HELP! I think my Opti is gone

[92LRC]

Yesterday while I was out on a drive the car stuttered and stalled. The Service Engine light came on and off. I got it restarted and it did it again a couple of blocks later. I finally managed to restart and got it home about 5-7 miles from where it stalled with no further incident. When I got it home I started and stopped it a few times without a problem, no service engine light.

This morning I got out the papeclip and this is what I got:

1.1 - H74 - LED Display Open - I have no idea what this means
4.1 - H16 - Opti Spark Low Resolution (Fuel)
4.1 - H36 - Opti Spark High Resolution (Timing)

Right now the car is turning on without a problem and not throwing any codes.

Could this have just been a one time thing or am I destined to have to replace the Opti? The PO had it replaced along with the water pump right before I bought the car 4 years and 12K miles ago.
Any info is appreciated. Thanks

 

[kraz]

i had the same problem it turned out to be a faulty gas gauge reading fuel sending unit and bad fuel pump and fuel filter kraz

 

[Schrade]

Yesterday while I was out on a drive the car stuttered and stalled. The Service Engine light came on and off. I got it restarted and it did it again a couple of blocks later. I finally managed to restart and got it home about 5-7 miles from where it stalled with no further incident. When I got it home I started and stopped it a few times without a problem, no service engine light.

This morning I got out the papeclip and this is what I got:

1.1 - H74 - LED Display Open - I have no idea what this means
4.1 - H16 - Opti Spark Low Resolution (Fuel)
4.1 - H36 - Opti Spark High Resolution (Timing)

Right now the car is turning on without a problem and not throwing any codes.

Could this have just been a one time thing or am I destined to have to replace the Opti? The PO had it replaced along with the water pump right before I bought the car 4 years and 12K miles ago.
Any info is appreciated. Thanks

Good job checkin' DTC modules . Don't erase them just yet.

You don't want it to be a 'one-time' thing. Machines that do that are not dependable.

Check FSM for each DTC. Each one might say to check for another code FIRST, and it might be a simple fix.

Not lighting up any code now MIGHT be because it's cold. Cold diagnostics don't happen.

 

[92LRC]

Good job checkin' DTC modules . Don't erase them just yet.

You don't want it to be a 'one-time' thing. Machines that do that are not dependable.

Check FSM for each DTC. Each one might say to check for another code FIRST, and it might be a simple fix.

Not lighting up any code now MIGHT be because it's cold. Cold diagnostics don't happen.

Going thru the FSM now. I'm going to let it warm up tomorrow and see if things pop up when it gets hot.

Thansk

 

[gmjunkie]

Yesterday while I was out on a drive the car stuttered and stalled. The Service Engine light came on and off. I got it restarted and it did it again a couple of blocks later. I finally managed to restart and got it home about 5-7 miles from where it stalled with no further incident. When I got it home I started and stopped it a few times without a problem, no service engine light.

This morning I got out the papeclip and this is what I got:

1.1 - H74 - LED Display Open - I have no idea what this means
4.1 - H16 - Opti Spark Low Resolution (Fuel)
4.1 - H36 - Opti Spark High Resolution (Timing)

Right now the car is turning on without a problem and not throwing any codes.

Could this have just been a one time thing or am I destined to have to replace the Opti? The PO had it replaced along with the water pump right before I bought the car 4 years and 12K miles ago.
Any info is appreciated. Thanks

Aw Heck,Let's just Blame the Opti and start throwing Expensive parts at it!!:L:L:L(Or as "Schrade" calls it,Attack it with the "Fully Loaded Assault Wallet")
Truth is, it seems like everybody wants to Blame the Opti first and in my experience,I seldom ever replace one!!(Have had to replace Cap and Rotor though!But I don't think thats your problem!)
1. grounds,Grounds,GROUNDS! High Resistance or Non Existent grounds make Electronics do weird Sh*t!!
First I'd check every Chassis and Engine Ground................
Starting at right frame rail below AC evaporator housing(1),Front of engine around Coil and Ignition Module(1),Right and Left Frame Rails below Head Lamp Assembly's(1-2 Each),Left Rail by Radiator(1-3),Behind Battery on Rail(1-3),Second Bolt up on left side of bell housing(1Ground strap,2-3 wires from Engine harness,Above Oil filter on side of engine(Batt Ground cable/and 1-2 from engine harness,(Check condition of Battery cable ends while your there!) Behind Left rear wheel on Frame Rail Ground Strap to Radio Antenna, and I believe there are 1-2 from Rear Body Harness attached to Antenna housing!! Some years are attached at G strap on antenna,Some are higher up on Antenna housing!

2.Clean and Inspect All Mini Fuses at right end of dash,Clean and Inspect All Maxi Fuses in Power Distribution Center beside Battery on door henge pillar and B + Lug connections on Power Distribution center!!

3.Clean and Inspect wiring Plug and Pins on ECM,Flat Plug to Opti under Right Fuel Rail Cover(Between #4 and #6 injectors!) and Clean and Inspect Plug and Pins on Opti,Ignition Module and Coil! Also check for Chaffing in Main harness from ECM to Flat Plug between Engine and Cowl!
Dump the Codes and Road Test and see what pops Up!!

PS. I'm Not saying that it's Not the Opti,Ignition Module, or Coil,But in my Experience this will usually fix it more than 90% of the time!

Good Luck,Gotta get out the sticks and strings and check the alignment on my 03 Spiral Grey,I have to go on a road trip to NE Missouri to see Mom!!
Happy Vett-ing!


Be American,Buy American!!

 

[92LRC]

I've always enjoyed your posts Junkie, thanks for the heads up on the grounds. I'll dig in and see what turns up

 

[gmjunkie]

Clean and Inspect All Maxi Fuses in Power Distribution Center beside Battery on door henge pillar and B + Lug connections on Power Distribution center!!

Sorry,I just remembered that 92 LT1's still had Fusible Links there!! But Clean and Inspect the connections anyway!

I've always enjoyed your posts Junkie, thanks for the heads up on the grounds. I'll dig in and see what turns up

Good Luck!!

 

[92LRC]

OK. I checked the connectors/wires and I don't see any obvious signs of corrosion or any nicked wires.
It finally stopped raining so I took it out for test ride today.
Started up like a champ. No SES. I waited till it got good and hot and I took it around the block a few times. Not stuttering, no stalls. I figure I'll get braver over the weekend and take it for a longer drive and see what happens.
Thanks for the posts and suggestions. I'll update over the weekend.