A little background: My fuel pump died a few weeks ago so I replaced it along with the fuel filter. That seemed to fix the problem. The past couple days I let the fuel tank get low (1/4 tank or so) and I was experiencing what I assume is fuel starvation under hard cornering. When exiting a corner quickly I would loose power for a second and then it would come back. Electricity wouldn't go away, it would just feel like the fuel would cut suddenly and drop my revs to idle. No, it wasn't the same as ASR and no codes would come up. Filled up the tank with premium from Chevron (as always) yesterday and didn't notice the fuel cutting out , so I assume that was the problem.

Current problem: Now this morning I started my car then it died a few seconds later and wouldn't start. Cranked fine. I haven't had time to get a fuel pressure gauge hooked up yet, but I hear the pump prime when the key is on. Pushed in the check valve at the fuel rails and got just a little dribble of fuel out. Fuses look good.

Is it possible that I either got a defective pump (Oreilly's) or that sucking air in the pump when cornering with a low fuel tank killed the pump? Or should I suspect something else? After work today I will check fuel pressure and then spark, if pressure is ok.

 

Any codes?

 

Nope

 

Yeah.... should have read your first post more closely..... you mention 'no codes'.

A failing opti will not always set a code, but it is usually not intermittent. Cranking without starting could be the opti (?).

 

Oh **** I hope it's not the opti... What symptoms would that typically cause? No spark?

The other thing I thought about is the rubber boot/cover thing around the gas cap that covers the access to the fuel pump and connections is torn. Maybe water getting in there on the wiring to the fuel pump? Is been pretty rainy here.

 

Yes, no spark.

From another forum... may help:One of the most damaging causes for failure of the OEM GM Optispark Distributor is moisture intrusion. We have documented multiple points of potential water entry into the OEM unit from the front, side and back, in addition to the electrical connection itself. This problem is by far the biggest root cause for most other related Optispark component failures. For those interested, here's what we have observed and documented over many parts of both new, used and failed Optisparks. The first potential locations for moisture and oil intrusion of the OEM unit is on the backside of the case through the sloppy bearing bore clearance and the exposed mounting holes that the internal components use to secure them down to the case. Water is also drawn into the electrical connection at the distributor, the silicone rubber weather pack seal in that connector, (especially on cars with age or that reside in extremely hot climates) and both of the silicon rubber perimeter seals on the distributor cap and around the fiberglass rinite insulator. Most of the time this problem occurs right after a chassis bath at a carwash or when someone washes their engine off and the engine will not start, or misfires badly until the moisture evaporates. As soon as the engine is started, accumulated water in small crevices gets drawn into the unit by engine vacuum and the reluctor wheel slings water all over the bare steel parts and electrical components, causing them to corrode and ultimately fail. The reluctor is a stamped, stainless steel component and does not corrode, but the bearing, bearing retainer, retainer mounting screws, optical sensor screws, rotor screws and the EMI shield are bare steel, to which they do corrode badly. Eventually these components scale and start to flake away to where the debris either gets clogged up in the reluctor windows (causing misfire and Hi/Lo Res. DTC's) or it falls to the bottom of the case to which it clogs the vent tube. Once the vent is plugged, soon thereafter you'll start to feel a noticeable misfire and the poor drivability issues will get worse. Engine oil intrusion has also been observed on vehicle's from which the dist. drive seal in the front of the timing chain cover has failed, forcing oil into these open, exposed holes and through the excessive bearing bore clearances...directly into the case and onto the internal components, coating them. The oil/water sludge deposits cling to everything, especially the optical sensor's photo/emitter windows. Rough engine idle, random misfire, backfiring and engine DTC's soon follow. This problem is personified by a high RPM, high output engine with huge, high power ignition systems. How many times have you disassembled a failed Optispark and found water or oil or rust rattling around in the case? Now you know why. We have addressed these areas of deficiency on the OEM Optispark and corrected them in our design. First, all of the internal component mounting holes are blind and do NOT go through the case, therefore eliminating this point of moisture and engine oil intrusion. Second, the bearing and bearing bore receive an industrial sealant coating around them that serves a dual purpose as both a sealant and to add a retentive property to the outer bearing race to prevent the possibility of it spinning in the bore. Since the bearing has a press fit in the bore AND this sealant applied, it will and has not leaked under vacuum testing. Third, we have completely omitted the fiberglass rinite insulator and it's two respective poor silicone seals with our design. Doing so has completely eliminated one seal altogether from the original OEM design and another potential point of moisture entry. The only perimeter seal that is in our design is for the distributor cap. We have elected to toss the easily deflected, OEM silicone seal in this area, in favor of a Nitrile, re-usable rubber O-ring in it's place that is semi-permanently sealed with an industrial grade of sealant that was spec'ed and purchased from GE Electrical Systems. Fourth, in eliminating the fiberglass rinite insulator with our design, we have also effectively eliminated another point of moisture entry by removing the electrical connection at the distributor itself. Our unit comes complete with a wiring harness that is integral to the distributor and it is sealed with two grommets both on the inside and the outside, including electrical industry grade shrink tube over the top of them. The internal optical sensor connector well is also filled with the aforementioned GE Sealent. Finally the entire wiring harness assembly is attached and GE Sealant sealed to the case by a shrinkable rubber boot that is commonly found in the manufacturing of Formula 1 Racing wiring harnesses. It provides a redundant sealing property, as well as, providing strain relief to wires themselves as they exit the case. We figured that if it was suitable for F1 Racing wiring harnesses to live in the rain, than it would suffice for our application. Fifth, we have relocated one of the internal vacuum venting locations to the top of the unit, which is 160* different offset than the OEM unit. This revised location promotes better internal venting due to cross venting of the case as opposed to localized venting of the OEM piece. This revised 1 o'clock location will not plug up like the OEM unit's vacuum port location, in the unlikelihood of someone driving through very deep water that may partially submerge the Optispark. (I've seen it happen!) We use stainless steel fasteners throughout to eliminate any chance of internal corrosion from moisture vapor that may be present when the engine is shut off. Sixth, we have included a circular, perimeter boss on the backside of the unit that encompasses a Nitrile O-ring that is designed to seal against the timing chain cover. This further adds a level of redundant protection of heavy water intrusion from the backside of the case. If the distributor drive seal in the front of the timing chain cover fails and oil pours into this sealed cavity, oil will not flow into the Optispark case as the OEM unit allowed, because we have added a small .040" weep hole into the 6 o'clock position of the sealing boss, to allow engine oil to flow to the outside of the billet Optispark body. The bottom line is, that there is alot more to this "Optispark" than one might think or see at first glance. We have addressed nearly every possible point of common failure that there has been and corrected those weaknesses with the redesign of our part. We have put a lot of engineering and forethought in the redesigning of this product and we wouldn't bring something like this to market if it wasn't a viable product that will increase ignition durability and performance. I'm not posting here to sell these things, but rather to enlighten the skeptics that seem to feel as if our part is just "pretty" and an "overpriced stocker". You definitely get what you pay for here. If you've held on through this long post, than I thank you for your time. Cheers! - See more at: http://www.corvetteactioncenter.com/....AHDClHfV.dpuf

 

Very helpful info. Let's hope it isn't the opti - I want to eliminate other possible issues first.

 

Fill it up with gas and see...........might have a few years of crud if you did not clean the tank and pluged up your filter or screen again can not see it from here but lets start cheap

 

The tank is full now and when I changed the pump and filter, the lines and tank appeared to be clean. Filter wasn't obviously clogged either.

 

Might help (?):

http://www.mainstreamtopics.com/foru...rt-diagnostic/

 

That's a super helpful thread!

Update: I went to check my fuel pressure and the car started up just fine. Pressure looks good. Guess I'll keep my fuel pressure gauge handy in case it dies again... I'm glad it's running but now I don't know what the problem is :/

 

My brother has a 94 Trans Am with an LT1. So far every time he has had problems with no start or running rough it has been the ICM. The PO of the car had the cap and rotor changed around 100k the car now has IIRC around 175k, and to my knowledge the opti has never been replaced.

Short version
Check the ICM.

PS
The PCM also no longer supplys power to the opti, and it has a 12v switch feed.

 

Stay focused on the fuel issue and not optispark, etc. If the only recent changes were to the fuel system and running with a 1/4 tank of gas then chase down any potential fuel system issues.
HIGHLY unlikely there would be something that would coincidently be causing problems now unrelated to fuel.
Recheck the fuel pump pick up, etc and keep an eye on the pump pressure.....