fuel delivery

[roger longman]

Hi all, I decided to go with Hibs Airtex recommendation, in no small way, as it is by far the cheapest option. However, with the engine running, with the old pump, the pressure, at the rail, is varying from about 28 PSI to 39 PSI. Could this also be a relay, or other, problem, rather than fuel pump ? Any opinions will be much appreciated.......Roger.

 

[G Winter]

Filter, regulator , pump in that order . Unless you have a line leak .

 

[gmjunkie]

Filter, regulator , pump in that order . Unless you have a line leak .

My guess is pump or high resistance ground!

 

[roger longman]

Thanks Jesse and Mr G, fuel filter replaced last week will be replacing pump this week. Now I'm hearing bad things about Airtex and, I've ordered the 3270, which is specified for '92 and up but, I'm thinking it'll be OK in my '88, any thoughts anyone ?.......Roger.

 

[Huskerman]

Have you taken a look at the fuel pump kits from Racetronix? They feature Walbro pumps and all the other things needed to change out your fuel pump. They make a specific kit for the 87-89 C4's. If you are stock or have slightly warmed up engine, then the 190 gph pump is all you need......

I used their kit on my 90 and was very pleased with all of it. Racetronix is good to deal with also......


Sorry already posted this info earlier.......my bad!

 

[boomdriver]

Have you taken a look at the fuel pump kits from Racetronix? They feature Walbro pumps and all the other things needed to change out your fuel pump. They make a specific kit for the 87-89 C4's. If you are stock or have slightly warmed up engine, then the 190 gph pump is all you need......

I used their kit on my 90 and was very pleased with all of it. Racetronix is good to deal with also......


Sorry already posted this info earlier.......my bad!

Thats my next purchase...

My system is dropping all the pressure as rpm increases to the point that its now misfiring under heavy throttle...and I know the fuel filter is good. I can see the pressure drop off and recovery with rpm increase/decrease.. I need it to hold 45-50 psi through the 600 to 6000 rpm range., just like all other EFI engines need to have stable pressure and flow to run well.

The racetronix is a substantial bump up in gpm and it meets the pressure needs. Not outrageously expensive either.. The key is being able to maintain 45 psi (whatever your system requires) at all rpm...not just idle. If the pressure falls as rpm increase that indicates that the engine is using the fuel faster than the pump can get it there...so the engine is not actually developing all of the power that it could...if it were getting sufficient fuel. A high gpm or litres/hr pump is the answer.

 

[roger longman]

As said, I've already ordered the Airtex 3270, which they specify for '92-'96 Vettes. So it's increased volume and pressure. The figure quoted of 190 gph is incorrect, it's litres PH. 190 GPH, I think, would be for the Bugatti Veyron......Roger...