Help my Riviera is bogging down!!!

[Guest]

Hey I know this site is usually for antique Buick's but I really need help and we have alot of experts on this site. My problem is that my car is bogging down while I'm driving, I can be going 40 or 50 mph and then it will bog and even if I push the pedal to the floor the car doesn't go. Most of the time it happens when I'm at a light and I stop when it's time to drive again the car struggles to go and from there on it drives really bad. There are times where it will not go over 25mph, it also happens alot when I have to turn. My thought is that I may have a bad Oxygen sensor. I'm not sure if this a logical diagnosis. Please help me any advise will be very helpful. Oh, just a bit more info. I installed a new fuel filter about 6 months ago so that should be in good working order unless it's clogged or something.

[Turbo Loyd]

[color:\\"blue\\"]Hi BuickGirl

I'm assuming the 1988 Riv has the 3800 engine with Mass Air Flow (MAF) sensor. Does the car use a lot of fuel and create black smoke?

When my GN acted like this the MAF sensor had gone bad. This sensor tells the computer how much air is going into the engine. When it is bad the computer does not have this information to add the correct fuel. If there is an air leak between this sensor and throttle body the same thing will happen. Failure of the sensor or air leak may not create a code that turns on the service engine light.

A simple test would be to unplug the wire to the MAF sensor. If the car runs better in the so called "limp home mode" it may be the problem. To find the sensor follow the tube from the throttle body to the air cleaner. It is the black plastic unit about 5 inches long that is clamped onto the tubing, with the wires hanging out.

Just one of many possibilities

[Guest]

Yeah my car has the MAF sensor I'm going to go check that out at my lunch time. I wouldn't say my car uses alot of fuel, I get about 15 miles per gallon that does not include highway driving. I've never seen my car expel black smoke. I checked to see if there was an air leak in the throttle body already but everything looked good. Occasionally my car will bring up an error that says "Electrical Problem Detected". I have a screen in my car like a little computer and it will turn on the check engine light. But this doesn't happen everytime the car boggs down. It's kind of sparatic. Thanks for the info!

[Smartin]

You don't happen to have a K&N air filter on there do you?

[Guest]

Yes I do have a K&N filter how did you know?

[Smartin]

I replied to your PM...

A K&N filter has oils in it that clog the sensors on the MAF that was mentioned in one of the above posts. This will cause the computer to read incorrectly and create a lean(?) condition.

[BUICK RACER]

Another thought is to post on the Reatta discussion board, as they had the same engine and similar computer interface in '88 web page

[2seater]

I have never known of a K&N filter to cause any problem with the MAF, I've had one for years, and the GN guys use them all the time, although the MAF is a different style, also goes for many other makes that use a MAF sensor? The first thing to check is the fuel pressure. The "electrical problem detected" could be many things, even poor charging or battery connections. Can you read trouble codes through your touch screen? A failing coil pack or ignition module will usually not set a code but will give symptoms like described. The last item which is showing up more and more, apparently due to age more than mileage, is the ECM itself, which doesn't self diagnose either. Essentially, there are many things that can cause a loss of power, if the air stream is open and clean, the next thing is fuel, then spark and finally controls for the above. The engine will run with almost all sensors disconnected, as the computer will revert to stored values, so the suggestion of disconnecting various sensors to see if it changes the way it runs is a valid one. Also, disconnect the battery and check the connections, particularly the + for corrosion. This is a common problem that is well hidden by the side terminal connectors. Also check the main stud on the alternator is clean and tight. Disconnecting the battery will also reset the ECM to default values so the engine should run differently, maybe better, and the sensors will come on line when the temperature is high enough to go into closed loop operation, and it relearns operating parameters. The O2 sensor usually shows up as poor mileage, and usually doesn't have the magnitude of effect on driveability you describe.

[Guest]

Although I know of many people who have the K&N filter and do not experience any problems I can say that my fiance had experienced the same thing in his car and it was a 2000 Honda Civic Si. It did it alot worse than my car, he eventually replaced the O2 sensor and kinda figured that it was the problem. It never happened again after that. But that was only about 3 months ago, so maybe the sensor was just clogged or something. I will check my fuel pressure though, and I am changing the battery terminals due to corrosion tonight. Yes I can read the trouble codes through my touch screen so I will run the codes tonight and see what it comes up with. My coil pack is fairly new except for the base of it which is the original one. I can only get that through a junk yard I think. I will clean all my sensor connections and see how the car runs. SO!! I have alot to do tonight thank you for your input. It is greatly appreciated.

[Smartin]

For some reason, I am unable to respond to your PM. I keep getting error messages. But you're on my buddy list now I wasn't home when you IM'ed me.

[Guest]

Well even though you got that error message I got your message 6 times. SO it was still going through. I'll IM you later tonight. Your on my buddy list too so I'll see if your online.

[Smartin]

hahah

I kept hitting the back button and tried sending multiple times. I guess they all went through!

[Guest]

Hey, just to keep everyone informed I replaced my oxygen sensor cause it was so cheap. But it didn't make a difference in performance. I cleaned my MAF sensor, and that didn't make a difference either. Now I'm at work and I went out to get a bite to eat and it would not start. It turns over but will not start I'm going to have my fiance come and check my fuel pressure. I don't think I'm getting adequate fuel. The next thing to check I guess maybe my fuel injectors, Does that sound logical?

[55PackardGuy]

Sounds most logical to me. If you happen to have a plug wrench handy, pull one of the plugs after cranking to try to start it. A dry plug would indicate not enough fuel. It's an old trick, but still can provide vital info.

[2seater]

It sounds like whatever the problem is has reached the point where you will be able to find it. The '88's had a bit of a problem with the cold start priming shot was not enough to start the car. If you turn the key on, can you hear the fuel pump runs for 2-3 seconds? If not, either the pump is bad, or the fuel pump relay has died. If the pump does run, try turning the key off, wait 20 seconds or so and turn it on again to give it a second priming shot then try starting the car. No start is either no fuel or no spark. No spark could be the crank sensor, ignition module, possibly coil pack or the ECM itself. The odds of all the injectors dying at the same time are slim, but they are all run by the ECM.

[HurstGN]

Just remove the cover of the service port on the fuel rail and COVER THE END OF THE FUEL RAIL WERVICE PORT WITH A RAG OR SOMETHING ABSORBANT, then press the tip of the schraeder valve. If you have any fuel pressure, the fuel will wet the rag. If the rag is wet from fuel, and the motor doesn't at least kick in a revolution or 2 when starting, then it's prolly not fuel related, it's spark related. If it does kick in a revolution or 2, you may have too low fuel pressure.

For spark related, check the crank sensor first. You'd be surprised how long and far you can drive a car on a bad crank sensor. I drove a car for a week with a bad crank sensor, then drove from Pittsburgh to DC before it finally gave up the ghost. Crank sensor will give hesitation and stumble problems if it's cracked and dangling. If the crank sensor is fine, next look to cam sensor. A cam sensor can become loose and move, changing timing and eventually a no start condition. Test the cam sensor by gently turning it. It should not turn at all if it's still tight in place.

Hope these tips help

[Guest]

Thanks everyone for your input, I just got a snow storm here in NY but I'm still going out to check my sensors. I am also putting a fuel gauge on it today to see how my pressure is. I will definitely get back to all of you and let you know what the problem turns out to be. I'm not giving up on my "Rivy".

[Gene Brink]

Had a similar problem with my '88 Olds with the 3800 V6. Turned out to be the ignition module. Intermittently the engine was only running on four cylinders. Noticed gasoline smell in the oil so knew the injectors were pumping fuel but it was not being burnt so knew something was off with the ignition. Pulled plug wires (one and a time) and determined which cylinders were not firing. Had coil pack checked and when it turned out okay had the ignition module checked. Replaced the ignition module and everything is okay a year-and-a-half later.

Good luck.

[2seater]

The cam sensor will not affect the way the car starts. The timing of the injectors pulse may be incorrect, but you can disconnect the cam sensor and the car will start and run. The cam sensor cannot slip on this engine, it his held by a single bolt and is o-ringed into the front cover. The sensor can be bad, or the magnet in the cam sprocket can fall out, but it does not have any effect on spark or timing of the spark. While the crank and cam sensor do use common power and ground wiring, they do not interact.

[86 2dr.ltd]

Same problems can have different symptoms sometimes. Checking for fuel and some pressure at valve is no good. I did this on my 91 Regal last summer. It still wound up being fuel pump. I had 18 PSI, not enough to run right. So use the gauge like you planed on. The symptoms were very doggy loss of power.

Then shortly after that it started bucking like a bronc at steady cruise but would pull under acceleration. First thing I did was unplug the MAF so it would drive. Im thinking it was the MAF but that was replaced earlier. Wound up the inside of my fuel lines actually had corroded into scale rust . This scale let loose and pluged up the pressure regulator. Thats how I found it. I though I was sabataged. So I replaced tank, which was rusty enough on topside to have only one year left anyhow. Sending unit and lines up to filter. Blew back through lines from fuel rail and out came another pile of black flakey pensil lead looking stuff. Im still thinking I'm savataged, but I couldnt figure out how it got through new filter. I cut new filter lenghtwise with band saw and found no particules on output side . I removed fuel rail and it too was chaulk full. So were the input ends of injectors . Im thinkin I'm broke and have a unknown enemy but cant figure out how they got the stuff past the fuel filter which remember was clean on the output side. Anyhow I riped a 2" lenght of one of the fuel lines I removed on the band saw. Sure enough inside there was corrosion and in one spot a flake that was still stuck to the lines. I have never heard of anyone else having this problem.

I cleaned the ends of the injectors my self, dont let anyone tell you it cant be done. Seems to me new injectors was going to cost me 4-5 hundred. Took me 5 minutes to flush them out once I figured out the right tool and kerosene for the job. The right tool was the $30 cambell hausfeld wand pressure cleaner hooked to air compressor that I have had sitting around for years. With syphon hose end submerced in kerosene. Kerosene is the only miracle in a can this shade tree uses

My bet, your fuel pump. Im not saying coil pack or module because you didnt mention skippin just no power so it sounds more air/fuel related. Plug wires and module can be checked with old timing light for eratic behavior or no spark at all. They also sell cheap little things that do similar flashing, I've never seen them used.

Next I would say MAF but when my 91 went bad the car ran great but wouldnt idle, instead stall and that was intermitant. On my 86 Riv, slightly different than your drivetrain, bad MAF created low dawgy power and hesitation, idle was fine.

2 seater, wife went to town once with the 86 LeSabre, shut it off and it never restarted. It was the camsenser, only thing replaced and it never happened again. Maybe because of different ECM system

[2seater]

Maybe on an '86, but it should not do so on an '88 and later. The cam sensor isn't needed to determine the correct firing for #1 at TDC as it fires the plug on exhaust also. The Riv and Reatta share the same manual, and the general operating system. I suppose anything is possible, but it shouldn't have any effect on starting on this engine. I will be very interested to see what turns out to be the problem.

[Turbo Loyd]

[color:\\"blue\\"] For a Turbo Regal ECM the cam sensor is needed for start up. Then the cam sensor may be disconnected and the engine will continue to run in batch mode (injectors fired in pairs) not sequential mode.

The ECM needs to have the cam sensor reference to know which cylinder pair the Three openings in the reluctor for the cranksensor are associated with.

Would the General put a cam sensor in the Series 2 3800 if the signal is not needed for such a reference?

[HurstGN]

I was speaking from experience and the car being DOA on the road. Sorry for any confusion this caused. I'll refrain from further speculation and wait and see the final results of the problem.

[2seater]

The cam sensor is still needed for the proper sequential fuel injection. The crank sensor must be different when they went to the 3800 style engine. It generates two different signals, one has 18 evenly spaced and the other has 3 unevenly spaced and sized slots, which generates the proper signal for the ignition module to determine which coil to fire. It cannot determine which cylinder is on compression, so something more is needed to correctly sequence the injectors. Without the cam sensor, it still has sequential injection, but the sequence could be wrong, it doesn't switch to batch fire.

[86 2dr.ltd]

Yes, I know something was changed in that system between 87 & 88. The LN3-C (VIN C) were memcal right and the earlier LG3-3,LG2-B, and LN7-L were PROM.

Im still waiting for the fuel pressure test #'s. So we can figure this one out. I'd hate to loose a potential Buick driver. These 3.8 trouble shooting problems chases many away.

[Guest]

I haven't had a chance to put the fuel gauge on. Don't worry I'm not going anywhere I'll be staying on the long haul to repair and restoration.

[Guest]

O.K. guys new update about my car. Yesterday I installed a new coil pack/ignition module the car drove great no hesitation or struggling of any kind. <span style="font-weight: bold">BUT</span> then when I got to my destination (my friends house) I was sitting in her driveway and all of a sudden without any warning the car simply turned off. It didn't shutter or anything actually the only reason I realized it had turned off was because I had my hand on the steering wheel and no longer felt the vibration of the engine. So I started her up and when I was pulling out of the driveway it turned off in the middle of the street in reverse. Once I started her up again she drove great all the way home which is only about 2 miles away. Any ideas on this one? Oh and I haven't put my fuel gauge on yet because my fiance picked up the wrong size coupling. So I have yet to see where my fuel pressure is at. Oh I have a question, is my ignition module attached to the bottom of my coil pack, is it the silver part of it? Because my Haynes repair manual doesn't really show an illustration of what the Riviera ignition module looks like.

[86 2dr.ltd]

Yes, its the ignition module that the coil packs sit on. This is great news. Cant help you on the stalling problem. When my 91 wouldnt idle it was the MAF. You need to pull codes, it could be many things, just like the low power was.

[Guest]

O.K. another update, my car was stalling all day yesterday. It is now officially un-driveable it will not stay on. Once it's been turned on it turns off about 10 seconds later. My Fiance is going to check the fuel filter and pump to check for clogs. I even went out yesterday and put in a new ECM it turned out not to be the problem but I'm keeping it anyway. I checked my injectors, just a quick test by holding up a screw driver to them and they all had a nice consistent clicking sound. Maybe they need to be cleaned I don't know. My fiance told me when he took it for a drive it stalled and when he went to the schreader valve there was absolutely no fuel squirting out. He finally got it to turn on by turning the key really fast back and forth until it cranked over. I guess we can safely assume the problem lays in my fuel system. Do you think that putting in gas that has a higher octane can cause these problems? I got into the habit of putting in 93, because I thought it might be better.

[2seater]

Higher octane is a waste of money, unless you have knock problems. The engine will be more responsive with plain old 87 octane, and it "may" start better too. I experienced hard starting several years ago and the first thing the Buick garage suggested was changing back to standard octane. At that time, it did seem to help. Since that time I had a premium fuel chip and added a turbocharger now, so 93 octane is required. The hard starting problem never came back, and it always ran well once started. Regarding the performance question as it relates to octane. Try this simple test, with whatever fuel you are using, try a couple of full throttle starts from a dead stop.When you refuel, try the other grade, and try the test again, preferably in the same place and at about the same atmospheric conditions. I would bet you will find more engine response, (and wheelspin), with the lower octane.

If you didn't get a big stream of fuel when you prime the system by turning the key on, that is no doubt the problem. 40+ psi of pressure has the power to send a stream many feet in the air and you have to be very carefull if the engine is hot or running.

[Guest]

Okay everyone, I have news my fuel pressure is at 20 psi. We have to put in a new fuel pump. The thing is we just put a new one in 6 month ago. So I guess we'll have to do it again, maybe a high flow fuel pump would be a better choice.

[Guest John Chapman]

Food for thought...

Did your problems begin suddenly? If so, I'd be highly suspect of your gas station choice. Your problem sounds much like one I saw a number of years ago. One of my partner's new 1998 Camry started missing, then just stopped stone dead. Turned out the fuel tank was full of gas contaminated with water and debris... which in turn had come from the local Chevron station. Seems he refueled just after the station had received a delivery. The high pressure fuel transfer from the truck suspends all the debris/water that settles in the bottom of the tank, and if you get gas from it before it settles... you get the trash/water, too. Totaled the fuel pump, the filters and fouled the injectors. Moral of the story: If there's a delivery truck in the station... go somewhere else or wait half a day....

cheers,

JMC

[Guest]

Hmm I can't really recall if it was all of the sudden it kinda broke down little by little. It was already driving badly when I began this post now I have been with out a car since this past Saturday. It was more like it progressed into the present problem. I do know that I have debris in my tank from the last time I changed the fuel pump. I saw it in there, I think it has a lot to do with my fuel lines they are very rotted on the outside and brittle. I haven't found any leaks and have not experienced any fuel smell so I didn't want to mess with them. But I this weekend I'll be replacing all the lines and fuel pump at the same time since I'll be in that vicinity. I think the best way to get it all done is to take out one line at a time and shape the new line accordingly and replace it that way.

[86 2dr.ltd]

I have had mechanics tell me to spend the extra and get a fuel pump from GM not aftermarket. However the same mechanic that told me that 4 years ago put a NAPA pump in my Regal last summer . Something to think about anyhow. Also can the fuel pressure regulator cause this problem as well? I guess you are supposed to squeeze off the return line at the rubber hose that is up by the engine. Not sure what the 88 Riv. set up is like as that is the one 3.8 engine I have never owned. Anyhow you squeeze this off and see if the pressure gauge rises. I guess it could go quite high if the fuel pump is strong. I dont think you are supposed to hold the pressure up there. Just a quick pinch with pliers over say a rag to protect hose from sharp edges.

[2seater]

Usually the fuel pressure goes high when the regulator fails, but, it would certainly be worth a try restricting the return line for a test. If there is indeed trash in the fuel system, it may be possible that it could block the regulator open and pressure would be low. 20 psi will hardly run the car, if at all.

[BigFella]

I had similar symptoms on my 70 electra...the fuel lines were brittle and did eventually fail. Little air holes in the lines started showing up causing the same issues you are seeing...bogging down, then all of a sudden it would go for awhile then at certain points it would bog...until one day at a stop light uphill it died completely. There was a local shop right there and they pushed me in and told me the fuel lines were pretty much toast. They put rubber lines in place of the rear 1/2 and that got me home and around for about 6 months. We patched a few more places as the lines broke in different places where it was rusted pretty bad...it has driven without that issue ever since the last line segment replacement we did. Now I just need to order the SS lines and get to installing them! I'm even thinking of flying my best friend/mechanic out to San Diego from the east coast to help me! I know that ticket is cheaper than what some shops have told me!!

[Guest]

O.K. everyone my car is running like it just got off the show room floor. My fiance and I messed with almost everything you can name. When it comes down to it we did not replace the fuel pump. We did pull it out and inspect it we did not find any debris clogging up the pump or filter but my fiance did notice that the pump was not really properly aligned to the sending unit assembly. He rigged it so that it sat inline and we closed up the tank. When we turned the car on the fuel pressure was still really low so he disconnected the regulator's vacuum hose and the fuel pressure went up to normal. So we installed a new fuel pressure regulator. When we turned the car on it was great except for the ECM problem. When we put the new computer in the car was not running well so the computer was not set up properly. It kept saying there was an "electrical problem detected". So we disconnected the computer and the negative battery terminal to reset everything. When we connected everything back up and the car was great except when we noticed it was not reading the rpm or the temperature. We turned the car on and off and disconnected the computer again. We even checked all the wiring but everything looked O.K. So we turned the car back on and I took it for a ride it drove like a dream while sitting at a light the rpm and the temperature began working. Of course as soon as I got home to show my fiance it stopped working. I turned the car off and ran the trouble codes but nothing. Turned the car back on and all was working great took it for a spin stepped on it on the highway and took that baby up to 90 without any hesitation what so ever. In the end I think the problem was a combination of things that caused all the problems. So thank you to everyone for you great input and followup I really appreciate it. Diana

[Guest]

Hey I'm still having the problem with the rpm and temperature not reading. My codes come up as E047 and B334, they both stand for ECM to BCM electrical fault and vice versa. What does that mean? I checked all the harnesses and gave them a little nudge and it still is not reading the rpm or temperature. On my way to work this morning the temp started working but not the rpm, by the time I got to work the rpm was working. The same thing happened last night on one of my test trips. What should I look at? I'm worried if the car doesn't read the temperature it will not turn the fan on and will overheat. Someone please help!!

[86 2dr.ltd]

well first post is great news I'm glad its running. Gauges are on touch screen right ? On my 86 they are but I know that was upgraded by 88. I think you should go post on the Reatta forum. Those guys have the most experience with this electrical system.

About your brake lines, I just cant remember the size it is the typical size and I want to say 1/8" but it seems larger, 3/16th's ?. What you dont know is its actually metric and so are the fittings and the flare is a bubble flare. I think you will have to remove a piece and take it with you to parts store. Have fun

[Reatta Man]

Since you are in New York, and you are getting electrical codes, I would suspect you have a bad ground problem due to the salt they use on the roads.

To check all the grounds, you need a good factory manual. If you don't have a really good factory manual (NO, the Haynes manual doesn't fit the bill) then you have two options. You can go on ebay and probably find one for about $30-45, plus shipping. You can also go to www.alldata.com, and go to the DIY section. When there, you can subscribe to the service for $24.95 per year and get all the technical data that shops get for your car. One of the sections has a diagram and drawings to show you where all the grounding straps are mounted to the chassis, engine, and body. Good grounds are critical for newer computer controlled cars, and you can have a bad ground due to rust between the wiring harness and the metal it is mounted to, but not be able to see it until you remove the bolt.

I'm also going to suggest you do a couple of other things, based upon your car's age and likely mileage.

Since I assume you probably have more than 100K miles on it, I would strongly recommend you get a can of 44K made by B & G products and add it to your gas the next time you fill up and then again every 20K miles or so. This is not some late night infomercial snake oil. This stuff is used by thousands of shops around the country. It will be hard to find because it is usually only sold to shops. It is a super concentrated fuel injector and valve cleaner. The 3.8s tend to loose a couple of the injectors with age, and if they are not too far gone, 44K will clean them up like new. If you can't find it locally, go to www.bgfindashop.com, type in your Zip code and they will tell you where you can get it.

The next thing I would strongly recommend is to replace the crank angle sensor. Your stalling and hard starting symptoms sound just like a CAS going out. Often they will go out occasionally before they completely fail. I don't remember if that car reads the RPMs from the CAS or off of the ignition module, but changing the sensor could keep you from being stranded.

Good luck; keep your fingers crossed for your boyfriend. Maybe he will see the light one day and give up on his imports.

Joe