C4 Suke

My car would take forever to start and would run rich. After changing the fuel pump and almost changing the fuel injectors, I decided to just change the fuel pressure regulator since its pretty cheap compared the everything else. It's also really simple to do.

That solved the hard starting and running rich problem, but I still have a rattling noise when I accelerate. What can be causing this? How can I get rid of it? Thanks, Suke.

nobodyunknown

Probably low octane gas. If not, mabey you have your timing advanced to far.

C4 Suke

I'm using 93 octane, the highest at Mobil, I think its timing but was wondering what other causes there might be.

Corvette ED

Your EGR Valve is bad.

snydcat

My 85 is also pinging pretty bad when I accelerate. It just started about a week ago and it is driving me crazy! I have changed the plugs, checked the timing(fine), did the GM upper engine cleaning thing, run 93 octane gas(also added octane boost). It's not running hot(highest temp. all summer is 225)other than the pinging the car runs good. The only thing else I can think of is the EGR Valve like Corvette Ed said. Looks like I will be changing that out this weekend.

Rich

C4 Suke

Thanks for the replies, I'll check out the EGR valve.