trouble shooting gurus please help.
Thread Starter
Racer
Joined: May 2014
Posts: 492
Likes: 67
trouble shooting gurus please help.
Hey guys I'll try to be descriptive with out making it to long, any input would be great.
picked up this vette Friday and have one issue. it is taking quite a bit of cranking to start and when it does it has a bog down/hesitation when initially giving it gas. or coming to a stop at a stop light. once i get going if i mash it it responds just fine but when stopping and taking off i have to feather the gas. closest i can relate it to is a flooded carb.
the dealership i got it from said it recently had a tune up including a "distributor" hmm but if it was the opti spark i don't think it would be only at idle??? please help.
thanks
brian
picked up this vette Friday and have one issue. it is taking quite a bit of cranking to start and when it does it has a bog down/hesitation when initially giving it gas. or coming to a stop at a stop light. once i get going if i mash it it responds just fine but when stopping and taking off i have to feather the gas. closest i can relate it to is a flooded carb.
the dealership i got it from said it recently had a tune up including a "distributor" hmm but if it was the opti spark i don't think it would be only at idle??? please help.
thanks
brian
Thread Starter
Racer
Joined: May 2014
Posts: 492
Likes: 67
Sorry guys, 1994 - lt1 with auto.
What injectors would i replace with? I found plenty on ebay but they mention ev1???? Sorry guys i only know carb motors... This is new territory for me. I seen one listing saying 30lbs injector upgrades... Would that be ok. I do plan on rebuilding this winter with better cam, headers and performance heads.
What injectors would i replace with? I found plenty on ebay but they mention ev1???? Sorry guys i only know carb motors... This is new territory for me. I seen one listing saying 30lbs injector upgrades... Would that be ok. I do plan on rebuilding this winter with better cam, headers and performance heads.
Pro
Joined: May 2002
Posts: 635
Likes: 6
From: New Jersey
Sorry guys, 1994 - lt1 with auto.
What injectors would i replace with? I found plenty on ebay but they mention ev1???? Sorry guys i only know carb motors... This is new territory for me. I seen one listing saying 30lbs injector upgrades... Would that be ok. I do plan on rebuilding this winter with better cam, headers and performance heads.
What injectors would i replace with? I found plenty on ebay but they mention ev1???? Sorry guys i only know carb motors... This is new territory for me. I seen one listing saying 30lbs injector upgrades... Would that be ok. I do plan on rebuilding this winter with better cam, headers and performance heads.
Randy
Safety Car
Joined: Aug 2009
Posts: 3,751
Likes: 275
From: Melbourne, Victoria, Australia
Hi
The hard starting could be caused by a number of things, the first thing to do is set the base idle. If someone has adjusted the throttlebody screw that can cause some problems, the IAC valve has some room to adjust either way so it would need to be a big change.
I do not know much about the 94 so hopefully someone will post the procedures, yes fuel injectors can leak or the fuel pressure regulator diaphragm tear but that would put fuel through the vacuum hoses and can flood the sump with fuel.
Best thing to do is get a shop manual for the 94 vette, that has all the diagnostic info to help trace down and fix any issues.
For fuel injectors call John from FIC
http://www.fuelinjectorconnection.com/
The hard starting could be caused by a number of things, the first thing to do is set the base idle. If someone has adjusted the throttlebody screw that can cause some problems, the IAC valve has some room to adjust either way so it would need to be a big change.
I do not know much about the 94 so hopefully someone will post the procedures, yes fuel injectors can leak or the fuel pressure regulator diaphragm tear but that would put fuel through the vacuum hoses and can flood the sump with fuel.
Best thing to do is get a shop manual for the 94 vette, that has all the diagnostic info to help trace down and fix any issues.
For fuel injectors call John from FIC
http://www.fuelinjectorconnection.com/
Thread Starter
Racer
Joined: May 2014
Posts: 492
Likes: 67
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Race Director
Joined: Sep 2003
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From: Database Error Indiana
Le Mans Master
Joined: Dec 2006
Posts: 5,139
Likes: 482
From: H-Town Texas
To be honest, your first major purchase for this car should be the Factory (Field) Service Manual, aka FSM.
I will say one of the things that seems to always get overlooked is the fuel pressure regulator. It is located at the rear of the fuel rail on the driver's side. There is a vacuum hose attached to it. Pull that hose and see if there is any fuel comeing out. I had very similar symptoms, and this was the issue.
Race Director
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
Thread Starter
Racer
Joined: May 2014
Posts: 492
Likes: 67
Couldn't agree with this more.
To be honest, your first major purchase for this car should be the Factory (Field) Service Manual, aka FSM.
I will say one of the things that seems to always get overlooked is the fuel pressure regulator. It is located at the rear of the fuel rail on the driver's side. There is a vacuum hose attached to it. Pull that hose and see if there is any fuel comeing out. I had very similar symptoms, and this was the issue.
To be honest, your first major purchase for this car should be the Factory (Field) Service Manual, aka FSM.
I will say one of the things that seems to always get overlooked is the fuel pressure regulator. It is located at the rear of the fuel rail on the driver's side. There is a vacuum hose attached to it. Pull that hose and see if there is any fuel comeing out. I had very similar symptoms, and this was the issue.
The dealership is three hours away. My warrenty only cover block, heads, valve train, trans and rear end and i have to pay all diagnostic fees. It doesnt seem like it would be any of those.
Typing this on my phone from work so sorry if grammer is poor.
Thanks guys, your input is greatly appreciated. I will dig i to it over the weekend.
Le Mans Master
Joined: Dec 2006
Posts: 5,139
Likes: 482
From: H-Town Texas
Should there be feul coming out?
The dealership is three hours away. My warrenty only cover block, heads, valve train, trans and rear end and i have to pay all diagnostic fees. It doesnt seem like it would be any of those.
Typing this on my phone from work so sorry if grammer is poor.
Thanks guys, your input is greatly appreciated. I will dig i to it over the weekend.
The dealership is three hours away. My warrenty only cover block, heads, valve train, trans and rear end and i have to pay all diagnostic fees. It doesnt seem like it would be any of those.
Typing this on my phone from work so sorry if grammer is poor.
Thanks guys, your input is greatly appreciated. I will dig i to it over the weekend.
Post up what you find when you get to it.
Thread Starter
Racer
Joined: May 2014
Posts: 492
Likes: 67
ordered an iac, will be here in a couple days. stopped by advanced auto and grabbed a fuel regulator. put it on and it worked. so a big thank you guys. when i pulled the vacuum line off gas did come out. so swapped it out and runs a lot better. still has a very slight hesitation on initial throttle but I'm thinking with the new iac and tune up hopefully that will go away as well. i do plan on tearing this motor apart this winter so this will get me through the summer.
thank you, thank you, thank you.
Brian
thank you, thank you, thank you.
Brian
Instructor
Joined: Jan 2014
Posts: 213
Likes: 4
From: San Francisco California
Ugh...I posted a nice writeup and then deleted it when I saw you wrote that a fuel regulator worked.
Afterwards, I saw that you still have a slight hesitation.
Check your spark plug wires...I had the same bog/float/hesitation symptoms with mine and it turned out that the previous owner never replaced the spark plug wires because it was much harder to do so with the optispark. A lot of home mechanics do spark plugs, but not plug wires as they get intimidated when they see the waterpump and optispark.
Could be they are still original or old like mine were on my '95 LT-1.
That solved my problem and similar symptoms instantly.
Roy
Afterwards, I saw that you still have a slight hesitation.
Check your spark plug wires...I had the same bog/float/hesitation symptoms with mine and it turned out that the previous owner never replaced the spark plug wires because it was much harder to do so with the optispark. A lot of home mechanics do spark plugs, but not plug wires as they get intimidated when they see the waterpump and optispark.
Could be they are still original or old like mine were on my '95 LT-1.
That solved my problem and similar symptoms instantly.
Roy
Le Mans Master
Joined: Dec 2006
Posts: 5,139
Likes: 482
From: H-Town Texas
ordered an iac, will be here in a couple days. stopped by advanced auto and grabbed a fuel regulator. put it on and it worked. so a big thank you guys. when i pulled the vacuum line off gas did come out. so swapped it out and runs a lot better. still has a very slight hesitation on initial throttle but I'm thinking with the new iac and tune up hopefully that will go away as well. i do plan on tearing this motor apart this winter so this will get me through the summer.
thank you, thank you, thank you.
Brian
thank you, thank you, thank you.
Brian
I agree with Landshark about the wires. And check the plugs, if you got it from a dealer, you don't really know if what they call a 'tune up' is what you would call a 'tune up'.
Also try driving a bit with some fresh premium 91 or 93 if you can get it. Again, if was sitting on a dealers lot and not driven alot, or if they put the cheap gas in it, a tank or two of the good stuff might help.
Clean up the MAF, and check your pcv valve, and look for vacuum leaks.
Thread Starter
Racer
Joined: May 2014
Posts: 492
Likes: 67
well drove it today to work and it drove awesome. then on a short road trip .. it started up again 
this makes no sense. it ran great then started bogging out again. i pulled the vacuum hose off the new regulator and no fuel came out. i still haven't put the iac on yet sense it hasn't arrived yet. any thoughts? the spark plug wires are new.... feels like something with the fuel. ran awesome for then back to bog grrrr
this makes no sense. it ran great then started bogging out again. i pulled the vacuum hose off the new regulator and no fuel came out. i still haven't put the iac on yet sense it hasn't arrived yet. any thoughts? the spark plug wires are new.... feels like something with the fuel. ran awesome for then back to bog grrrr