ronniev

So I just got my baby home after deciding on this low mileage mint condition car and...I wanted to take her for a drive to make sure everything was good to go since it'll be stored for a good 3 months. I warmed it up for 10 minutes at idol. Took it for about a 5 mile drive when about 3 miles in, I kicked down the gas, and there seemed like when it down shifted, it started shaking, sputtering and little to no power. I chugged it home with about ¼ throttle. that worked to get it home. But when I apply more than ¼ throttle-no power, chugging, and such. It’s a 94 LT1 with auto and 27500 miles. This feels very similar to when I owned a 04 Lincoln LS with the 3.9 v8 and I had 2 coils go out. YES I SEARCHED-Blown gasket-optispark-tune up-bad/dirty fuel injectors- bad fuel pump- bad fuel filter-dirty maf sensor- bad o2 sensor, clogged cats and so on. blah blah blah. Just was curious if anyone had exactly this happen and maybe could enlighten me to what I'm in store for when I find a reputable Corvette shop in Minnesota. Gosh-I feel sick about it! I'm trying to get ahold of the former owner to see if any new work has been done, at least in the last year. Would you start with a tune up and go from there? Hoping for the best!

bow tie guy

could be as simple as a corroded injector plug, or clogged "low mile" injecrors! try some techron and fresh fuel! a cap, rotor, plugs and plug wires wouldn't hurt

Bottom line self diagnosis (aka parts changing) gets expensive have a pro look at it and pay for a diagnosis the right way

That's a pretty nice Car you got there don't feel bad about putting some money into it

check your fuel pressure

92ragtop

I had symptoms just like that, and it was my pump. Easy fix if that's the problem.

antfarmer2

best to post and listen unless you want to pay more than you paid for the car a lot of good info here for free. if your not able or willing to work on your own car best get rid of it or be ready to pay dearly.

mwm1993

Check for any codes and check fuel pressure. I would not be surprised if it was bad fuel. I worked on an 86 grand national a few months ago that had sat for a long time. This thing had 6,250 original miles!! I got it running but it wouldn't idle. Drained the old gas out and filled with new and the car ran perfect. I was impressed how quickly it built boost too.

Keep us in the loop there are a lot of knowledgeable people here and don't be afraid of the car

skullandbones

It does sound very much like a fuel pump. I hear these are a common problem. They can have symptoms that very widely depending on the intermittent nature of the problem. They won't always accommodate you by just dying all at once. About the only way to diagnose is to check fuel pressure not only statically but under load if it is failing slowly. On a particularly sneaky fuel pump fail on my Nissan truck, I finally, went thru a series of cycles and listened very carefully. It didn't sound quite right. It turned out to be the pump. It was running but didn't bring the fuel rails up to pressure. A reputable shop should be able to put it on the diagnostic equipment and give you a flat rate for that and estimate for repair when they find it. I took my Toyota to a good Toyota service/dealer. They did a complete assessment of the problems including a CEL and handed me a printed booklet with every system check and what I needed to do to fix it (brakes, tires, coolant, trans, transfer case, injectors, belts, etc). Now that's worth the $100 bucks to give you a good reference point with your new ride. With my Toyota, I had gotten to the point I was ready to sell it with all the little problems. I used the booklet to get it back up to standard over time and still drive it to this day.

Good luck with the fix,

WEK.

auggy

The car wasn't driven enough and you are adding to the prob by putting it away. Smell the gas, if it smells like turpentine suck out the fuel and don't drive the car. Put in a top tier hi octane fuel like shell or exxon--shell being the best-----put in 3 gallons add startron starbite 1or 2oz which will help get rid of any water. drive the car and good luck.

ronniev

Thank you so much everyone. I know it's not the gas-it's fresh NON OXY that was just put in. I am going to call BOOSPERFORMANCE here in MN. Supposedly, he is a legend! I tremendously appreciate the feedback-especially the comment about not being able to work on her myself, which I cannot, and spending a fortune. That sure makes a guy think!

ronniev

Not the gas-I drove it 200 miles back to MN with no problems and then put another full tank of NON OXY 01octane fresh gas, that's when this started happening. Thanks

corvetteronw

You live in Minnesota? Ex Michigan owner here.
Do a Google search for "LT1 throttle body bypass" and look at your car to see if this modification has been done. Even though you said you warmed the car up for a bit you might be experiencing throttle body icing.
GM designed your car to have hot water flowing through the throttle body to prevent the cold weather icing. Many owners bypass it but experience no problems as they either do not drive in cold weather or they live in a warmer climate. The modification allows cooler and thus denser air to enter the intake system.

Bluezman

...Replace the fuel filter. There's also a sock filter on the fuel pump pick-up tube. They can get clogged. Just a thought.

I replaced my fuel filter because my car would idle but would die if you tried to move it. I couldn't blow air through the old filter. I replaced it and the problem was immediately GONE!

bow tie guy

Coolant temp sensor could cause it to run rich, and foul plugs
the car is now in an extremely cold climate (from florida?)
any check engine lights

ronniev

No codes or CEL's... It's from IOWA originally

illenema

Will it run better on a ice cold engine before it goes into closed loop?

PAPERBKWRITER

I feel your pain. I just bought a '94 coupe (45k cherry) and tried to contact the former owner. I set my phone #, email and a SASE and got not reply. Like you I'm parking the car until the spring (other than the test drive I only did 6 miles) but I would have liked to find out what he did. The dealer told me the car ran rough when they got it but they put in a new fuel pump and it is very responsive now. I hope you find the problem.

ronniev

Thanks PAPERBKWRITER. I will be getting a diagnostic from one of my local CHEVY dealers from their Corvette "SPECIALIST". We will go from there. I am tempted just to buy NGK Iridium plugs, Taylor Plug 8MM plug wires, fuel filter and start with that. I think at the very least, it will need those items anyways. Then after those are installed, can possibly narrow it to OPTI,Fuel Pump,.....garage queens are not what they seem, but it was my choice to go with the lowest mileage car and I will live with it and own it!

skullandbones

Hi ronniev,

I like your plan. You aren't wasting any money by changing what you listed and it will simplify the laundry list of possibilities for your technician.

Good luck. Hope it turns out OK.

WEK.

ronniev

Not sure...-Diagnostic scheduled for Monday the 28th

SJW

This sounds very much like a fuel starvation problem. If so, it shouldn't be too costly to fix.

Live well,

SJW

antfarmer2

put a fuel pressure gauge on it might just need a filter or a sock.