1989 Buick Riviera



August, 31, 2009 AT 11:05 PM

Electrical problem
1989 Buick Riviera 6 cyl Front Wheel Drive Automatic 225000 miles

good spark, fuel in line to injectors -- sprayed fuel into intake -- engine fires -- no fuel to cylinders via injectors -- it has been suggested the security system is preventing injector operation -- also, the computer displays low oil pressure while engine is off & the diagnostic message indicates vehicle & engine problem -- prior to replacing the oil pressure sending unit " electrical problem" displayed on the dash display -- after replacing the oil pressure sending unit there was no note of " electfrical problem" -- a while back the fuel pump stopped working -- had to wire it direct to the battery with a switch in order for it to operate 973-202-4515 ASAP please

10 Answers



September, 1, 2009 AT 2:32 AM

Check the fuel pump relay in the under hood fuse box. Swap it with one of the other relays, preferably not an important one! Healight relay or a/c. Check all fuses marked IGN or ECM.



September, 1, 2009 AT 8:04 AM

Merlin2021 -- I want a refund of my $20 -- your response to the question does not answere the problem -- IF YOU READ THE OPENING STATEMENT -- I HAVE FUEL TO THE ENGINE VIA THE FUEL PUMP BE WIRED DIRECT -- THE -- THE INJECTORS ARE NOT ACTIVATING



September, 2, 2009 AT 3:12 PM

The C(3)I system uses waste spark method of spark distribution. In this type of ignition system, ignition module triggers No. 1 and 4 coil, resulting in both No. 1 and 4 spark plugs firing simultaneously. The No. 1 cylinder is on compression stroke at the same time that No. 4 is on exhaust stroke, resulting in a lower energy requirement to fire No. 4 spark plug. This leaves the remaining high voltage to fire No. 1 spark plug. The sequential fuel injection type of fuel delivery system utilizes 6 separate injector " driver" circuits to activate 6 fuel injectors. While cranking, ECM activates all 6 injector " driver" circuits simultaneously. After a calibrated engine RPM is reached, and a good camshaft signal has been received by ECM, the injection mode of operation is changed to sequential (sprayed in spark plug firing order). Fig. 15: Chart A-3, Wiring Diagram Engine Cranks But Will Not Run (1 of 4) 1. This test verifies that " SES" light operation, TPS and coolant sensor signals are normal. A blinking injector test light verifies that ECM is monitoring C(3)I reference signal and attempting to pulse injectors. 2. The crank sensor has been verified as functioning properly. Performing a fuel pressure test will differentiate between fuel related or ignition system problem. 3. By testing for spark on plug leads 1, 3 and 5, each ignition coil's ability to produce at least 25,000 volts is verified. If engine starts, runs for several seconds and dies repeatedly, consider this to be no spark at all. 4. Checking faulty coil's control circuit using a test light, will determine whether coil is faulty, or module's internal driver for that coil is at fault. 5. This test checks for battery voltage at circuit No. 639. If voltage was present, " light off" test result was caused by no activation pulse reaching injector connector from ECM. 6. If fuse was blown, check circuit No. 839, which includes fuel pump relay, fuel pump and wiring, to determine cause of high current flow. 7. Test light to 12 volts simulates a reference signal to ECM. This results in an injector test light flash with each contact of test light probe to terminal " D". It may take up to 3 probe contacts to flash test light. If test light flashes, circuit No. 430, ECM and injector driver circuits are functioning properly. 8. If crank sensor signal circuit terminal " A" is momentarily jumpered to ground circuit terminal " C", and engine is cranked without turning ignition off, the response should be an injector test light flash. The ignition module will then transmit fuel control signal to ECM while cranking. Allowing generation of reference signal to ECM terminal " BD8", and ECM to activate injector driver circuit. 9. This test verifies proper sync-signal circuit voltage of 9-12 volts, and a proper ground from C (3)I module to terminal " C" of sensor connector. 10. Determines if reason for incorrect voltage reading was due to fault in circuit No. 645 or faulty C(3)I module. 11. Jumping crank sensor harness terminals " A" and " C" together, simulates a sync signal to ignition module. By jumpering crank sensor harness terminals " B" and " C" together, a crank signal is simulated. This signal will then cause ECM to energize fuel pump relay for 2 seconds (it should click on and off) and injectors should be heard clicking on and off. 12. Verifies a proper crank signal circuit voltage of 9-12 volts and a good ground from ignition module to terminal " C" of sensor connector. NOTE: Test numbers refer to test numbers on diagnostic chart. 13. Determines if reason for incorrect voltage reading was due to a fault in circuit No. 643, an open in circuit No. 645, or a faulty ignition module. BTW check email, charts sent in PDF format. Let us know how you make out. I don't theink it's security problem unless the light never stops blinking?



September, 3, 2009 AT 7:37 PM

Ok merlion 2021 -- thank you for the PDF info -- willl print out -- as well as digest the great info in the last reply

being that the security system does not appear to be the culprit let me give you another run down on the progression of failures over the last year just to see if perhaps before we go any further there could be a deterioration in the ecm that up till now has allowed the car to function but perhaps has reached a point where it is shutting down the injectors

the car has the touch screen computer

the dash has been noting service engine for years -- a diagnostic indicated an engine control and a problem in 2nd gear of the trans

last year the wipers began to act strange - can't recall exactly the action -- but I pulled the #12 wiper fuse -- the wipers resumed normal operation -- with out the fuse! So -- the fuse has been out

six months back the car would not start -- no fuel -- fuse & relay ok -- cut a hole in the floor and removed the pump -- tested good -- cut the wire to the pump and wired it direct to the battery with on/off switch
-- it has worked just fine

dash noted electrical problem

recently the screen has come up reading low oil pressure -- yet the reservoir is always at capacity & oil pressure is normal but the gage had been indicating a pressure fluctuation -- replaced the oil sending unit -- the same message concerning oil pressure comes on the screen but the dash no longer says electrical problem or service engine soon

I replaced the trunk courtesy light bulb -- #5 fuse (courtesy lights) blew -- this has happened previously, however, this time the light would not go out when the lid was closed (next day dead battery) -- so I removed the socket -- all interior lights are fine

the diagnostic message now notes car & engine failure -- but climate and. Are fine

so -- with all that said -- could there be a progression of failures in the ecm -- wipers, fuel pump, oil pressure note, etc that I have been able to circumvent till it has reached the control of the injectors?

Or could the security system be acting normal yet blocking the injectors?

I may try replacing the fuel pressure unit just to rule it out if you think it is a still a possibility -- but with all the other crazy things I have my doubts



September, 4, 2009 AT 2:50 AM

GM also has a tech bulliten out on thier electrical connectors, making sure they are fully toghether, and there are no bent or pushed out pins, also if wipers work with no fuse, the wiper relay wiring should be checked for a short. Same for the trunk light, check wires and connectors, also clean all grounds you can find, especially the ECM!



September, 4, 2009 AT 2:22 PM

Yes -- all relays at fuse area & in relay box under hood checked -- although the injector fuel pressure control did not have leakage past the diaphram I replaced it just to make certain there was no fuel pressure issue --

still no start



September, 5, 2009 AT 7:04 AM

Do the injector pulse? use that noid light as instructed in the PDF I sent? If no pulse, some GM's diable the statrer a a security measure some disable the fuel. What does the security light do when you get in the car? Turn key to "on"? Crank for 2-3 Secs?
Cam sensor and crank sensor signals present to ECM?
And does it have good spark? If it's fuel related and you had an oil pressure issue, there is a saftey built into the ECM to not allow the engine to run, by cutting off fuel, is this a CFI or SEFI(port) injected model? Did you remove the power distribution box and inspect wiring from underneath?;feature=related
Watch this video by Jake. And this one.



September, 5, 2009 AT 8:33 AM

OK -- it will be a day before I can get to the last info -- will get back to you asap



September, 5, 2009 AT 8:45 AM

Will be lookin out!



September, 12, 2009 AT 7:09 AM

From my email inbox: Due to frequent loading & unloading of the car which often takes time, I remove the trunk courtesy light bulb and block the door switches to save battery. When pushing the bulb back into the socket I usually blow a fuse. The blown fuse takes out the interior lights as well. Schedule never permitted investigation of the problem and a fuse was a quick access and fix.

Then came the moment when I had no spare fuse.

The fuse block is labeled for circuit application of each fuse. Well. There is another fuse block, not specked in the manual etc with no identity of the fuses.

Normally, this second block is not visible. The central fuse block is covered by a removable access door in the console side panel. This second block is behind the panel with no access.

However, due to " interior modification", this second block was fully exposed and I had long forgotten the territory for primary fuse block access.

That being the case. In a mad rush to get going last winter after popping a fuse. I reasoned this block, with such a variety of fuses and no significant markings was a courtesy spare fuse supply of which has been supplied by manufacturers at times. It was greater than I had ever seen -- but then again there was a wide range of fuse values in the main block. Clearly I was operating from another planet at the time.

The fuse transfer took place with no side affects to vehicle operation and my assumption there was a set of spares provided was justified.

Later on, another " trans fusion" took place. Well, the radio had a habit of blipping off and then back on -- nothing new -- just figured it had the big blip and was finally gone as the fuse in the main block for the radio was OK.

Yet another " trans fusion" to the rescue! By this time one would think by now I would not care about the trunk courtesy light working.

Riv will not start. There was no time to investigate and it was winter.

Spring -- by this time who remembers the critical sequence of lights out and fuse transfer.

Investigation revealed no fuel supply. I did have a fuel pump suddenly fail in a Suburban. Stopped at the store -- came out -- nothing. So, after preliminaries I determined the fuel pump is history. Upon removal I do a quick check to verify. The pump works by direct battery connection -- so there must be a circuit problem of which there is no time to check. I become the controller of fuel supply.

The wipers suddenly took on a operation sequence without request. Yanked the fuse and normal operation resumed - so the fuse was not replaced as there were no side effects for vehicle operation.

Recently an excursion required removal of the trunk lid for cargo space. Reassembly. Yes, . &Quot; trans fusion"!

The car was not used for several days following the latest fuse replacement.


Getting ready to head out -- the computer screen is showing engine & vehicle system failure and stating low oil pressure -- the dash not only indicates check engine but now messages there is an electrical failure.

I had fuel and great fire. Ether to the air intake gave immediate starting results. Why are the injectors not stoking the fire! And where did all of the problems arise from? If the security system, oil pressure, fuel pressure regulator fail or the ECM has issues the injectors will not spit a bit of fuel.

All checked out. Then I looked at the fuse block with 3 of 8 fuses left.

FUSE ROBBER has paid several fines, been humiliated, and replaced all stolen fuses -- the trunk courtesy fixture has been EXTRACTED.

Except for the check engine light being on for " engine controls", which has been on for years -- the Riv is rollin'


2carpros have been great with assistance in troubleshooting and supplying data for tracing the system at hand.
All is good? Take care!

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