fuel pump problems

[ernbuild]

It would appear I have fuel pump problems with the ZR1.When the car is hot and am driving on winding roads , twice now it has blown the fuse at the dash. This causes it to just stop dead. Almost had an accident today because of it.
That being said let the dammed thing cool down replace the fuse and your back on the road again as if nothing had happened.
I figure the pump for some reason is overheating and thus causing it to blow the fuse. Any Ideas???
Also how and where can i get a replacement pump. Ive heard that some cheyy truck pumps may fit.
The car is a 91 model, and has sat idel since 1994 till about 12 months ago , can that be a contributing factor if the pump is the problem.
Does anyone have the part no"s for the pumps and should I replace both pumps.
Any advice would be most appreciated. Keep in mind I live in Australia and parts are very difficult to get.

Regards Ernie.

 

[Wegone]

Check out the ZR1.net ..you can use the fuel pump the from one of the trucks they have the part #s and a how to..

Steve

http://zr1netregistry.com/fuelpump.htm

 

[Hib Halverson]

The pump is fuel cooled.

I am going to guess this is not a case of the pump "overheating" and blowing the fuse.

I'm going to guess that you've got an intermittant short in the fuel pump circuit somewhere, perhaps even inside the tank. I say this because you say this problem only occurs when driving on windy roads. It is possible that the shaking and jostling that occurs during aggressive driving is causing the pump wiring to rub on something. It's also possible that this has actually rubbed through the wire's insulation and that's causing the short.

You can try changing the pump but, before I'd do that, I'd troubleshoot fuel pump wires and connections.

 

[Warp 10]

A friend in need!

A friend of mine that owns one of the C4 variety ZR-1s has asked me to try and help him chase a problem with his car.

He had someone install larger injectors(size unknown), in his car. The car starts cold just fine or if the car has sets like overnight. Up to 9 or ten hours later, the car won't start or if it does start runs rough and smells of raw fuel.

I would guess that the injectors need trimed because of the size difference. It would be a no brainer if it were a Gen III or IV, but I have no idea of where to go to get him the right help or the right tuning device or software.:ugh

Failing that does anyone know a tuner in the North LA area or the SF valley that can fix the car?

Thanks!

Bill

 

[ernbuild]

The pump is fuel cooled.

I am going to guess this is not a case of the pump "overheating" and blowing the fuse.

I'm going to guess that you've got an intermittant short in the fuel pump circuit somewhere, perhaps even inside the tank. I say this because you say this problem only occurs when driving on windy roads. It is possible that the shaking and jostling that occurs during aggressive driving is causing the pump wiring to rub on something. It's also possible that this has actually rubbed through the wire's insulation and that's causing the short.

You can try changing the pump but, before I'd do that, I'd troubleshoot fuel pump wires and connections.

Checked wiring and could not find anything. Have since learnt that GM Australia has had same problems with there Rodeo,s . It seems our new blended fuel has been causing overheating problems with fuel pumps and causing the same problem. I would almost swear that the only times I blew fuses were the times I used blended fuel.I dont normally.
Have replaced both pumps anyway, and havent had a problem since.
One bonus however is that she will now rev to 8000 rpm.

Cheers Ernie

 

[bradslt5]

A friend of mine that owns one of the C4 variety ZR-1s has asked me to try and help him chase a problem with his car.

He had someone install larger injectors(size unknown), in his car. The car starts cold just fine or if the car has sets like overnight. Up to 9 or ten hours later, the car won't start or if it does start runs rough and smells of raw fuel.

I would guess that the injectors need trimed because of the size difference. It would be a no brainer if it were a Gen III or IV, but I have no idea of where to go to get him the right help or the right tuning device or software.:ugh

Failing that does anyone know a tuner in the North LA area or the SF valley that can fix the car?

Thanks!

Bill

if anyone could help it would be steve rideout of powertraindynamics in huntington beach .o know he has the zr1 software .

 

[Hib Halverson]

A friend of mine that owns one of the C4 variety ZR-1s has asked me to try and help him chase a problem with his car.

He had someone install larger injectors(size unknown), in his car. The car starts cold just fine or if the car has sets like overnight. Up to 9 or ten hours later, the car won't start or if it does start runs rough and smells of raw fuel.

I would guess that the injectors need trimed because of the size difference. It would be a no brainer if it were a Gen III or IV, but I have no idea of where to go to get him the right help or the right tuning device or software.:ugh

Failing that does anyone know a tuner in the North LA area or the SF valley that can fix the car?

Thanks!

Bill

The injectors may or may not need to be trimmed with a new calibration, however, your symptoms sound like a classic case of faulty or leaking injectors. Of course, with "new" injectors, that would be unusual but not impossible.

First, I would run the fuel pressure diagnosis listed in the factory service manual which is intended to help you determine if you've got a bad injector(s).

That said, if this car is stock or near stock, you do not need "larger" injectors. In fact, larger injectors are generally not a good choice in modifications unless it's documented that the engine needs injectors of higher flow capacity.

If you run the fuel pressure tests and find bad injectors, I'd put new, stock-sized units in the engine.

 

[Hib Halverson]

(snip)
One bonus however is that she will now rev to 8000 rpm.

Cheers Ernie

That's real interesting as the rev limiter is at 7072 RPM.

I would caution you that if the stock rev limiter suddenly became disabled after the cal "flipped a bit" (I heard there are more cosmic rats and so forth down under), not to rev the motor to 8000 very often.:L

 

[ernbuild]

That's real interesting as the rev limiter is at 7072 RPM.

I would caution you that if the stock rev limiter suddenly became disabled after the cal "flipped a bit" (I heard there are more cosmic rats and so forth down under), not to rev the motor to 8000 very often.:L

Point taken!! balanced long tube extractors + no cats and 3 inch twin system+ Marc Haibec chip and fidanza flywheel, do help it get there.
As you say not often and fairly pointless. cheers Ernie