Low voltage to fuel pump

[TommyB]

Hi all. All was going great with my C head, Termi/GT 500 conversion until it just died after warming up before going for a drive. The fuel pump just quit. There is a BAP without any boost control etc. Measured voltage at the pump and am getting g 3.8v. Disconnected the BAP and am now getting 6.6v .
Checked the relay (not at ccrm) and it is good ,, but not engaging when the key is turned to the on position.
Not sure if I did the right thing, but have purchased an Aeromotive 340 to replace the stock pump and BAP combo. My wiring skills are not fantastic, but can usually get things done with a little help.
Anyone?
Cheers
Tom

 

[bryantaylor]

low voltage means high resistance, so there is corrosion or a damaged wire somewhere. what year and model?

 

[SVTdreamin04]

So you checked voltage at the pump only? Did you check it at the BAP?


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[TommyB]

So you checked voltage at the pump only? Did you check it at the BAP?


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It is a 98 cobra donor in a Factory Five Roadster. The engine management is stock cobra stuff with a base tune to delete all emissions and account for the mods.
I checked the supply voltage to the BAP, which was 6.8v. Output from the BAP was 3.8v.. weird.

 

[TommyB]

It is a 98 cobra donor in a Factory Five Roadster. The engine management is stock cobra stuff with a base tune to delete all emissions and account for the mods.
I checked the supply voltage to the BAP, which was 6.8v. Output from the BAP was 3.8v.. weird.

Just got back from holiday and spent some time with the voltmeter. After a little research, I found there is 12v constant going in to the CCRM (pin 11). With ignition on, there is only 6.5 v going out(pin 5). Still getting the 6.5v at the pump and inertia switch. This ,I assume tells me the CCRM is toast.
Am I correct?. If so, what would be the cause? Could the BAP be drawing too much for the stock wiring and generating too much heat at the CCRM?
I am thinking of replacing the BAP and stock pump with an aeromotive Stealth 340lph unit, Which I already have.
Thanks for the help
Tom

 

[mcaligiuri]

Just got back from holiday and spent some time with the voltmeter. After a little research, I found there is 12v constant going in to the CCRM (pin 11). With ignition on, there is only 6.5 v going out(pin 5). Still getting the 6.5v at the pump and inertia switch. This ,I assume tells me the CCRM is toast.
Am I correct?. If so, what would be the cause? Could the BAP be drawing too much for the stock wiring and generating too much heat at the CCRM?
I am thinking of replacing the BAP and stock pump with an aeromotive Stealth 340lph unit, Which I already have.
Thanks for the help
Tom

yes you are correct, the ccrm has relays inside it and probably the contact has resistance on it. maybe you could find the pin outs on the board and wire in a remote relay to bypass that one. would save you the price of buying a ccrm.

 

[TommyB]

yes you are correct, the ccrm has relays inside it and probably the contact has resistance on it. maybe you could find the pin outs on the board and wire in a remote relay to bypass that one. would save you the price of buying a ccrm.

Hey, thanks for the help. I bought an Ebay unit for 40 bucks in anticipation of this. I pick it up Monday.
Will give an update next week.
I also plan on replacing the stock fuel pump with a walbro 255 and ditching the BAP.
Have a great weekend
Cheers
Tom