Fuel pump starts running with ignition on 82SC

[jtfreels]

I just put the engine back in after putting in a new clutch. Also replaced the fuel filter.
First test was just to turn the ignition to on position, first surprise the fuel pump starts running and I'm guessing it's the frequency valve buzzing.
Take out the fuel pump relay and it stops (of course) put in a new relay and fuel pump starts again.
The air flow sensor wire is connected, don't see any thing else loose.

Any help/suggestions are welcome.

Thanks

Jay

[john walker's workshop]

if the green plug for the sensor plate contact is not connected, that's what happens. the blue one goes to the cold start valve. don't mix them up.

[rsscotty]

I have seen this before ..the connector for the air flow meter was interchanged with the one going to the cold start valve. Any chance you had both off?

[boyt911sc]

Originally Posted by jtfreels

I just put the engine back in after putting in a new clutch. Also replaced the fuel filter.
First test was just to turn the ignition to on position, first surprise the fuel pump starts running and I'm guessing it's the frequency valve buzzing.
Take out the fuel pump relay and it stops (of course) put in a new relay and fuel pump starts again.
The air flow sensor wire is connected, don't see any thing else loose.

Any help/suggestions are welcome.

Thanks

Jay

Jay,

Pull out the red FP relay and test terminal #85 of the FP relay socket. Ignition switch @ OFF, connect a test light/lamp to the battery (+) terminal and use the probe to locate for ground at #85. I would bet my money it is OPEN (no ground). This is the reason why your FP is running when the ignition switch is @ ON position. Even if you have the right plug (green) installed at the right place but not grounded, FP will run when Ign. SW @ Run/On position. Keep us posted.

Tony

[jtfreels]

Both plugs are on I never took them off. But Tony uses the word ground and I can't remember putting the transmission ground strap on could that be it?

Thanks guys, I guess I'll be jacking it up again.

Jay

[boyt911sc]

Originally Posted by jtfreels

Both plugs are on I never took them off. But Tony uses the word ground and I can't remember putting the transmission ground strap on could that be it?

Thanks guys, I guess I'll be jacking it up again.

Jay

Jay,

The operation of the FP relies on the FP relay and its wiring connections. With the ignition switch @ ON/Run position, the FP is not designed to run. However, there are things that could make the FP to run like what you are observing like:
a). Defective FP relay
b). Terminal #85 has no ground contact. What could have caused terminal #85 to lose ground contact?
-----AF switch defective, misaligned, etc.
-----wiring anomaly, loose connection, cut wire, etc.
-----poor contact

The transmission ground strap has nothing to do with this test. This is a one-minute diagnostic test and avoid guessing!!!! Is terminal #85 grounded or not? Keep us posted.

Tony

[jtfreels]

Using a volt meter connected red lead to positive battery terminal and black to 85 on FP relay socket volt meter shows 0.02 volts.

Jay

[timmy2]

Jay, switch your meter over to OHMS and connect one probe to relay socket 85 and touch the other probe to the negative terminal ground.
What does it read?

[jtfreels]

Shows 1 what this volt meter shows when the leads aren't touching any thing

[boyt911sc]

Jay,

Set the meter to 'continuity test'. Place one tip of the meter to a known ground source and the other to terminal #85 (fuel pump relay socket). Or use a test light (12V). And determine if #85 is grounded!!!!! It would take a couple of seconds to do this test. It is either grounded or not. At normal condition (setting) terminal #85 should be grounded. Leave the ignition switch alone it does play a role in testing the culprit. Keep us posted.

Tony

[jtfreels]

This cheap volt meter doesn't have a continuity tester, but.... With the key off ( it's in my pocket) I'm getting 12volts on
87
87a
86
30

According to another thread fuel pump relay

It should be
87...........no power
87a.........no power
86...........no power (87a 86 are bridged)
85...........no power (should be grounded at this point)
30...........no power (has ground contact?)
So something not right there

And then with the switch on
87 12v
87a 0
86 0
85
30 12v
Which should be like
87............no power
87a..........has power
86...........has power
85...........no power, presence of ground contact
30...........no power, presence of ground contact

So I've done something wrong but haven't found it yet.

Jay

[boyt911sc]

Originally Posted by jtfreels

This cheap volt meter doesn't have a continuity tester, but.... With the key off ( it's in my pocket) I'm getting 12volts on
87
87a
86
30

According to another thread fuel pump relay

It should be
87...........no power
87a.........no power
86...........no power (87a 86 are bridged)
85...........no power (should be grounded at this point)
30...........no power (has ground contact?)
So something not right there

And then with the switch on
87 12v
87a 0
86 0
85
30 12v
Which should be like
87............no power
87a..........has power
86...........has power
85...........no power, presence of ground contact
30...........no power, presence of ground contact

So I've done something wrong but haven't found it yet.

Jay

Jay,

Are you doing the test with the FP relay completely out of the socket? Your ignition switch is suspect at this point. Power should NOT be present at the same time for terminals #87 & 87a at any given point. Even with a bad FP relay, I could not imagine it will display the results you just obtained.

With the key off, there should be no presence or 12 volts in the circuit. For this to happen, you have a stray 12-volts in your ignition switch. Have you touched the ignition switch wiring recently? BTW, those data you posted looks familiar to me.

Tony

[jtfreels]

Yep Tony those are your words, copied and pasted

I'm starting to suspect the ignition my self.

The short story with the car, started to have shifting problems, so I dropped the engine, replaced the clutch and put the engine back in.
Did the minimum required to drop the engine (as far as things to disconnect, so really only in the engine compartment).

this did take me a couple of months due to personal issues where I couldn't work on it.

But I've not "messed" with anything really regarding electrical, which is one reason I'm puzzled so on this one.

Jay

[GothingNC]

Does it still happen if you swap the red relay with on of the black ones?

I had the issue of the fuel pump running before the engine cranked over it it turned out to be a bad relay.

[jtfreels]

Originally Posted by GothingNC

Does it still happen if you swap the red relay with on of the black ones?

I had the issue of the fuel pump running before the engine cranked over it it turned out to be a bad relay.

Yes I've tried multiple relays, seems not to be a relay problem, but electrical to the relay.

Jay

[jtfreels]

Still looking for help. What in heavens name would cause me to get (with the key OFF) 12volts on
87
87a
86
30
of the fuel pump relay
I'm putting one probe of the lot meter on each socket and one on the poistive of he battery.

And the wit the key ON I get
87 12v
87a 0v
86 0v
30 12v

[boyt911sc]

Originally Posted by jtfreels

Still looking for help. What in heavens name would cause me to get (with the key OFF) 12volts on
87
87a
86
30
of the fuel pump relay
I'm putting one probe of the lot meter on each socket and one on the poistive of he battery.

And the wit the key ON I get
87 12v
87a 0v
86 0v
30 12v

Jay,

I could be wrong but I find a flaw in your test procedure. With the key out of the ignition switch could you do these tests for us? Use a 12-volt test light (less than $5 for a set of 3 from HF). Please believe me, life would be easier if you use a simple 12 volt test for these diagnostic tests. I'll number the tests as:

1. With a test light, confirm that the test light is functional by testing it using the car battery.
2. Now, that you have confirmed that the TL is good, test terminal #85 (fuel pump relay socket) with FP relay pulled out. Hook up the alligator clip of the test light to the (+) terminal of the battery and check terminal #85 using the probe.
Normally it is grounded and expect to see the TL to light up.
3. After confirming the presence of ground contact @terminal #85 from test #2, use terminal #85 as your next ground point and test the following:
#85 and 87..........?
#85 and 87a........?
#85 and 86..........?
#85 and 30..........?

Secure the alligator clip (TL) to terminal #85 by using a pin or nail and test again using the (+) terminal. Once the TL lites up you are ready to proceed to the investigation. Place the probe (TL) to terminal #87; terminal #87a; terminal #86 and finally terminal #30.

I'm interested about the results for test #3 using a TL and nothing else. I'm no electrical whiz but I could sketch the electrical diagram in my sleep (figure of speech) and been fooling around with circuits #105 & #106 as a past time. Keep us posted. Thanks.

Tony

[jtfreels]

Tony, thanks for responding I've been out of pocket for a bit and at work now.
I've got the "unpowered" simple test light now. I'll redo my test (again) with it an publish the results.

So that I'm clear
for step 3 put the test light between 85 and 87 and see if it lights up? and repeat for the following pairs? (Just to make sure because that is NOT what I've done in the past tests; so I've added to my own confusion)

Thanks

Jay

[j911brick]

bad ignition switch?

[boyt911sc]

Originally Posted by jtfreels

Tony, thanks for responding I've been out of pocket for a bit and at work now.
I've got the "unpowered" simple test light now. I'll redo my test (again) with it an publish the results.

So that I'm clear
for step 3 put the test light between 85 and 87 and see if it lights up? and repeat for the following pairs? (Just to make sure because that is NOT what I've done in the past tests; so I've added to my own confusion)

Thanks

Jay

Jay,

Do this test with ignition switch OFF and another test with ignition switch ON. Keep us posted. Thanks.

Tony