swt1313

I have an '83 Z-28 with a 305 and crossfire fuel injection. When the engine is cold, it starts perfectly. When the engine is run for any length of time, shut off, and immediately retarted, it starts perfectly. When the engine is run long enough to reach max operating temp(200-220 degrees F), shut off, and left off long enough to cool to between 125-175 degrees F, it does not want to restart. It initially starts for 2-3 seconds, begins to lope(like an engine with an oversized cam), sputters, and dies out. The only way to start the engine in this situation is to pump the throttle wide open, until it evens out and clears up(may take up to a min). Propping the hood open after parking the car solves the problem, and mixing race fuel with 93 octane helps, but does not fix the problem. I obviously have a gas/heat problem, but the mechanics I've dealt with are stumped on the exact cause of the problem. I have replaced spark plugs, plug wires, rotor cap, ECM, engine temp sensor, fuel filter, checked fuel pump(good), fuel pressure(11lbs), and made sure the injectors are not leaking gas into the intake after parking the car. My problem started in the summer of '09, about the time ethanol was introduced in our gasoline. Does anyone think my problem is related to 10% ethanol in the gas? Has anyone had a similar problem, or know what my problem is?

82_Camaro

i have the same problem with my 82 cfi. i intend to go through the engine this winter. i suggest doing the same thing. if you find another way to fix the problem please send me a message.

sofakingdom

iTrader: (1)

Sounds like leaky injectors; fuel is dripping into the intake while the engine is off, which is what causes the "flooding" symptoms. In fact that's almost the only explanation which accounts for the symptoms at hand. See my signature for the words of a very wise man, that can help keep your brain pointed in the right direction at all times.

No I don't think the ethanol is related at all, unless it happened to dislodge some schmutz in the system somewhere which then got lodged somewhere that it now prevents an injector from sealing off properly.

"Going through the engine" is probably not going to do a whole lot of good, under those circumstances; if the problem is not in "the engine", but rather is in the injectors, it will remain unchanged.

CFI is basically the same as any other TBI, as far as how it works. YOu might be able to get more help on the TBI board.

Meanwhile, I'd suggest just popping the injectors off of the TB, and soaking them for a day or 2 in lacquer thinner.

five7kid

iTrader: (14)

Heat soaking is harder on electrical parts than anything else. The three most common culprits are the coil, the ignition control module, and the distributor pick-up assembly. For some reason, they seem to mimic fuel problems...

If opening the hood helps, I'd lean toward an electrical rather than a fuel problem.

sofakingdom

iTrader: (1)

Sure does sound fuel-ish.... can't think of a single electrical thing that can account for that behavior.

82_Camaro

I changed the injectors already yet I still have the same problem

sofakingdom

iTrader: (1)

Other possibility is the fuel pressure regulator(s)... that has fuel pressure on one side of the rubber diaphragm, intake on the other... when the rubber ruptures the same thing happens

swt1313

82_ Camaro: Does the gasoline in your state have ethanol in it? If so, did the problem start when ethanol was first introduced? I'm still thinking heat in the engine compartment is doing somthing to the ethanol in the fuel lines.