I've got two questions. 1) I've got a 96 Bonne that acts very strange after a warm start. The RPM flutters around 1500-2000, the check engine light comes on. After 15 seconds the RPMs go up to 3000 then down to about 1100 where the engine begins to run smooth again. This only happens unpon a warm statr-up.
2) Is there any way to flash the codes other than with a scan tool?

Thanks!!

With the engine off, pull the vacuum line off the fuel-pressure regulator on the fuel rail. If gas comes out, the regulator has a broken diaphragm and is leaking gas into the vacuum system. The symptoms you describe fit this problem (among others ) My '96 Trans Sport was doing the same thing. (Cold starts were always okay.)

And you need an OBDII compliant scantool to read the codes.

There is no other way to get codes On a OBDII other than a scantool.

I have had similar problems on hot days, generally after I park it with a 220* engine. This go the same for a SC engine as well (the vacum / fuel thing mentioned above)?

Could be. Heck, you only need 10 seconds to pop the hood and pull the vacuum line to check, so go for it.

Har Har

Keep in mind that gas may not come out the regulator and the regulator is still bad. The procedure to check it involves seeing if it will still hold pressure. You pressurize the system (turn the key on without starting), when the pump stops making noise, crimp the gas feed to the fuel rail and see if the pressure drops. If it does the regulator (or an injector) is leaking. There'* actually a complete procedure to check the whole fuel system, I can type it out if anybody is interested.

Which brings me to a question to the group. On other cars I've worked on there is a rubber section somewhere in the fuel line you can crimp to block off the feed (or return). On my Bonneville there are no rubber sections in the fuel line. It'* all hard tubing. Has anyone figured out how to do this without buying the special tool the shop manual recommends?

I did a rebuild on my SC a couple months ago and there were rubber lines on the back side of it running above the rear valve cover. I remember this because I had them pulled up and over my stabalizer bar while I was doing the work.

That'* odd. Mine are hard plastic. I can move them around, but I would be afraid they would crack if I crimped them with locking pliers for a test. Maybe it'* something unique for a '93.