tankman

Good morning everyone,

At your convenience,would you offer me some advice that might solve my '87's issue? My car runs great during cool weather,it has done this the entire 4 years that I've owned it. During hot weather the car is slow and unresponsive. I am an old fart and do not race,but I do like to "keep up with traffic" .
I have completed several basic tune ups (plugs,cap,wires, filter changes, etc),the 'vette always starts up and idles very well. I really enjoy driving it,but when outside temperatures are above 80 degrees,it acts like it does not want to live up to its name.
Now that the temps have fallen,the 'vette is much quicker on takeoff,does not overheat quickly,and acts like it's trying to get me some tickets.
Thanks in advance for all positive responses.

tankman

pmihaltian

Have you cleaned out the front of your radiator and A/C condenser? When I cleaned mine out and replaced my condenser, my engine temeratures dropped by about 15 degrees. Now the engine runs much cooler under ALL conditions.

Check it out....

leesvet

Yep..

pulling the top radiator shroud off for a good trash collection would be the 1st place to start. After that, if its the engine operating temps that make it sluggish, it may be time to do cooling system service or just buy a better radiator. Cooler weather helps 'em all. If the car is borderline the ambient temps have a dramatic effect on the performance. You may need injectors...if yours are clogged and sticky they are not spraying well. Thats the same as running lean and that means sluggish performance. Cool temps are extra oxygen. Hot air is less o2 added to less fuel= less performance. Flat, sluggish performance.

tankman

Thanks pmihaltian & leesvet,

Yes,I have cleaned out all of the leaves and stuff from the front of the radiator. I have been leaning towards getting a new radiator,and I did purchase new injectors from Jon (over a year ago),but I haven't mustered up the courage to put 'em in because I know I'm gonna screw the job up. I have watched Calderone's video so maybe I need to grow some & get started.
Thanks again for responding.

tankman

JackDidley

I suggest you datalog the car. You may learn what it needs to run good all the time. Sounds like it may run rich or need more advance if its not running well when hot weather is here.

leesvet

Tank,

the worst part of the injector swap is the subsequent backache.

If you can follow directions and have what you need there with you, its not bad at all. A LOT easier than it looks. Biggest thing is tools. Have a good selection and even some other that are easy to find. For the first timer, the worst part is the realization that the factory runner/plenum gaskets are welded to the runners...and scrape off in tiny little flakes that must be contained. Beyond that aggrevation its cut n dried. Take stuff apart, clean and reassemble. Beside curing a world of running & performance issues the satisfaction factor is tremendous.

tankman

Thanks JackDidley and leesvet,

Thanks for the heads up on the backache. I do have most of the tools 'cause I started getting them together when I purchased the injectors.
I don't think I'm ready for the datalog yet.Hopefully I'll get started on the injector replacement soon.Thanks again

tankman

pmihaltian

Tank:

You NEED to clean the debris out from between the radiator and the A/C condenser. This is where it accumulates and limits your cooling. You can't just clean out the front.

Also, the radiator in your C4 is a pretty high performance NASCAR designed radiator. Before you charge off and spend a lot of money on a new radiator, you should make sure that you have checked for and eliminated ALL the possible cooling system gremllns first.

P.

leesvet

I just noticed his comment..."in front of the radiator".

Tankman,
Thats not sufficient. You have to take the top shroud off to access the area between the condensor and the radiator. Looking in the front of the nose, you are seeing the condensor, not the radiator. You cannot see or reach the area in question thru the nose...the only access is from above.

tankman

leesvet,
Thanks. I understand & will get on it this weekend.

leesvet

The 87 is not bad...use a cordless driver wih socket adaptor and its cake...

there are about 8 or 10 10m bolts around the shroud flange then the fron edge has 5 or 6 smaller...4mm maybe bolts. You have to pull the top hose off, and maybe the trans cooling lines..I forget, The trick is to cut slots in the shroud so you can remove and install next time without having to disconnect anything.
Take the air cleaner off, maf and set aside then go to the bolts and hose.

Once you can lift the shroud up and off, ou will see the 2" space between the cndensor and radiator thats likey got an assortment of trash in there...I have personally found road kil, tons of feathers, hair (???) and every form of roadside trash thats seen along the hiway...Plastic bags are the death blow to these cars...

There was a story many yrs ago about a kid that picked up his dads vette aftr the engine was rebuilt. Driving home he sucked up a grocery bag...the plastic that we use in trash cans, and it got between nd blocked most of the air. Not paying attention he drove it some distance and fried the new engine.....

Don't know if thats BS tales or not, but it drives the point home. If your temps are unusually high,thats the place to look.
Norm is between 195 to 225 depending on traffic or cruising and ambient temps.

tankman

Thanks again leesvet.

eatmydst1234

Maybe I read the original post wrong, but besides the heating up not as quickly when it's cooler out it also stands to reason the car would run stronger too, cooler air is more dense. The engine in your car makes more power with cooler air than hot air..

tankman

Thank you.