lt1 hesitation??

[Oldskool153]

anyone ever had this prob 99% of the time my 92 lt1 runs perfectly in the city and on the highway..but id say one out of every 100times that i mash on the gas while on the highway I will get a hesitation almost like the car is low on fuel and it isnt getting fuel than after a second it will pick up and take off..any ideas as to why this happens so rarely? i just put sea foam in it an im hoping its maybe just a piece of dirt in one of the injectors that will clear out. Should i be concerned, car is going to my mechanic this week for an unrelated issue, i would tell his to look into this but it happens so rarely (knock on wood) that i doubt he would be able to reproduce the prob.

 

[LT4man]

How many miles are on your Vette?

Do you have an automatic or manual transmission?

 

[surfer93]

You are probably at a low rpm and the car is not downshifting correctly.
If it is a auto and it happens at 40-55, pretty sure you need to adjust the TV cable.

 

[Oldskool153]

auto just turned 84k, i dont think its the tv cable, the cars shift points are right on and car downshifts flawlessly..im thinking its a fuel issue but again it only happens maybe one out of every 100 times if that, ive put 2k on the car since i bought it in sept and its done it maybe 2 times..(again knock on wood) but its still alittle concerning to me as to why it would do it at all ever? could it b the fuel filter?

 

[Hib Halverson]

"Seafoam" will not clear solid material out of injectors, if that's what you have. Particles, too large to go through the injector discharge holes is going to stay there for good.

The reason there is a fuel filter and a screen at the top of the injector is to prevent sold matter from entering the injector, however, that won't stop rust particles which can develope inside the inector.

That said, since the engine otherwise runs ok, I'm thinking it's not injectors.

Have you run the fuel pressure tests listed in the Factory Service Manual. If so, what were the results.

If the fuel filter has not been changed in the last 30,000 miles, change it now.

 

[Oldskool153]

I have not done fuel pressure test as i do not know how, and I also have no info about the history of the car before i bought her.im attempting to contact the previous owner asap

 

[9340Ruby]

I have not done fuel pressure test as i do not know how, and I also have no info about the history of the car before i bought her.im attempting to contact the previous owner asap

I had this same intermittent symptom before I replaced the fuel pump in my '93. It has not done it since(approximately 1 1/2 years ago). Amazing difference in the way it starts and runs now. When I replaced my fuel pump the original pump wire sheathing was fraying away in the tank(not good). I am glad I replaced it. I bought the Lingenfelter pump and it was plug and play. Good luck. BK

 

[Oldskool153]

I had this same intermittent symptom before I replaced the fuel pump in my '93. It has not done it since(approximately 1 1/2 years ago). Amazing difference in the way it starts and runs now. When I replaced my fuel pump the original pump wire sheathing was fraying away in the tank(not good). I am glad I replaced it. I bought the Lingenfelter pump and it was plug and play. Good luck. BK

is my pump in my gas tank? how hard is it to change for a backyard mechanic with no lift working from the ground? and how much is the pump?

 

[9340Ruby]

is my pump in my gas tank? how hard is it to change for a backyard mechanic with no lift working from the ground? and how much is the pump?

Yes, it is in the gas tank at the filler neck. Search on this site for great instructions. I don't have the link. I did it standing up with the car on the ground. Rough description: pull out rubber filler guard, unscrew bots and pull out the pump. Here is the link: Lingenfelter Performance Engineering: Fuel Pumps & Filters

It comes with a new rubber seal and new bolts to put the pump back in. I was impressed with the plug and play of the unit. Very simple to change. If I find the link I will post it for you. Do a search online as well. That's what I did. Hope this helps. BK

 

[Oldskool153]

thanks, i guess even if thats not the problem it cant hurt to change it after 84k

 

[9340Ruby]

thanks, i guess even if thats not the problem it cant hurt to change it after 84k

I agree. I did mine at 55,000 and it made a world of difference. I hope the same for you. BK

 

[TWISTERUP]

is my pump in my gas tank? how hard is it to change for a backyard mechanic with no lift working from the ground? and how much is the pump?

IF.. you've determined the fuel pump is bad....it is in the tank..access the sender/pump beneath gas door from the top...you won't need to be under the car at all.

 

[surfer93]

thanks, i guess even if thats not the problem it cant hurt to change it after 84k

Instead of throwing money at the problem, diagnose.

Have you OHM'd the injectors to see if you have a bad one?

Get a fuel pressure gauge and hook it up to the right side schrader valve and turn the key on, but do not start and check the pressure.
Should drop slowly, if it drops fast you have a pressure problem.

Have you checked the air filter, a clogged one will cause this problem.
You never stated what rpm and speed this problem occurs, there is tons of different things that could cause this.

 

[93Rubie]

Have you checked the air filter, a clogged one will cause this problem.
You never stated what rpm and speed this problem occurs, there is tons of different things that could cause this.[/QUOTE/]

Heck, hesitation on tip in, could be a Throttle Postion Sensor...if you got a problem with that, it would be like missing an accelerator pump on a carburetor.

 

[Retired11B]

I had a similar problem with my 93 40th Aniv. Vette. Turned out that two of my spark plug wires had gone bad. That might be worth checking out, too.

Mike