'95 88 3.8L intermittent stalling/missing -- No codes

[RickyJP]

My 1995 Olds 88 Rolale LS seems as if it is missing at intermittent intervals/times. No check engine light and it seems like it is running out of gas, like something fuel related.

The car has 105K miles, AT, non-turbo. On 1 occassion it sat for a few months without much driving. So I decided to start easy -- plugs, wires, fuel filter, air filter and have moved on to fuel pressure regulator and fuel pump. I even cleaned the Mass Air Flow sensor and poured a can of Heet in the tank. I use BG44K about once a year too.

Now 2 different Auto Parts stores have OBD II readers that cannot communicate with my ECM. Strange because about a year and a half ago my buddy hooked his up to find that I needed a new Oxygen sensor. Now I cannot communicate with the ECM at all. I believe that both OBD II readers used by the parts stores to be multi-protocol so I really do not know where to try next.

Also, to ensure that the ECM can throw a code, I unhooked the EGR (easiest connector to get to) and the check engine light did finally come on. I love the car and really need some more ideas.

Thanks in advance for any assistance!

[maxwedge]

Welcome to AF, the parts stores scanners will not work with the transition year 95 cars. This requires a scanner programmed for that application. There are a multitude of conditions that can cause your symptoms, bad wire, coil, injector, some sensors and more. A full scan is the first step.

[RickyJP]

Thanks, I keep hearing that 1995 is a tough year. I noted a sticker under the hood that says OBD I compliant, yet I have an OBD II connector. I will go to my buddies shop tomorrow to use a better diagnostics tool. Will keep posted here.
-Rick

[RickyJP]

We finally got an OBE reader with the correct cable and no codes were pulled. To further check the OBE functionality we pulled the EGR connection and the reader reported a faulty EGR connection.

We looked at on-board data and ALL appeared to be nominal.

I am wondering if perhaps the crank sensor MIGHT cause this problem. A review of the schematics make it appear that the crank sensor feeds only the Ignition Control Module and not the PCM.

Could this make it run rough but not read a code? Wondering if anyone has any other thoughts.

[maxwedge]

Running rough as you describe is usually not an issue caused by the cps. a 95 car will not seset a code for misfire. So it is possible a plug, wire or coil could cause this as well as dirty injectors, Can't tell you where to start without onsite diagnosis. disconnect the egr and see if that helps, put a bottle of Chevron Techron in the tank and run it down as per instructions.