Questions about the fuel injector assembly 97 305 CSFI

[John from Canada]

I bought an old GMC van that I want to fix up. It was running all right, but I only had it about a day before I started taking things apart to track down a squeaking noise coming from the alternator pulley. While I was doing that I noticed a lot of gunk on the front of the engine which I found out was caused by the RTV sealant on the lower intake manifold gasket failing so I decided to keep going and replace that as well.

 

This is a big job, and not knowing the history of this vehicle, I'm kind of stumped as to what else I should replace as I go about putting it all back together.

 

My main concern is the fuel injection system, because it was a lot of work opening up the van and I don't want to overlook something that could lead to the van not being able to run.

 

It appears I have the stock CSFI version with the poppet valves. I read somewhere that most fuel injector failures are actually caused by the fuel pressure regulator failing. It could leak, causing fuel to burn one of the injectors. Or there won't be enough PSI to open the injectors. Individual injectors are prone to varnish building up on the tips of the injectors.

 

I'd prefer not to spend $300 on a new MFI assembly. Fuel pressure regulator is only $30-40, and $20 for a full set of O-rings. Suppose I do have a bad injector. Can this cause a no-start condition?

 

Is there any way to bench test or clean the varnish from the injectors while I have them out of the vehicle? Or should I just bite the bullet and buy the new injector assembly?

[grampadirt]

I'd say if you're going to keep the van and it has a lot of miles on it replace the spider with the MPFI upgrade.Delphi makes a nice one,I did it on wifey's '99 350 in her Suburban last year and made a big difference in fuel mileage and performance.

 

 

Oh,welcome to GMT

[txab]

I'd say if you're going to keep the van and it has a lot of miles on it replace the spider with the MPFI upgrade.Delphi makes a nice one,I did it on wifey's '99 350 in her Suburban last year and made a big difference in fuel mileage and performance.

 

 

Oh,welcome to GMT

 

 

+1

[John from Canada]

I guess it's anonymous. Stupid question does the MPFI assembly include the fuel pressure regulator?

[grampadirt]

Yes,it does.here's a pic of the upgraded MPFI,the FPR is the shiney round thing at the end of the control module.

[grampadirt]

BTW,after guessing and replacing some parts and wifey's burb still wouldn't run I decided to get it to our local dealership and have them put their machines on it,they diagnosed the problem perfectly.Best $125.00 I ever spent You might consider it.

[Coolmaker]

I did the MPFI upgrade on my son's 2000 GMC Vortec, and on my 2001 GMC 5.7 Vortec, they are among the best upgrades available now a days. Both work vans increased MPG and driveability.