Haven't caught up completely... But there'* a few thoughts I had.

First: A GM fuel gauge reads "F" when full? *EVERY* GM I've owned has pointed to "5/4" when the tank is full. In other words, every GM can miraculously have a full-and-a-quarter tank.

Second: Most cars are built with a "reserve" in the tank, for instance, a 16-gallon tank can be 16.8, 17.2... Crazy numbers like that. Most of the time, the listed capacity for a gas tank is the usable volume ~minus~ the reserve. And some GMs have the fuel pump in a plastic sump area that is separated from most of the tank, with a few small holes drilled in it for the gas inside the tank to enter the sump area. It'* not uncommon to have 2 gallons in the tank and not be able to start the car when facing either uphill or downhill.

My '87 LeSabre can have up to 5 gallons in it and display "E" on the gauge, dimly illuminating the "Low Fuel" light, when parked nose-downhill. I can then pull out onto a level street and watch the light fade out and the gauge creep up to 1/4 or 3/8.

A friend of mine had an '82 Chevette (LOVED that car!) that, when full, read overfull-by-half, and empty was below E. And, when you made right turns with less than 3/4 a tank, the gauge would drop to E and then return to normal. I've also seen an '85 Chevy C-20 pickup that, after many years of flawless service, randomly decided that Empty was Full, and Full was Empty. Once you put a sticker on the bezel to swap E and F, you could completely trust that gauge.

Gotta love GMs.

One thing to consider is how... uh... awkward the OBD-1 relearn sequence is. I wonder if, during the relearn, you touched the throttle to try and clear up the idle problem? I've had issues with OBD-1 relearns if, in the first few starts, you fiddle with the throttle.

I'm trying to think of my '88 Cutlass Ciera - I had the 2.8 MPFI - I had to do two or three relearns once before it got it right. And we won't talk about the relearn process on my mother'* old '87 Pontiac 6000 */E 2.8... That thing had to be constantly reset in order to run!

At the top of your TBI there is a rubber connector with multiple vacuum lines going into it. There'* a darn good chance that has gotten weak with age, and the barbs that hold it snug inside the metal ports are worn. Check those for leaks (even if there'* nothing wrong now, just as a preventative measure) and, in a pinch, you can wrap one single layer of electrical tape on the barbed spots to keep the vacuum lines in place. It'* a common 2.8/3.1 MPFI problem I've seen.

I remember you mentioning a total lack of dash lights, with the exception of the "idiot lights." I *think* your car has the rocker switch with two separate upper pieces (Parking and Headlamp) and a wider bottom piece (that turns either mode off) with a thumb-wheel for the brightness of the dash, am I correct? And hopefully analog gauges...

If I am, here'* what to check on that particular system:
1. Check your "Inst Lp" fuse. This fuse runs your entire dash lamps, including the OEM wire for radio illumination, ash tray lamp, HVAC, possibly others. Also, take a brief inspection of the wiring - it'* common for the ashtray lamp wire to chafe against the ashtray frame, dash supports, and radio. This is a common area for shorts.
2. All bulbs? (#194/#168 most likely, with a few #74s possibly)
3. Illumination "membrane" on the back of gauge cluster is toasted. This is two clear plastic sheets with metal "wiring" sandwiched between them. Also, check for filth/corrosion where the sheets touch the wiring harness (being an '88, the plastic probably presses against the harness plug and it relies on a clean contact point and firm securing of the gauge cluster to the dash to make that connection)
4. Defective headlamp switch. These suckers wear out after a while, and aren't too expensive. They are so common, the same exact switch was used in many GM models, and Jeep Cherokees and Commanches. Yours may have an integrated dimmer module, or the dimmer may be separate depending on the car.
5. Your car MAY or MAY NOT have a small power transistor hidden away in an awkward spot in the dash that converts the varying voltage from the dimmer switch to a varying amperage to power the dash lamps. They did this to ease the strain on the dimmer switch for longevity purposes. I had this fail on my '94 Cavalier, but I don't know of any other vehicles that have this item.

If you have a digital dash that won't illuminate, chances are almost 100% it'* the power supply in the gauge cluster. Check out eBay or the internet for companies that professionally rebuild digital clusters, you will most likely end up with a better-than-OEM rebuild that they can set to your current mileage in exchange for a small fee and your old cluster (which will be rebuilt and resold) or they can rebuild your cluster. You can try boneyards, but those are typically as-is no-return, and who knows how long it will last (if you can even find one for an '88 Regal).

If you have to get inside the dashboard, you will ABSOLUTELY need a 7mm socket, a 1/4" drive ratchet, a few extensions as necessary, possibly a T-10 Torx bit, #2 Philips screwdriver, and having a 7mm nutdriver would be a great help too.

I've been inside way too many GM dashboards, way too many dashboards in general, so let me warn you: there are *MANY* sharp edges and really tight spots (not to mention hidden screws) inside the dashboard, so take your time and go easy. Don't use a power screwdriver to put anything back together, these dashes get brittle with age. Keep track of all your screws and where they go, don't force anything. If you have a column shifter, take a pencil and mark where the tiny little metal clip from the indicator clips onto the steering column (this way you can line it up properly when you throw it all back together). And you will most likely have to stand on the brake and shift to L1 to remove the gauge cluster - and if you have tilt steering, you'll want to position that lower for extra clearance.

It'* more time-consuming than complicated. LOL

Hi, Andy. I didn't get an Email notification that anybody posted on this thread. I got so tired of working on this car last summer that after I got it running I didn't want to see any mention of cars for a while. hehe. Anyway, thanks for your detailed write-up. I especially liked the part about sharp edges around the instrument cluster area, because I think I cut my finger when working on the dash.

The dash light problem turned out to be a bad headlight switch. Everything works in the lighting area now. Still no speedo most of the time. I'm thinking the VSS is bad there.

I've been driving the car for a few months. It'* been reliable until about three weeks ago; it got hard to start again. Almost all of the sensors were replaced last summer along with the injectors and fuel pump.

The possible problems I'm considering now are, the CPS, EGR, and Ignition switch. As soon as it warms up and dries up outside, I'll check some of those things.

I think the first thing I need to do is add some Thermo-aid (NAPA) to the gas tank. The car has been through many temperature swings without any preventive measure in that area.

The Ignition switch may need to be replaced due to age. I don't think it'* a problem at this point, because the car doesn't shut off; it'* just hard to start.

After treating the fuel tank, I'm going to check the Crank Position Sensor. It doesn't have very many miles on it, but it seems like it could be a cause of the symptoms.

The newer EGR (NAPA - replaced last summer) has very, very few miles on it, but it was on the border-line of being bad during a vacuum test after I installed it.

I'm thinking the reason I need to put the gas pedal to the floor during start-up is because of moisture in the gas. Well, I guess I'll think that way until I get some fuel additive in there to eliminate the possibility. Maybe putting the pedal to the floor makes less difference than the extended cranking time does. I'll test that theory the next time it doesn't start by not touching the gas pedal.

if your crank sensor is messed up no spark or weak spark can occur which would cause flooding, which would be helped by flooring the throttle as it shuts off the injectors

the fuels around here have winter stuff in them already, so unless its sat quite a while im not sure fuel is the problem

Excellent input JW! Would it not shut the engine down occasionally if the CPS was bad. Once the engine runs, it hasn't shut off yet. Of course, the symptoms could vary greatly with a bad CPS, I think. Altough I haven't put more than 25-50 miles on it since the problem got worse, it might not have been driven enough or gotten bad enough to shut the engine off yet.

Do you not put any additive in your fuel tank that far up north?

i only get 28 instead of 32 mpg because of the winter crap they put in there. i had a 90 GP that had a 3.1, basically like yours and it had the crank sensor go. it took me 5 or 6 months to figure out what was going on. ( we didnt have internet back then) at first it would start fine cold everytime then if i left it at the store shut off and tried to restart it it wouldnt start so i would call the tow truck and if they came quick it still wouldnt start but after i got home it would start fine. so after a while sometimes it just wouldnt start or it would take a while. so one of the times i got told he said its the cps just replace it. for as cheap as they are i did and that was it. its just a pain to reach and try to get out

I'm not sure what kind of fuel blend they have around here. The reason I was thinking of a moisture problem was, when it started freezing outside, the fuel pump would keep running when trying to start the engine. You could barely hear the pump but it definitely kept running. The engine wouldn't start while it was running either. I figured there were ice crystals clogging the line. After a few seconds and turning the key off and on a few times, the pump stopped running. I usually keep a full tank, but I had a half tank for a couple weeks during temp. swings. I don't drive this car much either.

When my CPS first started going bad a couple of years ago, the engine shut down while driving, it started after a few tries and didn't have any more problems for several months. It shut down while driving 1 more time then eventually got to where it wouldn't start without pressing the gas pedal down a little. After replacing the CPS, it ran OK for a few more months then the big Fiasco set in. There'* not that many miles on the CPS, but it acts like it'* going bad. Maybe your in-laws Buick has a CPS problem too? It is a pain to get out in the snow here for the CPS. That'* why I haven't done it yet. Gotta get that truck out of the garage one of these days.

hard to say at this point

Haven't caught up completely... But there'* a few thoughts I had.

First: A GM fuel gauge reads "F" when full? *EVERY* GM I've owned has pointed to "5/4" when the tank is full. In other words, every GM can miraculously have a full-and-a-quarter tank.

Second: Most cars are built with a "reserve" in the tank, for instance, a 16-gallon tank can be 16.8, 17.2... Crazy numbers like that. Most of the time, the listed capacity for a gas tank is the usable volume ~minus~ the reserve. And some GMs have the fuel pump in a plastic sump area that is separated from most of the tank, with a few small holes drilled in it for the gas inside the tank to enter the sump area. It'* not uncommon to have 2 gallons in the tank and not be able to start the car when facing either uphill or downhill.

My '87 LeSabre can have up to 5 gallons in it and display "E" on the gauge, dimly illuminating the "Low Fuel" light, when parked nose-downhill. I can then pull out onto a level street and watch the light fade out and the gauge creep up to 1/4 or 3/8.

A friend of mine had an '82 Chevette (LOVED that car!) that, when full, read overfull-by-half, and empty was below E. And, when you made right turns with less than 3/4 a tank, the gauge would drop to E and then return to normal. I've also seen an '85 Chevy C-20 pickup that, after many years of flawless service, randomly decided that Empty was Full, and Full was Empty. Once you put a sticker on the bezel to swap E and F, you could completely trust that gauge.

Gotta love GMs. [/QUOTE]

I had a '78 Checker that was mainly GM drivetrain, the needle got more miles traveling up and down in the gauge, then the car did...my mother'* Chevy minivan does the same thing. Guess its a GM thing.

How are the connections on the Coolant Sensor? Are they fairly well dry rotted? I couldn't remember if you said you'd replaced them or not. Also what about the fuel pump relay? Is it sending signal to the pump longer than necessary? Unsure about the control modules, any way to do a flash and start over?