89 astro stalls but resterts right away

[keith12]

Just started this, runs good but with no warning shuts of.
Doesnt matter if at highway speeds or at idle. Will restart right away.

Had a similar problem a couple of years ago. Did a jiggle test and found the connector to the oil pressure switch was the problem. So that was the first place I checked, to no avail.

Any ideas as to where to start.
fuel filter?
fuel pressure?
fuel regulator?
oil pressure switch itself?
o/2 sensor?
map?

ecm hasnt thrown any codes.

[CD Smalley]

check out your fuel pressure relay...

[Blue Bowtie]

Oil pressure switch?

No. A common misconception is that the auxilliary oil pressure switch is a "safety" device to kill fuel pump power in the event of oil pressure loss. That is NOT how GM vehicles are wired. The oil pressure switch is simply a parallel, redundant power path for fuel pump power in the event the relay circuit fails. A quick look at the circuit makes that obvious:



Since the problem is transitory, it's going to be difficult to find unless you just happen to be monitoring fuel pressure and ignition power when it occurs. isolating the cause to either fuel or ignition is going to be important. HEI switching modules have been known to act similarly, as well as the pickup coil/reluctor in the distributor base. Typically, however, they require a brief period of cooling before they will operate again, so I'd agree with CD that the fuel system is more suspect by your symptoms.

[drew300]

How about electrics?
I had a bad ignition switch do this type of problem

[keith12]

I went down and bought a regulator rebuild kit.
I'll get that installed and let you know what happens