Donovan Ferrel

Just got a '93 camaro z28 with a LT1 engine in it. Will start but have to pump the gas like crazy to keep it going. previous owner said it had a fuel problem. Any ideas where to start?

Injuneer

1: Scan it for codes - easy on a 93, short the pins in the data link connector.

2: Check the fuel pressure - A) turn key to run, the pump will prime for 2 seconds and shut off. What is the pressure when it shuts off? How fast does the pressure drop? B) start engine, take vacuum compensation line off the fuel pressure regulator, plug end of line to prevent vacuum leak. Fuel pressure shoul be 43.5psi (anything in the range of 41-47psi is OK. C) while idling reconnect the vacuum line, pressure should DROP about 8psi. D) If you can keep it running, tape the gauge to the windshield, take it out on the road under max load, WOT at 5,000 RPM. Pressure should not drop below 40psi.

3: If no codes and fuel pressure is OK, download Scan9495 (also works on 93), data log the ECM and one of us will review the data log for you, See "sticky" post on "Computer Diagnostics......" forum.

GaryDoug

Instead of pumping the accelerator, have you tried just holding it to the floor steady until it smooths out?

Donovan Ferrel

Tried that. Doing that wont even start the car.

Injuneer

Pumping the throttle while cranking the engine doesn't do anything except flap the blades. Doesn't result in more fuel. Holding the pedal down puts it in "clear flood" mode, if the engine is flooded with fuel.

Donovan Ferrel

I'm getting a good 40 psi on the fuel but still dies. Haven't checked for codes yet. I really wonder what could be keeping this thing from not wanting to idle?

Injuneer

Pulling the codes takes a paper clip and ten minutes:

Courtesy of Shoebox

http://shbox.com/1/dlc2.jpg

Ananta1369

Need a paper Clip? Sure would like to know what this issue is/was as I have a 93 as well. Since 93's are unique I like to keep up a knowledge base of these things...

Injuneer

Appears "Donovan Ferrel" signed on late on 09-05-2016 and read post #7, and never signed onto the site again. Would be nice if people would follow up with feedback, to build a meaningful "knowledge base", but I guess that's asking a bit too much.