Hard Starting
Thread Starter
Melting Slicks
Joined: Nov 2001
Posts: 2,622
Likes: 0
From: Vancouver BC
Hard Starting
Hi usually when i'm starting my corvette for the first time in the day it starts (goes vroom) but if i don't hold that pedal down to keep the revs up high for a bit the revs fall and i actually hear that engine kinda slow and then stall. then it wants to start really hard but usually turns over. i changed the plugs and wires over and even the fuel filter a little while ago and the car would start on the first turn of the key and i'd hold the key into the start position for like half a second than my usual 2 seconds. but well that was the day the spark plugs were put in and well now its starting hard again. my uncle told me maybe my fuels bad?? i've been filling Supreme in the car its like 92 or 93 octane or something like that? is this the symptom if so how to fix it? just buy and dump one of those fuel cleaners into the tank such as the STP stuff or Valvoline stuff?
thanks
davin
thanks
davin
Drifting
Joined: Nov 1999
Posts: 1,801
Likes: 2
From: St. Paul MN
Re: Hard Starting (dmalhi1)
You will get all kinds of opinions on fuel system cleaners. I personally have had good luck with Valvoline Synchron I think it was called. I think I would first try that. It can't hurt. Then you will want to check the fuel pressure during cranking and after engine shut down. The pressure should stay up after you shut the key off for awhile. If it is dropping there is a way to determine if it is a leaky fuel injector or the check valve in the pump. Good luck and keep us posted.
Team Owner
Joined: Sep 2001
Posts: 62,066
Likes: 1,722
From: Athens AL
C7 of the Year - Unmodified Finalist 2021
C4 of Year Finalist (performance mods) 2019
Re: Hard Starting (dmalhi1)
I would doubt if it was bad gas if youre putting in high octane. The STP fuel injector cleaner is ok, but only at every 3k, no more than that in my opinion. This seems to be a common problem, id run a search on this too, i remember hearing this alot.
Race Director
Joined: Sep 2000
Posts: 12,182
Likes: 1
From: Partying with the Cowboys cheerleaders in Mt. Olive, New Jersey
Re: Hard Starting (dmalhi1)
Hmm, a few things comes to mind...
Check the:
1. MAF sensor connection (check the insides for debris also).
2. Have a tech adjust timing and check fuel pressure.
3. Air filter for excessive dirt.
4. All the thin plastic vacuum hoses in the engine bay. Some could be broken.
All the above have happened to me before. Also, a good once a year maintenance is have a garage do the MotorVac service. This service cleans out all the accumulate grease, scum, sludge out your fuel intake system. Makes the car run like new. Trust me on this one.
Good luck.
Check the:
1. MAF sensor connection (check the insides for debris also).
2. Have a tech adjust timing and check fuel pressure.
3. Air filter for excessive dirt.
4. All the thin plastic vacuum hoses in the engine bay. Some could be broken.
All the above have happened to me before. Also, a good once a year maintenance is have a garage do the MotorVac service. This service cleans out all the accumulate grease, scum, sludge out your fuel intake system. Makes the car run like new. Trust me on this one.
Good luck.
Instructor
Joined: Jul 2001
Posts: 126
Likes: 0
From: Miami, FL, USA
Re: Hard Starting (dmalhi1)
Common problem on the L98's I hear.....I had the same thing. My problem was leaky fuel injectors. I could never find out why the spark plugs kept fouling up after time, but when I put new ones in they were great for a day or so. The problem is that when you shut off the car, the fuel injector(s) leak liquid fuel into the cylinder(s) and that floods them, and fouls up the plug(s) and makes it hard to start.
First of all, start your car, let it run for a minute or whatever, then shut it off. Then start it back up. Shut it off again and then wait a while like a half an hour. If it starts hard the second time and easy the first then the fuel injector(s) leak. Another way to test this is to put a fuel pressure gauge on your fuel rail and watch to see how much the pressure drops. I am not sure how much you are supposed to be looking for...but I think if it drops significantly in 5 minutes or so then theres a leak. I didnt need to do this cuz I knew the injectors were bad. I ended up changing the pressure regulator too. Good luck.
First of all, start your car, let it run for a minute or whatever, then shut it off. Then start it back up. Shut it off again and then wait a while like a half an hour. If it starts hard the second time and easy the first then the fuel injector(s) leak. Another way to test this is to put a fuel pressure gauge on your fuel rail and watch to see how much the pressure drops. I am not sure how much you are supposed to be looking for...but I think if it drops significantly in 5 minutes or so then theres a leak. I didnt need to do this cuz I knew the injectors were bad. I ended up changing the pressure regulator too. Good luck.
