Fuel Pump Bad?

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Trenton

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Yes, very possible. I had trouble cold starting mine for several months, I would have to use ether to start it, with a lot of suggestion as to what might be causing the cold hard start. I was told after I had it fixed that the pump was only putting out 45 PSI and needed 60, give or take a little. I also couldn't get more than about 3500 RPM before it fell on its face. So I would suggest having a fuel pressure check too, might narrow down your issue.

I just went ahead and ordered a new Delphi fuel pump. Pretty much everything else is new on the truck as far as ignition and fuel filter. It had great cold starts but was a little rougher when it warm.
Given the lack of a pressure tester, try putting some starter fluid in the air intake. If electrical is good then it will at least burn off the starter fluid. If that happens, and you are a bit shy of pressure, it might continue to run. If you can't get it to turn over with starter fluid, it might not be fuel pressure (trouble with electrical or FI, perhaps). If it turns over and doesn't continue to run it might well be fuel pressure or something with the FI. Do you have sequential or multi-port FI?

As far as i know, the truck still has the factory CSPI, but I planned on upgrading to the MPFI at some point.
 

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I just went ahead and ordered a new Delphi fuel pump. Pretty much everything else is new on the truck as far as ignition and fuel filter. It had great cold starts but was a little rougher when it warm.


As far as i know, the truck still has the factory CSPI, but I planned on upgrading to the MPFI at some point.
My 97 still has its original spider injectors. 265,000 miles, and still running good.
 

stutaeng

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I just went ahead and ordered a new Delphi fuel pump. Pretty much everything else is new on the truck as far as ignition and fuel filter. It had great cold starts but was a little rougher when it warm.


As far as i know, the truck still has the factory CSPI, but I planned on upgrading to the MPFI at some point.

Wait, so how did you determine it was the fuel pump? I thought you said you couldn't get a fuel pressure gauge? Maybe I missed something?

Could be something else. I know you said everything is new, but even new parts fail. I assume you checked for spark and your other typical checks for a non-start condition? Just trying to help not change something that may be working. Did you spraying carb cleaner in the throttle body?

I've never changed a fuel pump, but know they are a) expensive and b) not easy to change.
 

Trenton

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Wait, so how did you determine it was the fuel pump? I thought you said you couldn't get a fuel pressure gauge? Maybe I missed something?

Could be something else. I know you said everything is new, but even new parts fail. I assume you checked for spark and your other typical checks for a non-start condition? Just trying to help not change something that may be working. Did you spraying carb cleaner in the throttle body?

I've never changed a fuel pump, but know they are a) expensive and b) not easy to change.

Well I'm the type of person to change parts even if I'm worried about it maybe failing. Plus $150 for a Delhi fuel pump isn't bad at all, and with an almost empty tank I'm not hurting to put it in. I had to take my uncle (since I was borrowing their suburban) up north an hour so I just went ahead and rented a fuel pressure gauge there. Max I got was like 10 psi from the port lol.
It's always been in the back of my mind since I bought the truck to replace the fuel pump. The gauge reads a whole half off, that's what the fuel pump says. I verified it wasn't a bag gauge. Also, he said he replaced it, but I assume he either used a cheap brand or a junkyard part knowing that guy. I figured it was a matter of time before it went out on me.
 

Trenton

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Wait, so how did you determine it was the fuel pump? I thought you said you couldn't get a fuel pressure gauge? Maybe I missed something?

Could be something else. I know you said everything is new, but even new parts fail. I assume you checked for spark and your other typical checks for a non-start condition? Just trying to help not change something that may be working. Did you spraying carb cleaner in the throttle body?

I've never changed a fuel pump, but know they are a) expensive and b) not easy to change.

Well I'm the type of person to change parts even if I'm worried about it maybe failing. Plus $150 for a Delhi fuel pump isn't bad at all, and with an almost empty tank I'm not hurting to put it in. I had to take my uncle (since I was borrowing their suburban) up north an hour so I just went ahead and rented a fuel pressure gauge there. Max I got was like 10 psi from the port lol.
It's always been in the back of my mind since I bought the truck to replace the fuel pump. The gauge reads a whole half off, that's what the fuel pump says. I verified it wasn't a bag gauge. Also, he said he replaced it, but I assume he either used a cheap brand or a junkyard part knowing that guy. I figured it was a matter of time before it went out on me.
 

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Did you check the fuel pressure after you replaced the pump?

I'm surprised it ran at all with 10 psi fuel pressure. Makes me wonder if the gauge you rented was accurate.
 

stutaeng

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Ok, understood. 10 psi is very low. And where did you buy the fuel pump? I see Rockauto has the best price. Local auto parts store are more expensive!

So everything is working well now?

BTW, is the website working strangely? Double posts? Slow?
 

df2x4

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Yeah, there's something going on with the forum for sure. I just posted a thread in the help section and tagged the mods/admins to notify them.
 

Trenton

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Did you check the fuel pressure after you replaced the pump?

I'm surprised it ran at all with 10 psi fuel pressure. Makes me wonder if the gauge you rented was accurate.

Oh no I actually tested the fuel pump when I left Texas maybe 3 months ago and it read within spec. It was only until the other day did it stop working.

Ok, understood. 10 psi is very low. And where did you buy the fuel pump? I see Rockauto has the best price. Local auto parts store are more expensive!

So everything is working well now?

I have yet to find out, because I have yet to install it. Long story why, work mainly. Indeed, I did buy it from Rock Auto! Most of my parts come from Rock Auto or Summit Racing, anyway.
 
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