OK, let me first start out by saying that i'm a NewB, so go easy on me. I, however, am an avid pontiac fan and also own a complete custom 1994 Trans Am with a 383 stroker which i built myself and race at the drag strip, so I know my way around a car.

That said, I LOVE my bonneville, it'* my daily beater which I drive to and from work every day. The reliability of this car is USUALLY superb. It'* got 262,000 miles on it (40,000 of which I put on) - I paid $600 for the car and have put little else into it in 2 years besides a wheel bearing, and a fuel pump, big deal. I figure the car is already on borrowed time, so if this is the end for her, then may she rest in peace.

So, I live in wisconsin, you can keep that in mind. yes, it is cold up here, around low 40'*.
Lately, within the last couple months or so, the car began this wierd issue where, you give a decent amount of throttle, say, to pass someone, it downshifts, you make the pass, and then it wouldn't want to shift back into OD, or it may not have shifted back at all. It got so bad a few times, that I'd leave for work in the morning and the car wouldn't shift past 2nd gear for maybe the first 5 minutes of driving. Here and there it would trigger a check engine light. I had the car diagnosed to be a TPS sensor, which I replaced. The problem seemed to stop.

A couple weeks after that it started to come back, with a hit or miss check engine light. ALSO for some reason, sometimes it does this bad high idle thing for about 10 minutes or so after start-up, where it will stay at about 2500 - 3000 and if i drive it i have to MASH the brake pedal to get it to come to a stop b/c there'* so much throttle being applied. I can't expliain this. It acts like an old school mechanical Choke on a 1980'* vehicle where you have to let it warm up for 5 minutes before it idles down. Wierd.

ALSO, and worst of all, is this crazy stumble it gets, it will idle fine, but then you drive it away, give it SMALL amounts of gas and it'* ok. If you try to give it like 50% throttle or more, it starts choking and coughing, sputtering, missing, and just plain old won't accelerate at all. Today, I had to FLOOR it to reach 50mph on the way to work. The other day, it wouldn't start, I had to spray it down with starting fluid to get it to fire up. It was like on the verge of starting but just wouldn't really fire up.

I don't get it, this car has really NEVER given me any problems before. Due to the fact that it'* got so many miles and that I haven't paid much for the car, i was just thinking about getting another car b/c I don't want to dump a bunch of $$$ into a car with 1/4 of a million miles.

I was hoping someone on here may know if these symptoms are common of a specific issue or if the whole thing is just starting to fall apart. I was thinking maybe a bad coil or ICM. The fuel pump was replaced about a year ago so I wouldn't think it could be a pressure issue unless the filter is clogged. I could check the pressure at the shrader valve.

I was wondering if anyone has any ideas. This seems like an electrical problem maybe somewhere in the ignition. Please help!
Check engine lights are hard to diagnose. It'* got that wierd, OBD II style ALDL connector, but with an OBD I computer (being that it'* a 1994) Autozone and the like, can't scan it, so every time i have to get it scanned, i take it in. that'* a nice $90 fee for 5 minutes. And since it'* an OBD I it doesn't store the codes, so you have to drive it on in WHILE the light is on. Since the light RARELY comes on, it'* difficult to just drop everything and drive to a dealership when it does. Unless anyone knows how to jump the connectors to get the SES light to flash the codes out, which i have done before in other vehicles

Sounds like IAC.

Other than the TPS - what else has been done to the car? Plugs, wires, oxygen sensor, etc? If those haven't been done for a while - would be a good start. Remove the throttle body (you'll need a new gasket), and give it a good cleaning. Remove the idle air control, and MAF sensor, and clean those well, too. Directions are in techinfo. Be very careful with the tiny MAF wires. Many have had luck using a spray MAF cleaner, but make sure what you use is safe for that. Check all vacuum lines for any leaks or cracks. Let us know how those things work out.

Regarding the diagnostic port (OBD1?). Does it look like this?

If so, there is techinfo at
http://www.bonnevilleclub.com/forum/...e=article&k=57

Sorry - '93 was the last year that you could pull the codes by jumpering terminals on the ALDL connector, on the Bonneville.

94/95 have OBD2 connectors. Ignore the picture and procedure above.

After re-reading, now I understand. What a bummer. Never knew some won't store codes. Yeeeshh. Learn something new everyday. Wonder if there is a way to ID the Diagnostic Terminal pin and ground that, what with having an OBD1 computer.

Sled, they ALL store codes. Retreival is different.

No, you can't ground pins to do that. The function isn't built into the PCM after 93. Let'* get back on topic please.