BRW broke down - engine didn´t start again

Guys,
today I wanted to go some food for breakfast and drove the Buick along the town road. I noticed that the gear changed felt a bit strange as if it not knows if he wants to change or not.
When I arrived the traffic circle and slowed down, the engine was a bit shaking. Some more meters I had to stop to let a pedestrian pass, suddenly the engine stpped by itself. All the lights were burning and I believe to remember that there was a message: Low oil Level, maybe low oil pressure. Because I tried to start the engine immediately again, I couldn´t watch all light exactly due to the traffic situation. The cars behind passed me and I tried to start again. The engine was cranking without any strange noises, but didn´t start again. cranking speed was ok, battery is new. I got out the car and checked the oil level, it was perfect (changed the oil 2 weaks before). Tried starting again, didn´t work. So I pushed the car with the help of an Gentleman to the roadside and called the towing service. One hour later the car was back home again.

When the towing Service arrived 30 min later, I tried again to start and it did ! Anyway we  put the car on the trailer due to my fading confidence. At home, the car started again without troubles.

When I did the oil change 2 weaks before, I noticed thet the oil level sensor cable was not in a good condition, so..so. I fixed it with a tie wrap. Do someone know if it´s possible that if the level sensor fails the ECU will stop the engine to ensure no engine failure without oil? I guess i has to be a small tricky failure , but now i`ve no confidence to move the car more than 100 yards away from home....The car is 94, please refer to that due to probably different data Version if you did experience similar issues.

The pre owner handed me a checking device called Hypertech power programmer with which is should be possible to read the Trouble codes. Unfortunatly, I tried but it didn´t work at all. When i connected it to the car (with ingnition on, but not running), there was no data displayed at all. The power light didn´t burn at all, the status light was blinking. No data on the display. If the device doesn´t work or is broken, is there a possibility to blink out the trouble codes?

Thank so much for every kind of help!

Udo

Additional:
I´ve just found out that the battery inside the programmer is stonedead and leaked. Hopefully it works after that with an new one tomorrow. Anyway, your experiences are greatly appreciated....

Make sure you have good fuel in the car first off.

I don't think the oil level sensor has any affect on how the car runs. Could be wrong though. That light will turn on when the engine is off, and the key is on.

Quick checks:
- Good charged battery, and tight battery cable connections.
- Engine grounds are tight, and in good condition. Especially the 3 small ground wires under the ignition coil, on the front of the left side cylinder head.
- Ignition coil wire, and the terminal ends are in good condition with no signs of corrosion, or spark leakage.
- Fuel pressure, should be at least in the high 30's up to the high 40's psi. (250 kPa -325 kPa)
- To get codes out of an LT1 Buick Roadmaster you can use the Auto Climate Control.
info on that here in this link:
[You must be registered and logged in to see this link.]

Your points all makes sense basically , but remind that my car never has had any troubles with starting till this event this morning. If there´s a problem with ground whereever or with fuel pressure, it would be present now yet always. It ran since May ( when I put it into traffic) without any Problem until this morning when it broke down. After half an hour it started again to climb on the trailer and started at home again. It seems theres an electrical problem what comes up and disappears apart from those "typical" troubles as poor ground, bad sparks, low battery a.s.o.

Tomorrow i will check it with the Hypertech Controller and hope there´s something stored in the ECU. I will report about. The link you attached is great, hopefully it works on my 94 BRW if the hypertech doesn´t.....

The low oil sensor does not affect anything other than the light on the dash. When the engine quits, the oil pressure light will come on, as well as the SES, and a couple of other lights, because the ignition is on, and the engine is not running.

The fuel is fine, or it would not start.

Things can happen intermittently. Fuel pumps overheat, ignition modules overheat, sensors go out of tolerance, grounds get corroded, and connectors get dirty/corroded. Heat makes some things act strangely, especially after years of use.

Yes, your issue appears to be heat related. You can drive until something gets heat soaked, and acts up, or fails. If the codes do not tell you anything, you need to run it until it quits, and check it at that time. Any time it is running, you will not find the problem. There are some issues that will not throw a code. I am not as familiar with the LT1 cars as I am with the TBI cars, so I am not sure what the 'non code" issues are, but fuel pressure is probably one of them.

"Check the basics first" That was the point I was making, then get into diagnosing deeper. Grounds that aren't completely broken... Loose, corroded, damaged in some way, will give you intermittent problems with any system on a car, heat can, and will contribute to that.

Again, You need to know that the basic systems of your car are in proper working condition when you start diagnosing a problem.

FWIW; Coils, and ICM's are common issues.

Good Luck.

BuickRM wrote:

but remind that my car never has had any troubles with starting till this event this morning. If there´s a problem with ground whereever or with fuel pressure, it would be present now yet always. It ran since May ( when I put it into traffic) without any Problem until this morning when it broke down.

just because the car is in germany,. doesn't mean its become fail safe,.

As they say here in north america,. sh!t happens,. just because it never gave you a problem before ,. doesn't mean a thing,.
things like the fuel pump,. any time anyplace,. 1 second its good,. next its not,.
same for the coil,. the icm,.alternator starter,. etc,. etc,.

All the buicks will give you ecm dtc's,. present and history,.

good luck,.

As an example of parts quitting even if they are not worn excessively, I diagnosed my friends AC Delco fuel pump with less than 20Kmiles as dead. Parts do fail, and usually at the least opportune moment. I personally had a new (off brand) fuel pump die in just 30 days.

Pull your codes, and then you will have a starting point. Without the codes no one can help you, and any comments are speculative at best.

200OZ wrote:

Make sure you have good fuel in the car first off.

I don't think the oil level sensor has any affect on how the car runs. Could be wrong though. That light will turn on when the engine is off, and the key is on.

Quick checks:
- Good charged battery, and tight battery cable connections.
- Engine grounds are tight, and in good condition. Especially the 3 small ground wires under the ignition coil, on the front of the left side cylinder head.
- Ignition coil wire, and the terminal ends are in good condition with no signs of corrosion, or spark leakage.
- Fuel pressure, should be at least in the high 30's up to the high 40's psi. (250 kPa -325 kPa)
- To get codes out of an LT1 Buick Roadmaster you can use the Auto Climate Control.
info on that here in this link:
[You must be registered and logged in to see this link.]

I'd start with this. I second the comments about the coil. I like to keep a spare coil and ICM just in case.

Try now to check the Codes with the A/C-method. Lots of thanks to all ! I hope that it was the pump relay, actually the commonest failure I know from own experiences. If the cat doesn´t start again after it´s broken down and you listen for the pump, you won´t hear its noise. Stupidly I took no care when it broke down that time.
In the Code list, I didn´t find the pump relay, maybe there´s no one at all for it. The Problem with covering such a problem ist that you have to drive around with the car until it breaks down. Even once I take my tools with me, maybe I don´t find the problem away from home and have to call the towing service  second time....
To my information, a car with automatic tranny may not be towed on its axle due to the tranny lubrication, is this the case yet always? So I have to circle around the neighborhood till they are picking me up into the nuthouse

The pump relay does not have a code. You can bypass the car's systems with the pump test connector (single red wire, black connector, beside the AC accumulator). Run a wire from it directly to the positive side of the battery (it will probably make some sparks, but that is OK). If you do not like sparks, make a wire with a clamp on one end, momentary switch in the line, 15 amp circuit breaker, and a spade connector on the other end. If the pump can run, it will, when you make the circuit. Then, if it does not run, and the car will not restart, I would determine that the pump is the issue.

The car can be safely towed for at least 50 miles in neutral.

Have you determined about how far you need to drive for the car to shut off? If you have an estimated distance, drive most of it and end up near your home. Then, you only have to drive around the neighborhood a few times, and your neighbors will only think you are eccentric. You could also put signs in the car windows stating that it is a "test drive".

Since the car will start after sitting for a period of time, you could leave it where it stopped, and go back to it after the appropriate waiting period for it to start again. That would save the cost of towing.

@Fred: just joking, the story with the neighbors.....will get it managed anyway:)

Completely strange: Checked out the relay of the pump today. Supposedly the pre-owner remoted it outside the fuse box with external wires, but on the 85 terminal ( ground of the control circuit) wasn´t a cable at all, no ground. But the pump (and the engine) is running ! I´ve removed the cover of the relais and let my wife start, and the pump and engine is running even though the  contact of the relay doesn´t shut !!!! Once I pull the fuse of the pump, it doesn´t work anymore as it should be. But why runs the pump without the relay closed and did so all the time when I had no troubles obviously without working the relay ? The pump is very good to hear when running at the rear. In the moment, the engine runs everytime I started it, no more troubles since the car broke down 3 days before. But I didn´t trust to drive as yet....will try tomorrow.

There is a second path for the pump voltage through the oil pressure sensor. When the engine has oil pressure, the sensor switch closes and supplies the pump with power. It has a minimum pressure for the switch to close. When your engine is hot, the oil pressure may not be enough to close the switch in the sensor. The sensor is located behind the block, and under the EGR valve. You can R&R it without removing the EGR, but you need the correct socket, and probably a couple extensions with a universal joint. Installing it may be more difficult than removing it. With an extension and socket, you may be able to reach the adapter, just be careful that you do not crossthread the adapter.  Put some sealant on the threads if the sensor does not have any on it when you get it.

Fred,
this means: Until now the engine did start with big oil pressure when cold. Once it gets warm ( as 3 days ago when it broke down) and the oil pressure raised down a bit when idling the fuel pump ( and the engine) has stopped because  the pump relay didn´t work. I never heard from a pump relay which is bypassed by an oil pressure sensor, crazy !

""I never heard from a pump relay which is bypassed by an oil pressure sensor""

This was intended to keep a failing relay or relay driver from shutting down a running car and causing you to go dead in the water in bumper to bumper fast lane traffic.

It may sound crazy, but that's how it works!

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I made a "typo" in the third line from the bottom; it should read: "normally closed" (relay not powered).

Rev Bob wrote:

""I never heard from a pump relay which is bypassed by an oil pressure sensor""

This was intended to keep a failing relay or relay driver from shutting down a running car and causing you to go dead in the water in bumper to bumper fast lane traffic.

Actually, it was intended to supplement the fuel pump relay to enhance the reliability of the system. Failed relays are often first suspected by noticing extended cranking times.

At some point the additional control was unnecessary, so 96's don't have the additional oil pressure switch.

paart wrote:

It may sound crazy, but that's how it works!

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I made a "typo" in the third line from the bottom; it should read: "normally closed" (relay not powered).

Uh no. The TDM sends a signal to the PCM to enable the injectors, fuel pump control is not part of the theft deterrent system.

We have enough marginal tech on here w/o adding to it because people won't refresh their memories before posting, try opening a FSM or do an internet search before stating facts, especially when replying to a request for help and additionally burdened by a different language.

- J

The OP stated that the car is a 94, so it would have the bypass switch in the oil sensor. I was checking a 94 FSM for a friend of mine on Friday, and it showed the bypass switch in the wiring diagram.

""Actually, it was intended to supplement the fuel pump relay to enhance the reliability of the system.""

You said what I said.

JaySS;

Thank-you for pointing out my error. Circuit #465 is powered at PCM connector A7 after 2-3 seconds when the PCM receives low resolution pulses from the OPTI, and not the TDM. The PWM signal from the Theft Deterrent Module only enables the injectors.
It has been awhile since I’ve worked on this, and had remembered it incorrectly, as the results are similar.

I’ve just picked-up a 2003 Buick Century to drive for a couple months while I do some upholstery and maintenance work on my wagon. Does anyone know off-hand, if the theft deterrent and fuel delivery system is essentially the same as my ’95 Roadmaster?

Guys,
completly new situation: It´s not the fuel pump. Today I adjusted the front wheel toe at my brother-in-laws yard 5 miles away. The car ran without troubles to him. Then I worked on the yard about  1 1/2 hours in scorching heat. When I wanted to leave him the car ran 200 meters to the next crossing up the hill and then broke down. I cranked again and the engine started just shortly and broke down again and didn´t start any more. I took pretty care to listen to the noise of the fuel pump, it definitly worked without any doubts. It´s not a problem of the pump. I let the car run down reverse the hill without the engine to the yard. Tried to start again - didn´t run. Phoned my wife to pick me up and went to the brother-i-l  to wait till she´s coming. After 20 min she came, I started the car and it ran without troubles home. My brother in law said that once I started first time to leave him, the engine smells of fuel. So I think it´s too rich and rather no problem of steam bubbles. Some weeks before I replaced the water temp. sensor because the terminals were broken. This part should be ok so far.

Unfortunatly, the guys of hypertech told me today that my power programmer isn´t able at all to read DTCs. So I have less possibilities to analyse my problems.....It´s just present when the car is hot for a while. Does someone know if it´s possible to blink the DTCs?

The LT1 cars do not "blink" the codes. You have to pull them with the proper tool.

If it is only present when hot, it is a heat soak problem. The computer will not necessarily recognize that and throw a code.

Make a list of what you did swap out, and what you did not.

A rich mixture can be an O2 sensor (2?), timing (ignition module), fuel pressure regulator, coil wire, coil, temperature sensor, and probably a couple more items. I did not include the plugs, stuck injector, or ignition wires because it would be less likely those than the other items that are common to all or most cylinders.

BuickRM wrote:

. Does someone know if it´s possible to blink the DTCs?

I would think that you may have a temp sensor problem still,.or possibly a leaking injector,.

AS was pointed out to you before,. you can retrieve trouble codes thru your hvac screen.
it will give you current codes and historic codes too,.

The instructions to do this are here:
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The codes that should be of greatest concern are in the (-00) or (-01) group.

@paart
Thanks, I tried it already, but I`m not yet that familiar with it. I would like to delete the irrelevant trouble codes before to give a new chance to put new ones after the engine broke down and then  the DTC is defined new.  How can I delete the storage?

To my experience, there are a lot of stored codes which a irrelevant and just confusion, because they are put due to normal engine functions. Those I would like to delete at first. How can this be done?

Remove the computer fuse for at least one minute, and the codes will be erased.

Guys,

Now I`ve fixed the Problem. As I told you before, I replaced the water temp. sensor because the terminals were broken. The pre-owner replaced the water pump, I guess he damaged the sensor at this opportunity...Three weeks ago, I replaced my water cooler and I discovered the damaged sensor, ordered a new one and replaced it together with the cooler.

Yesterday, I checked the DTCs via A/C dispaly ( lot thanks Fred and all others !!) and found Code 15 and 43. 15 is water temp. sensor. Because I replaced it, it´s a bare possibility that it´s broken again, so I was going to check the terminal. Once I pulled the terminal connector, I was pretty sure having found the problem: The terminals inside were visually heavily  corroded !! It might be happened when the pre owner changed the water pump and water was running over the connector, I don´t know...Anyway, I picked out the rust and treated it tenderly with antirust solvent. Then ( unfortunately not bevor) I checked the voltage when ingnition was on, it has to be 5 Volts, it was exactly the figure my tester showed me.

The voltage drop at the sensor caused the injection thinking it´s a cold start and the engine was overflowed with fuel when hot. I`ve tested the car very extended, run it hot , stopped it and let it heat up in the sun with various times to restart. As well I went for 30 miles and tried again. It´s completely ok, no issues at all, car works perfect. Why did the car work during the past without troubles, but with the damaged sensor? Since 2 weeks, in Germany it´s hot very similar to Floridas or Californias conditions. The time before, it was at least 10 or 15 degrees (please remind, I mean Celsius ;-)) lower. Then the car startet despite of the rich fuelling. Once the car is running on the road, the Lambda Control Loop tries to adjuste the fuelling to Lambda 1, what seemed to be possible, at least approximately. During starting, the Control Loop of the Lambda isn`t closed, the starting procedure takes the injection times which are fixed stored in the PCM, and these are calculated with the voltage signal from the water temp. sensor which was wrong. The Lambda Control loop has no influence on the starting procedure. Due to this, there were this starting issues which are heavily enhanced once it gets hotter.

The Code 43 was showed as well, this is a knock sensor, I don´t know if the code is stored for a longer time or it came up with my current troubles. The car doesn´t ping, particulary it´s driven very rarely with wide open throttle and good fuel. I will delete the codes as you told me, go for a while and recheck it. I also found out that there´s no fault lamp at my cars display, at least it´s not working, but I don´t know the cut-off point when it should be present. I think it might have been burnd due to the massive breakdown the engine has had. I will have a look once I get the time.

Anyway, again lots of thanks for all who adviced me that well !

Udo

The knock code may be a symptom of the temp sensor issue.

One of the reasons it ran for a period of time before quitting, is that the computer does not go into closed loop for about 5 minutes, or until the engine temp (sensor) sends a minimum temperature reading. After the time delay, the computer looks for the sensor input, and adjust the mixture for the current reading. If it gets a reading that is outside the parameters it is supposed to be, it can shut down the engine.

It's great that you fixed it,.I thought you might still have a problem there,.

You can buy just a new connector with two new short lengths of wire to repair this kind of problem,.

Now find a nice set of T84 headlights for me from your local auto recycling yard will you,.?

@Fred: I agree, maybe thats the reason for overflowing the engine...I will replace the connector and  will find one in Germany as well. In the moment, ist works perfect.
@Phantom 309: What are T 84 headlights? Please keep in mind that on our scrapyards american cars are very rare ( if it is one) You won´t find them supposedly. Did you look on eBay?

The rich mixture is not from the knock sensor. The knock sensor will cause the timing to retard to stop the knock. I would not worry about getting a connector or knock sensor unless it throws a code again.