Good morning everyone,

So I did a search on this forum to find out if anyone else has start-up issues with their tC and it seems like most people who have start up problems have variables of which does not apply to my situation (modded intake, live where it snows, etc). I am having this weird start-up problem with my car, and I would appreciate any advice or suggestion. I apologize in advance for the long post.

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This is my situation:

I have a 2006 Scion tC, automatic transmission, came factory with TRD exhaust and dealer-installed Karlock security system. Current mileage is 50,000 (for most of its life it was a leisure car). I only get Chevron 87 gas (although the occasional Mobil/76/Shell when Chevron is not around). Located in southern California.

About a year ago my battery was starting to show signs of dying (1-2 incidences where I had to try more than once to start the car, but I was able to start the car ultimately no problem, driving was normal). My mechanic dad added some water to the battery as a temporary fix although warned that my battery would need to be replaced soon. This held me over for a year.

Last Tuesday 8/2
My car battery died near an Autozone (lucky me) so I replaced it with a new Duralast 24DL battery (one of the Autozone guys helped me install it). Immediately after installing the battery, car was able to start fine although my passenger side window wouldn't work when controlled from the driver side. After 10 minutes, window worked (the Autozone guy said the computer system needs to reset itself after the new battery installation). So I went home, driving was normal. That was the last time I will see my car start normal. I had to go out again so when I started my car, it "coughed" and struggled to start before it would turn over.

Last Wednesday 8/3
Going to work and coming back, all the times I started the car it would cough and struggle to start before turning over - sometimes taking 5-7 times to succeed. After just starting 1-2 times, the starter feels very hot. Mechanic dad suspects it's a starter problem so I got a new one from Autozone and installed it. Checked the battery connections, everything is tight and good. With the new starter in, the car still coughs and sometimes struggles to start before turning over although now it takes fewer tries to succeed - there were even a few times that it starts normally! But because it was still coughing, we drove the car to Autozone for them to check the battery and starter just to be sure (what are the chances that the parts they gave us was not 100% functional?). The battery was found to be good. He didn't test the starter but said he suspects its an ignition problem. Because the quality of the start-up is infrequent, I thought the new starter just needed to be broken in so dad recommend to drive it around a few days to see if it will get better and watch for symptoms. After 2 days of driving, my maintenance light turns on (great), still coughing, so I decide to take it into Toyota dealership to get it looked at.

Saturday 8/6
I take the car in to dealership for oil change and unfortunately they did everything without even mentioning to me that there was a start-up problem. I didn't want to do the diagnostic test yet ($110, so expensive!) so I spoke with the service manager to get some guidance on what MAY be the problem. He suspects the starter even though I just replaced it, suggesting that Autozone may have given a faulty one. What if I do the diagnostic test and they suggest a new starter? Am I suppose to just buy another one?? I decided not to do the diagnostic and drove home. Dad came over to test whether it had anything to do with the Karlock security system. He disconnected it and car is completely silent and cannot start (means the killswitch is working).

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So, the whole time this is happening the only problem with the car is the start-up. Once started, the car drives normal - no hiccups, no other symptoms, everything in the car works normally (it's as if nothing is wrong with it). In the history of my car, I have never had any start-up problems regardless of climate fluctuations; this only started once I replaced the battery. All the connections for the new battery is correct (positive to positive, negative to negative) and so is the starter. For 5 years of its life, it was parked outside on the street and only recently has been able to enjoy a garage. There are no additional modifications made to the car. All oil changes are done as recommended every 5k miles.

Does anyone have any advice or suggestions as to what may be wrong? Any help would be appreciated, please help me

 

As mentioned, it could be a dirty MAF. It could also be a dirty throttle body or fuel injectors.

 

Your alternator might be going bad. If the car started fine when the battery was first put in (charged) and not after, the alternator might only be supplying enough power to charge the battery a little. Charge up the battery either at Autozone or at home if you happen to have a trickle charger and see if the car has trouble starting.

 

^^^ i agree!

edit: i see you didn't do the $110 charge. what a rip.

what you need is a load test on the battery and charging system (this includes the alternator) yeah you want that done. also check the drive belt/fan belt see if it's worn or slipping, might be causing the alternator not to charge the battery up. My dealer has checked out my battery/load test for free as a courtesy, guess each dealer is different. but a load test shouldn't be more than $30 at the most!

The autozone batteries are charged up at the store, they're usually trickle charged if they sit on the shelf for more than a month. it's possible to get a bad battery even with the new autozone batteries made by johnson controls (which makes toyota's battery available at the dealer). so get a load test first. then clean the maf sensor and check the throttle plate for gum/gunk.