Check out this video for help with testing the FPR, the part where he tests it starts at 1:50

Thanks for posting the video. I had pulled the vacuum line, but didn't wait nearly as long as in the video. There was no strong smell of gas though.

I did take the car for a drive this afternoon and the SES light came on. And off. And on. And off. And on ... The closest thing to a pattern is that it seems to be on solid at highway speeds, but in town, or on the hilly road I was on, it was on and off.

Of course, I don't own an OBDI scanner and the local parts houses don't either. I vaguely remember a table of blink codes for this thing. I'm off to search for it.

Thanks again!
Jim

https://www.gmforum.com/specificatio...cks-**-278820/

Just let it idle for several minutes without the vacuum hose attached to the Fuel Pressure Regulator. No visible leaks, no smell of gas at the vacuum hose.

Just read the blink codes.

34 and 41

34 is Mass Air Flow reporting low air flow

41 is Camshaft Sensor not functioning properly

Camshaft sensor was replaced last year and has around 1000 miles on it.
Mass Air Flow sensor is new (reman) as of yesterday.

What is the reset/relearn procedure for this computer? I'm wanting to guess that the MAF issue is due to the computer not yet having learned there is a new MAF Sensor.

The car is currently doing EXACTLY what it did several years back when the camshaft sensor needed to be replaced - that is, it cranks for several seconds and then will start. Sometimes you have to turn the key a second or third time - but it will start. In fact, when this all started last year, I thought "Oh, it needs a new camshaft sensor."

Thanks for all the responses. I do appreciate it.

Jim

on obd1 you can remove the battery cable to reset the computer. make sure you check those sensors for loose wires or crud first

Codes reset.

Sensor wires look clean and tight and as if there are no problems.

Time for a test drive. How long does the re-learn take? Is it timed by miles driven or start cycles or just time?

Thanks again,
Jim

there is no set time the learned values start coming back as you drive it. as far as maf and cam sensor go should be after the engine warms up and goes into closed loop you will know if the code comes back

Returned from the latest test drive ...

SES light is back on with code 41 - cam sensor. It came on after about 15 miles over the mountain.

MAF sensor code is gone!

We've owned this car for the last 100,000 miles and this is the second or third Camshaft sensor that we've put on it. Is that normal?

Would there be any rhyme or reason to needing a second camshaft sensor less than 18 months and 1000 miles after the last one?

What normally causes them to fail?

Thanks again,
Jim

I would always recommend that you use the Delco replacement part for sensors.
Sometimes it is not the sensor but the magnet is MIA.. (missing in action)
Luckily I have not had to replace mine (touch wood) what is everyone using to attach the magnets with JB weld 1 hour cure or .....?

More than likely the magnet is gone from the upper timing sprocket. With that many miles its probably due for a timing chain set.