Change fuel pump 1990 reatta - 1990 Buick Reatta

Question edited for clarity.

They all work to a similar theme. The Buick LeSabre will be close enough.

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1990 Buick Reatta Door Lock Actuator - VDO AC89312

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Don't understand ......the fuel metering is done by the ECM. You must drop the gas tank to get to the fuel pump.

Normally if it shuts off within 5 seconds or less, it can be traced back to a faulty anti theft security system. GM put this system called Vats in its vehicles since 1982. It tends to wear out and cause "no start" situations for many car owners. This might be your problem and due to the year of your car, i would lean strongly toward this. The average life of a Vats system is 6-10 years. You're a little past that. Ive got a link for you that explains symptoms and how this system works. It also has 2 possible solutions for your Reatta if this ends up being the problem. Good luck hope you figure it out. http://vatspasslockpasskeysecurityhelp.yolasite.com/

Check fuel pressure with a gage. The TPS has to be set correctly to work right. May be a map sensor vacuum problem or crank sensor for a 1990 buick. What do you have as the header is confusing.

Crank sensor.

sold as a unit only
check with a buick parts deparment to comfirm if wanted

1990 Buick REATTA Recall ID from NHTSA: 90V164000 Auto Recall Date: 09/06/1990
Vehicle Component: POWER TRAIN:AUTOMATIC TRANSMISSION:LEVER AND LINKAGE:FLOOR SHIFT
Estimated Vehicles Affected: 63964
1990 BUICK REATTA Defect Summary:
TRANSAXLE SHIFT CONTROL CABLE MAY DISENGAGE FROM THE FROM THE FLOOR SHIFT CONTROL WITH LOSS OF GEAR INDICATOR REFERENCE AND SHIFT SELECTOR OPERATION.
Defect Consequence:
DRIVER WOULD NOT BE ABLE TO DETERMINE ACTUAL GEARPOSITION THE TRANSAXLE IS IN, WHICH COULD RESULT IN UNEXPECTED VEHICLE MOVEMENTAND AN ACCIDENT WITHOUT PRIOR WARNING.
Remedy:
INSTALL A TRANSAXLE SHIFT CONTROL CABLE RETAINING CLIP TO PREVENT CABLE DISENGAGEMENT.
Notes: GENERAL MOTORS CORP., 1990 Buick REATTA Recall ID from NHTSA: 91V158000 Auto Recall Date: 09/13/1991
Vehicle Component: SERVICE BRAKES, HYDRAULIC:SWITCHES:BRAKE WARNING
Estimated Vehicles Affected: 18904
1990 BUICK REATTA Defect Summary:
BRAKE INDICATOR LIGHT MAY NOT LIGHT WHEN IGNITION IS IN THE "ON" POSITION, THE PARKING BRAKE IS APPLIED, AND THE SHIFT SELECTOR IS IN THE PARK OR NEUTRAL GEAR RANGE.
Defect Consequence:
VEHICLES WOULD NOT MEET THE REQUIREMENTS OF FMVSS 101AND 105.
Remedy:
REPLACE THE PROM IN THE BODY COMPUTER MODULE TO PREVENT THIS CONDITION FROM OCCURRING.
Notes: GENERAL MOTORS CORP., 1990 Buick REATTA Recall ID from NHTSA: 90V031000 Auto Recall Date: 02/12/1990
Vehicle Component: AIR BAGS:FRONTAL:SENSOR/CONTROL MODULE
Estimated Vehicles Affected: 857
1990 BUICK REATTA Defect Summary:
THE FORWARD SENSOR FOR THE AIR BAG MAY HAVE BEEN INCORRECTLY CONSTRUCTED WITH PART OF THE WIRING HARNESS TO THE SENSOR REVERSED.
Defect Consequence:
THE REVERSAL OF THE WIRES COULD CAUSE DELAY IN THE DEPLOYMENT OF THE AIR BAG AND INCREASE THE SEVERITY OF THE OF INJURY TO AN UNBELTED DRIVER IN AN ACCIDENT.
Remedy:
REPLACE FORWARD DISCRIMINATING SENSOR AS NECESSARY.
Notes: GENERAL MOTORS CORP.

sounds like your fuel pump is going out. One thought might be that the fuel filter is causing enough resistance to over heat the pump. I would check the fule pressure to determine a free flow of fuel.

Per your description, I would suspect a fuel pump issue. When the fuel pump is running the pump impeller heats up. On an older pump the impeller can begin to seize up and momentarily stops and starts. Some times it just stops and has to cool down for a couple of minutes, then is ok for a while.
To test this theory, when the engine stalls and stops, your mechanic can use a rubber mallet and hit the bottom of the gas tank, this will free the pump impeller and the car will start again.
Or, have him install a fuel pressure gauge and go for a drive. If the pressure begins to fluctuate and drop, you know the pump is causing the issue.
Good luck, let me know.
Regards,