1990 Riviera - Hard Starting

[dealmaker89]

Would appreciate your thoughts on several problems I am dealing with on my Riviera.

I got this car in May from my father-in-law, who had purchased it new. The car

has been in storage for several years, with an occasional start up, or perhaps a short drive. Over the summer, I have been slowly repairing/replacing some some problem items ( digital dash, air conditioning conversion ) and overall have enjoyed the car ( 110,800 miles ). However, there are two or three issues that I must get resolved.

First, this thing won't start cold without 10-12 cranks. The engine will sputter and cough on the tail end of the crank, but not "take off". When it does, it runs great - also, even I crank several times and then leave it for several minutes, it will start right up. My father-in-law tells me that it has never been one to start right up - he would cycle the ignition several times, the crank it. Frankly, that hasn't worked for me unless I let it sit as I mentioned. Thinking it was possibly a fuel pump, I took it by several of the mechanics I routinely use, including our local Buick dealer. Two of them measured fuel pressure below factory specs ( by 5 pounds ) and wanted to replace. However, I had noticed a number of posts regarding this issue, where the owners have replaced the pumps, and still had the same hard starting issue. My third mechanic, by the way, thinks the pump isn't the problem, and wants to replace the ignition module and coil packs, or replace the PROM.

Second issue. This thing wants to run down the road at 35-40 miles an hour, once I let off the gas. I can brake to a stop without the engine wanting to race, but as soon as I get up to speed, I can let off and the RPM's will remain at 1400-1500. It reminds me of my non-fuel injected cars when they need a new choke pull-off. Would this suggest ignition module/PROM problems?

Finally, on a couple of occasions this summer ( hottest days ) the car, after several short trips around town, would run very roughly for several minutes before if would recover and run normally.

I don't mind spending the $ to get this thing running right, but I hate to replace multiple parts at $400 a shot to not get it right. I also realize that I may have multiple issues going on. I have replaced the throttle position sensor, Idle air control, crankshaft and camshaft sensors in hopes of correcting the problems. Also, on occasion the car will code "65", an EGR solenoid.

What's your best guess?

[JohnD1956]

I would suggest blasting the inside of the throttle body with a carburator cleaner. I had occasion to have the throttle body off my 95 Riviera this summer, 109K, and discovered the inside of the body and the supercharger coated with a sticky substance which I presume was exhaust gas from the EGR valve. I was able to clean mine off the car, but I think if you do this on the car you have to run the engine while doing this.

You said you replaced the idle air sensor. Did this include a needle valve? If not, be sure to spray the area inside the throttle body right in the vicinity of the idle air sensor. Had an 89 Beretta once and had to spray this several times. It alwasy moothed out after doing so but it was a situation where it gummed up several times within a year.

[Reatta Man]

Agree with John, and have a few other suggestions.

Your biggest 'nest' of problems has to do with the gas that has gone bad over time while the car was stored. In a carbureted car, it can create problems. In a fuel-injected car, it can be a real nightmare.

First, if you have any of the old gas still in the car, get it out. You can get a hand pump safe to use on gas at most part stores for about $10. Put the old fuel in a seperate gas can, and don't use it in your lawn mower or any other gas engine. Find out what your local laws require you to do with it, and get it to a recycling center that will take it.

If you ran it through the car, you have gum and varnish all throughout the fuel system, especially in the injectors. This is going to continue to be a problem until you get it all out.

This is why you have a hard starting problem after the car has set. The injectors are fast-acting valves, and should have a perfect seal when closed. When the rubber, nylon or plastic parts get gum and varnish on them, they don't seal and the car is leaking raw fuel into the cylinders when sitting. I would recommend the following steps to cure your problems:

1. Remove the fuel rail from the car, take it to a shop that specializes in fuel injectors, and have it professionally cleaned. My '96 Regal had starting and running problems with about 110,000 miles. Took the rail off, and had a local shop clean them. They do a before and after report. I think one was leaking down, and several had bad spray patterns due to deposits, age and mileage. Got it back, put it on, and it runs like a new car. Best $150 I have spent on it.

2. Replace the fuel filter. Use a quality brand, not the cheapest. This one item can be the reason why your fuel pressure is about 5 PSI too low. When pumps start to go bad, they usually drop about half of their pressure. Cost: $5-10

3. Replace the fuel pressure regulator. It is mounted near the fuel rail, is metal, usually silver, about 1" in diameter and has a vacuum line going to it. It regulates fuel pressure on the rail, and allows excess fuel pressure to bleed off back to the tank. Probably worn out or bad due to deposits, age, heat, or all the above. If it fails, there will not be a consistent pressure, resulting in a lousy spray from the injectors. Cost: about $25-30

4. Replace the plugs and plug wires. Use a good silicone 8MM wire, and the plugs made for that car, not what's on sale at the Mega Parts Store. Cost: $6-7 each for AC platinum, if that is what your car uses, and about $50 for a decent set of wires.

5. Check your cooling system. Yes, your cooling system. If it is not running at the factory temp (should be 195 degrees, I think) then flush it, replace the thermostat (I prefer the new Fail Safe thermostats that stay open if they fail) and replace the coolant. If it runs too hot, have the radiator rodded out at a professional shop, or replace it. A poor cooling system fools the computer, and you could have lots of drivability problems because the computer can't read the engine, or is misreading the engine. Cost: $55 for rodding the radiator, $200 or so for a new radiator, and $25 for chemicals. By the way, on a '90 Riv, the gauge should be pointing straigh up at 12 noon when the engine is warmed up.

6. Run a strong cleaner through the entire system. If you can get it, use BG 44K on the fuel system. This stuff isn't snake oil sold on late night cable TV, it is the real deal. If you can't find it, go to www.BGfindashop.com, type in your ZIP code, and it will tell you the closest place to get it. If there is not a shop close to you, go to www.cambridgeauto.com, click on Ryno Products, and they will ship it to you. I prefer the 44K because it cleans the carbon deposits off the back side of the intake valves, as well as cleaning varnish and gum in the tank, lines and injectors. If you can't wait, I would run three large cans of Techron in a fresh tank of name brand gas. No mom-and-pop cheap stuff; stick with Mobil, Exxon, Shell, Texaco or Sunoco, depending on where you are. Most people balk at this step, but this is something a lot of professional shops do when doing a full fuel system cleaning, or a full tune-up. Do this IN ADDITION to having the rail professionally cleaned, not instead of. Cost: about $20 per can for the BG 44K.

7. If these things don't work then remove the coil pack and then the ignition module. The module is silver, and mounted right under the coil pack. Turn the module over; if it looks like there are air bubble trapped in the plastic, then replace it. The bubble are from the module overheating and partially melting the plastic. New module runs about $100.

Of course, all of these prices are based upon you doing the work yourself. You'll save a ton of money that way; most shops will want $70-85 per hour, and they charge the full book rate for nearly all labor charges.

The 3.8 in your car is one of the best engines GM has ever made. If your engine is not burning oil, it is definitely worth spending the money to fix. Good luck and let us know how it turns out.

Joe

[dealmaker89]

Thanks, guys for the suggestions. I look forward to getting started on them!

[centerman]

Reatta Man, What a thorough description of how and what to do to improve a fuel injected Buick. We own a '92 Lesabre with about 95K. Would you recommend a lot of the same for our Lesabre? Runs OK, but has not been tuned in awhile. Plus we'll be taking it in for Syaye of IL emissions testing soon. Mitch

[Reatta Man]

Thanks for the kind words.

For regular maintenance, I recommend the BG 44K to clean the fuel lines, injectors and remove carbon from the intake valves. If you have not done plugs and wires within the last 30K-50K miles, they need to be done at this point, also. Same goes with the fuel filter. If you are not sure if the plug wires have been replaced, most factory wires have a date code stamped on them. If your wires have something like 05-92 stamped on them, they are the factory originals and need to be replaced.

If you live in an area with very hard water (lots of lime, calcium or other hard minerals in the water) then you may want to consider having the radiator rodded out at around 100K. The best way to judge this is if you see the temp gauge gradually creeping up over the last few weeks or months. You can also do it just to give yourself piece of mind.

My experiences with overheating have been brutal; I had a '90 Riv that had a thermostat go bad at 70K miles and blow the head gaskets and nearly every sensor on the top of the engine. Thankfully, it was under a GM Major Guard warranty, so it cost me $25 for a $2,200 repair. I've also owned two Reattas that both started gradually overheating at around 100K miles, but I think a lot of that is due to the VERY hard water here in the San Antonio area. These are the reasons I believe so strongly in Fail Safe thermostats and preventive maintenance. Preventive maintenance is also cheaper than dealing with a breakdown about 99% of the time.

Good luck with your Lesabre. They are incredible cars for their longevity, and if your car's body and interior are in good shape, keeping it and taking care of it are a LOT cheaper than a new car.

Joe

[centerman]

Joe, Thanks for the tips on maintenance. i like to take a proactive approach and try to do some of the work myself when possible. We have really enjoyed this Lesabre. We bought it 5 years ago with low mileage. The body is another thing. Up here in the rust belt, most of the early 90s Lesabres and Park Avenues you see have terribly rotted out rocker panels. Buick missed something on this one and it reminds me of the early 70s Vegas where the front fenders rusted through in short order. Thanks again for your maintenance tips. I really enjoy this message board and have learned a lot. Mitch