anyway. Thanks for the help. Also, I am still puzzled why it seems more symptomatic in warmer weather. ---
**Author:** ![Dr.Stevil](https://avatars.discourse-cdn.com/v4/letter/d/da6949/32.png) [@Dr.Stevil](https://forums.speedlife.net/u/Dr.Stevil)\ **Post date:** [April 13, 2007, 7:17am UTC](https://forums.speedlife.net/t/problems-on-startup-car-stutters/27473/12 "2007-04-13T07:17:25Z")
your right… it really shouldn’t matter at idle… I’m just wondering if you may have been overworking your stock pump and possibly it’s getting goofy on ya (which I somewhat doubt). I’d honestly start with the fuel filter and see what happens ---
**Author:** ![jetlounge](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/jetlounge/32/4994_2.png) [@jetlounge](https://forums.speedlife.net/u/jetlounge)\ **Post date:** [April 13, 2007, 11:56am UTC](https://forums.speedlife.net/t/problems-on-startup-car-stutters/27473/13 "2007-04-13T11:56:16Z")
when you say “overworking”…ok, i am a bad boy…i let the fuel go to 1/8th tank often before fueling. is that what you mean? and now i am reading that the pump is cooled by gas…so it is possible that it gets damaged sooner. although i have always driven cars like that and i’m sure i’m not the first. ---
**Author:** ![boardjnky4](https://avatars.discourse-cdn.com/v4/letter/b/96bed5/32.png) [@boardjnky4](https://forums.speedlife.net/u/boardjnky4)\ **Post date:** [April 13, 2007, 12:20pm UTC](https://forums.speedlife.net/t/problems-on-startup-car-stutters/27473/14 "2007-04-13T12:20:53Z")
u really should upgrade ur fuel pump to a 255 walbro pump. In general starting a car requires a bit more pressure then once its started. ---
**Author:** ![jetlounge](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/jetlounge/32/4994_2.png) [@jetlounge](https://forums.speedlife.net/u/jetlounge)\ **Post date:** [April 13, 2007, 1:21pm UTC](https://forums.speedlife.net/t/problems-on-startup-car-stutters/27473/15 "2007-04-13T13:21:22Z")
so start with the filter and if that doesn’t work, upgrade the pump? walbro 255 standard or high pressure? ---
**Author:** ![boardjnky4](https://avatars.discourse-cdn.com/v4/letter/b/96bed5/32.png) [@boardjnky4](https://forums.speedlife.net/u/boardjnky4)\ **Post date:** [April 13, 2007, 1:39pm UTC](https://forums.speedlife.net/t/problems-on-startup-car-stutters/27473/16 "2007-04-13T13:39:44Z")
high pressure ---
**Author:** ![jetlounge](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/jetlounge/32/4994_2.png) [@jetlounge](https://forums.speedlife.net/u/jetlounge)\ **Post date:** [April 23, 2007, 5:31pm UTC](https://forums.speedlife.net/t/problems-on-startup-car-stutters/27473/17 "2007-04-23T17:31:56Z")
ok so this past week as the weather warmed up I tried a few things. 1 - Swapped the EFI relay to ensure it wasn’t bad 2 - Dumped in some STP fuel system cleaner to kill any possible debris plugging the filter Thought I was in the clear but when it was warm on Saturday, the car choked on startup again. This time much worse then before. So next, I 3 - Checked the spark plugs. My Iridiums I was told we pregapped to .035" so I just dropped them in 2 months ago, but i pulled them out and measured them at about .030". This is smaller than the .032" the stock plugs call for. Long story longer, I extended the gap to .036"… Today was very warm…hit 80 degrees…car sitting outside for hours and NO problem at startup. Am I wishfully thinking that I solved my problem? Could 5/100th of an inch matter that much??