BadBirdie

hopefully this is easily identifyable as there are some unique clues.

1. this problem was happening about a month ago after i drove through rain, but until yesterday the car ran great for about a month like i said, then started doing the same thing yesterday and it did not get wet.

2. my ses light is always on due to the rear o2s not being tuned out, but during this issue the ses light is flashing.

ok so the car starts up just fine everytime, there is no issue there. after about 5 mins of driving the car stumbles bad and struggles to get above 30 mph, feels like a really bad miss. stopped at a light the rpms drop to 400-500 when they are normally 900 on my car. standing next to the car and reving in neutral you can hear it backfire. it has not completely died on me yet so that should also narrow down possibilities.

last night i tried driving home from work and the car started acting up like this so i pulled over about 2 blocks from my work and left the car there overnight. im going back later today to try and drive it the rest of the way home.

from the reading i've done it seems like the culprits are:
opti
coil
icm
fuel pump

HELP!

SilverSS07

iTrader: (1)

See what the other trouble codes are. It's easy to check fuel pressure with a gauge. I would think it's ignition though and the SES is probably flashing because of a misfire. You could check the ohms on the coil and visually look for any burned plug wires or anything.

TimmyZ28

SES flashing is indicating that the car is misfiring. Backfire is usually a timing thing or an ignition misfire. It's possible that optispark just went out on you but make sure to check everything else. Fouled plugs, hold the coil wire near the coil terminal to see it arc indicating spark at that point.

BadBirdie

well i just went and picked up the car and drove it about 7 miles home and didnt see any problems. i shut it off in my driveway so i could move another car out of the garage so i could pull it in and get it up on jack stands. when i restarted it i had the issue again flashing ses light and low idle.

this is exactly what was happening a month ago, sometimes when i started it it would run fine until i shut it off. other times i would start it and put it in drive and missfire like crazy.

glad to hear a flashing ses light means missfire so hopefully i can rule out a bad fuel pump.

im letting the car cool down on jack stands now, later i'll inspect the plugs and wires and connections at the opti and coil. i have a HEI spark tester i bought a month ago when i first encountered this problem, but then it "went away"

Bigtoyz

iTrader: (2)

I dont know if it is kind of the same issue or not. But my car has been kind of hard starting all of a sudden. Just needed to crank little bit more than normal, but still started.

Well I went to take my car to be tuned. Had to stop and a store for the wife first. Went to start the car and wouldnt start. Didnt hear the pumps prime up. So thought it was the relay. bypassed the relay and pump ran. But pressure went up to 60 psi so I tried starting it. It wouldnt so I figured it maybe flooded. So we pulled it to where it needed to go. A buddy of mine mentioned he has fixed some blazers with same kind of issue but was the oil pressure switch that cuts off fuel if you have a roll over when you loose oil pressure to stop fuel fires.

Does anyone know where this is located to test. And maybe it could be your issue also. Didnt mean to get off topic if isnt.....

Bigtoyz

iTrader: (2)

Found where it is at in back of the intake underneath the fuel reg.

BadBirdie

after checking all the connections to spark plugs and to opti, all plugs are tight, wires are in good condition. connections all seem good however i did notice some residue on the wires where they connect to the opti on the passenger side that might have been coolant leaking from the water pump. this is my dd so im going to have to start throwing parts at it unless someone can help.

SilverSS07

iTrader: (1)

Find out what the codes are; that should help some. ICM you should be able to have tested at a parts store. Ohm the plug wires to make sure they're good. Inspect spark plugs. Ohm coil. There's a thread on here of how to diagnose the opti. Do that.

Catmaigne

iTrader: (6)

Scan before you jump to conclusions. It could be something as small as an O2 sensor.

mezzyshreder

Scan for codes before you do anything.