Gladstoneiroc

iTrader: (1)

Alright, done a fair amount of searching I just wanted to double check. Motor is stock 305 with open element and headers. The problem is hard backfire though the exhaust. The symptoms occur with warm engine between 1600-3000 rpm with moderate load. First will hiccup with hesitation and then will backfire though exhaust, if I clutch it in time I am able to stop the backfire, but unable to make it much further up a hill.
It has new cap, rotor, plugs, and wires. I took ignition module to advance it tested bad; however, new module also tested bad. Timing is set at 0º but will need reverified.
I am thinking timing chain, distributor, ignition module, or fuel supply. After I recheck timing where should I go?

Gladstoneiroc

iTrader: (1)

Alright replace fuel filter. Tried to measure timing but our gun at work is broken (again). The backfire is getting stronger and harder, like shotgun. However, car still idles wonderfully.

What's the best way to diagonise distrutor from timing chain?

Could a bad ignition module do this?

Or is it the fuel pump?

Gladstoneiroc

iTrader: (1)

Alright ignition module tested good at two seperate places. Timing is set a 0º and roughly 20º with computer advance.

I did fill the tank with hyvee (grocery store cheap) ethanol (E10) gas the day before this happened. I switched the ecms from modified to stock.

Could this be bad gas?

We don't have the right fittings to test the fuel pressure at work so that'll have to wait.

Going to drive around and look for extreme knock or else on the datalogs.

Gladstoneiroc

iTrader: (1)

Alright code 42 and knock occuring at backfiring. I'm getting closer, so I don't have to drive my 7mpg truck.

Edit: I realize code 42 probably comes from unhooking the est wire for checking the timing. Could still be bad esc module? Bad fuel pump? Wiring? 6 month old coil failure? Or distrubutor?

Gladstoneiroc

iTrader: (1)

Well code 42 didn't come back; however, code 25 did show up. I switched coils and have not got another backfire; however, I played it very carefully and did not go on the highway. My .5 mile laps around the shop were cut short by a slipping clutch disc, although the engine was fully hot.

Can't be relay cause I bad relay would still run the pump due to the oil pressure switch, correct?
Is the pump supposed to run a few seconds after the car is shut off?
Could be the ignition coil?
Could be the pickup coil?
Could be bad gas?
Could be fuel pump?

did i get blacklisted on here?

Gladstoneiroc

iTrader: (1)

Changed ignition coil, added 92 octane fuel, and fuel injection cleaner and have not had a backfire in 25 miles. However, I am still leary and the clutch is slipping more. But so far so good.