Bredd1

Today after driving my car I kinda got the smell of raw / unburned gas. I've been tinkering with this car over the past 8 months trying to get it running well enough to drive. I've been having some problems with engine wanting to hunt between 600 to 800 rpm. I made some adjustments to the idle speed to compensate for the constant change and also set the TPS. Any ideas about the gas smell or hunting. I've checked and replaced several bad vacuum hoses. Now the car seems harder to start than before & idles very low at start up. New suggestions?

Bredd1

No more ideas?

WW7

Sounds like you should put it on a scanner to see if all the perameters are correct, and all the sensors are working properly. If you think one of your cylinders isn't firing, put a timing light on each of your plug wires and see if they all light it up, if one doesn't light it up, you have a cylinder thats out..There are alot of things on these engines that can only be checked with a scanner...WW

red89c4

plug wires leaking?
compression, fire, fuel, you must have all three, check each one, one at a time and start eliminating them from the possible problem list

red89c4

just saw this, after reading your post????

http://forums.corvetteforum.com/c4-t...-manifold.html

Bredd1

Thanks for these suggestions, I will try some of these this weekend.

Bredd1

OK, I checked that each cylinder is firing using a timing light and they were all firing. I was able to determine that the engine hunting is occurring when the A/C compressor is running and gets worse when the cooling fan comes on, it wants to hunt between 600 & 800 rpm. It idles fine when the A/C is off. Also it seems that the raw/unburned gas smell comes right after the engine is turned off, and it goes away after a short time.

red89c4

if you have fire and compression, then you must have a fuel problem. too many post about fuel regulators to not check in that direction, unfortunately that is my weakest area.

Bredd1

I did replace the fuel filter, is there some way that I can check to see if the fuel regulator is functioning properly?

93Rubie

Pull the vacuum line off the regulator if you see liquid fuel it is bad.
Test fuel pressure at Key On Engine Off, then at idle.
At idle pull the vacuum line off the FPR and the pressure should go up.

Bredd1

OK, I'll try that this weekend.

aminnich

[QUOTE=Bredd1;1579858256]OK, I checked that each cylinder is firing using a timing light and they were all firing. I was able to determine that the engine hunting is occurring when the A/C compressor is running and gets worse when the cooling fan comes on, QUOTE]

How is your alternator output and battery condition??

Bredd1

Both alternator & battery are new. Getting just over 13 volts when idling.