Fuel pump?

[jseremba]

I own a 1984 4 plus 3 Corvette. It is stock except I ported the intake. It was running well and sometimes it seemed to hesitate. Today I was driving it and it hesitated and stalled. I called a tow but got home with some clutch riding and a little luck. Oh I disconnected the EGR.
I replaced the fuel pump in February. Changed the fuel filter in May. I think the fuel pump may be the problem. How do I test it? and I was wondering about the regulators. Can I put a single regulator on the manifold and remove the ones from the TBI's?

Thank you for the help.

 

[Hib Halverson]

After you ported the intake did you change the calibration to one intended to work with a ported intake manifold?

Also, depending on how you ported the manifold you may have actually degraded the quality of the airflow in the runners and that can cause hesitation.

But, it is true that a fuel pressure problem can also cause drivability quirks.

Have you run the fuel pressure tests listed in the factory service manual?

 

[jseremba]

After you ported the intake did you change the calibration to one intended to work with a ported intake manifold?

Also, depending on how you ported the manifold you may have actually degraded the quality of the airflow in the runners and that can cause hesitation.

But, it is true that a fuel pressure problem can also cause drivability quirks.

Have you run the fuel pressure tests listed in the factory service manual?

I went to the shop manual and did not find a fuel pump test. I do not know how to change the calibration
As for the porting degrading the air flow I do not think that is the case. The car always had a little hesitation and only had 16" of vacuum at idle. Now I have 20" of vacuum at idle. And a very steady idle

 

[jseremba]

I went to the shop manual and did not find a fuel pump test. I do not know how to change the calibration
As for the porting degrading the air flow I do not think that is the case. The car always had a little hesitation and only had 16" of vacuum at idle. Now I have 20" of vacuum at idle. And a very steady idle

I looked at the ECM codes. I got a 15 coolant temperature. My radiator fan keeps blowing the 3 amp fuse. I changed the relay, motor. I thought that when I grounded the switch wire the fan would run but it does not. I tried to trace the wires. The blue switch wire, which has power until the fan switch tries to turn on the fan, goes from the connector into a block that goes into the dash. If the switch wire were grounded the fan would run all the time, correct. In short I do not know where to look. Keep in mind that up until a couple of days ago it was running fine. what changed?
thank you

 

[hal1phx]

I own a 1984 4 plus 3 Corvette. It is stock except I ported the intake. It was running well and sometimes it seemed to hesitate. Today I was driving it and it hesitated and stalled. I called a tow but got home with some clutch riding and a little luck. Oh I disconnected the EGR.
I replaced the fuel pump in February. Changed the fuel filter in May. I think the fuel pump may be the problem. How do I test it? and I was wondering about the regulators. Can I put a single regulator on the manifold and remove the ones from the TBI's?

Thank you for the help.

I would certainly want to check the fuel pressure .... best check is between the TBs ... should carry 14-15# of pressure with your set up .... If the pump's not producing that amount for you, you can go to an 85 pump, which will supply improved pressure.
The regulator in the TBs should take care of you ...... IMO adding an external would be a waste of time and money .....
Hope this helps ....

 

[jseremba]

fuel pump

I would certainly want to check the fuel pressure .... best check is between the TBs ... should carry 14-15# of pressure with your set up .... If the pump's not producing that amount for you, you can go to an 85 pump, which will supply improved pressure.
The regulator in the TBs should take care of you ...... IMO adding an external would be a waste of time and money .....
Hope this helps ....

So I solved the problem. What I did was put a plunger switch from battery to the fuel pump. So now I turn the key and press the switch. The car starts instantly. I di this because I had used my ohm meter and determined that my grounds were good and that there is no shorts. Yet the pump does not power up when I depress the key or when I run power to the G terminal of the ALDL. the car runs great.