92 LT-1 Hesitation

[GuzTel]

I have a bad hesitation/stumble after the engine is warm. Runs ok when cold. 37,000 miles six speed. Distributer and map sensor replaced last year. No codes show up. Has anyone run into this before?

 

[invinceablevett]

I have a bad hesitation/stumble after the engine is warm. Runs ok when cold. 37,000 miles six speed. Distributer and map sensor replaced last year. No codes show up. Has anyone run into this before?

..................I had the same problem a few years ago.My 92 convertible automatic would hesitate at wide open throttle,right before it would change gear.The dealers took it in a couple of times but never found the problem.A speed shop took it to a test on "rollers" and found out that my vette didn't respond well enough to the stock"long lasting" spark plugs.We decided to put regular GM spark plugs.I haven't had a problem yet.......just for your info... ..........My dealer told me that they had changed all the plugs......I really don't believe they did......hope this helps.

 

[GuzTel]

What are you using to down-load codes?

Shorting the pins and reading the check engine light.

 

[GuzTel]

..................I had the same problem a few years ago.My 92 convertible automatic would hesitate at wide open throttle,right before it would change gear.The dealers took it in a couple of times but never found the problem.A speed shop took it to a test on "rollers" and found out that my vette didn't respond well enough to the stock"long lasting" spark plugs.We decided to put regular GM spark plugs.I haven't had a problem yet.......just for your info... ..........My dealer told me that they had changed all the plugs......I really don't believe they did......hope this helps.

This is not at wide open, if you push on the gas easy it is fine but any quick movement it hesitates like when the excelerator pump was bad on carbs in the old days.

 

[atmmac]

i hate those accelerator pumps mine went bad so many times on my impala. Change the plugs and check the air filter. See if that works.

Good Luck,
-Andy

 

[GuzTel]

Thanks, I am going to try that anyway should have done it when I changed the water pump and distributer. I did also check the fuel pressure and it was right on.

 

[regalniz]

my k and n air filter oil clogged up my mass airflow sensor and caused warm hesitation. replaced with stock gm filter and problems went away.

 

[GuzTel]

I'll check that I have a K & N too. Thanks

 

[garycr14]

Often times when cleaning and reoiling a K&N filter, people tend to over oil them which can block the airflow. I would suggest recleaning the K&N, then carefuly reoiling, then reinstall. See if that helps. K&N has the best filter on the market when used correctly.

 

[GuzTel]

I'll be cleaning and checking this weekend and post an update. I may have been a little heavy with the oil. If so an easy fix too. Thanks for the input.

 

[regalniz]

i never got a chance to re-oil the filter because my hesitation problem started about a month after i bought the filter. ac delco filters have worked fine for many years. if you want to open up some breathing cut open your air filter housing lid or buy one from one of the many corvette suppliers.

 

[GuzTel]

Here is an update, cleaned and reoiled the K&N but put in a stock for now just to see. Also removed and cleaned the throtle body because it was dirty. But no improvement, there is also a misfire under load beside the hesitation off of idle. Hmmm going to go after those wires and plugs I should have changed with the distributer.

 

[GuzTel]

Here is an update, cleaned and reoiled the K&N but put in a stock for now just to see. Also removed and cleaned the throtle body because it was dirty. But no improvement, there is also a misfire under load beside the hesitation off of idle. Hmmm going to go after those wires and plugs I should have changed with the distributer.

Finally got aroung to going after th e plugs and wires, guess what I found? The water pump I put on last year was leaking and going right into the distributer. Anybody have any luck having GM replace bad parts???

 

[redc4corvette]

The GM dlr will claim it is damage after the fact and you will be stuck.
my total bill would have been 1800.00 but when they replaced my water pump last mth I had the opti-spark replaced also, I got the dist from pace performance in ohio $350.00 only a couple of hundred more because the water pump was already off .
they wanted 1200.for the distributor and i laughed and said put this in so they did ,also replace the sensor in the water pump and the bushing in the timing cover or you will be back at the dlr next week .
AT Mr good wrench the" moto is "we don't have time to fix it right the first time so that is why they call it a come back they always have time to fix it right the second time.