FOURSPEEDVETTE

A mechanic suggested I replace the fuel pump at the same time I replace the fuel injectors and fuel pressure regulator. He said that the fuel pump may go bad because I would have all new parts installed and the old pump would have to work harder. Is this possible?

gerardvg

No
The fuel pressure will remain the same, the pump could not care less if you have new injectors.
How old is the fuel pump? I only got 10 years from the fuel pump,
they are dirt cheap so buy one and forget it for 10 years.
A tow costs 10x the price of a fuel pump ..... new pump is cheap insurance.

aklim

Is this your regular mechanic? If so, he should be your ex- mechanic. Injectors are a set. If you replace them, replace them as a set. Also send out your cold start injector for cleaning. Obviously you need new gaskets. Take apart the TB and clean it. The rubber is old on the FPR so while you are there.

As for the pump, replace it only if it isn't working right. Do a WOT run test, leakdown test and see what is going on. Otherwise, he is either trying to fleece you and it is part of his habit or he is an idiot.

aklim

My pump lasted for a long while. More than 10 years. I changed it because I was going with a higher performance engine and I wanted a bigger pump for more room. Most of my other cars don't have the pump changed unless they are broke.

According to the idiot lore going on, I should be replacing them every week. You see, I run my tank to empty and it would suck up debris and/or the pump wouldn't be able to cool itself in the fuel bath and burn up. Also when the car is not running, I take my battery out and put it on the bare concrete floor.

FOURSPEEDVETTE

I am replacing all these parts just as preventative maint. and because they are the 33 year old originals with 51,000 miles on them. Strangely they all still work fine. Just old.
List of things I already have and ready to install in my bone stock 1985 L98:
1. all 8 (24lb.) matched rebuilt injectors & "O" rings from F.I.C.
2. a new fuel pressure regulator diaphram & spring assm. from F.I.C.
3. all new plenum gaskets from F.I.C.
4. a new EGR valve & gasket
The throttle body has just been removed, cleaned and new gaskets installed. The original fuel pump works perfectly so I don't intend to replace it now if I don't have to. And no, this guy has never worked on my car before although he is an ASE mechanic. I was just a bit nervous when he mentioned that my fuel system may act up if I don't change the fuel pump.

aklim

So far you did a lot of solid work. The older injectors could be the old Multec ones which are not tolerant of ethanol and you can't get non-ethanol gas readily. At least around here everything but a couple places has ethanol so it has to be a lot of work to always get it from that place. Kinda why I don't want to have to hassle with it on longer trips since I fill up only when empty. That said, a couple of questions.

Did you get the cold start injector serviced, while everything is out? FIC does that.

When you cleaned the throttle body, did you take the IAC solenoid out and gently spray the pintle, clean all passages with the IAC housing off and the top plate off? Reassemble with fresh gaskets? Many people don't do that part. I'd also have done the coolant bypass which makes it easier to take off in future.

I don't care if he is ASE or God certified. He should know better. So either he is an idiot or trying to bend you over and shove it in without lube. Run like hell.

383vett

If your mechanic was honest, he would have told you it might be a good idea to replace the parts because they are old, not that the new injectors may cause them to fail. Bail in this guy and buy a fsm and learn to work in your own car.

aklim

That logic I can go with. After all, the pulsator is rubber and rubber breaks down after a while. I can't imagine using a 30 year old rubber but that he said that the old pump has to work harder with the new injectors makes me think he is dishonest or stupid. From what I see, the pump overpressures the system by design and the regulator keeps it in place. Pump is too stupid to know what is in the system.

FOURSPEEDVETTE

The cold start injector will be taken care of. Yes, the throttle body was done exactly as you stated. The throttle body coolant passage was incredibly clean and no damage inside. As far as the mechanic, no, he's not my mechanic. He was just I guy I spoke with who is a mechanic.

FOURSPEEDVETTE

Honestly, I do alot of my own work and I do have a FSM. The comment the mechanic made just seemed a bit strange to me. I had never heard of his suggestion being something I should consider. I agree that the fuel pressure regulator controls the pressure. Not the fuel pump.

aklim

Then life is good.

OK. When I go to a shop for work I cannot do (tools or beyond me), I normally discuss with the mechanic what I need done, how long it takes, what parts are needed, etc. After which, I go to the Service Advisor and tell him "I want XXX doing this job. It should take YYY hours and I ordered the parts already. What day can we do this?". If XXX is not there that day, I reschedule. I am VERY particular about my mechanics. If he isn't your mechanic, fine. Don't ever let him work on it. my $0.02

aklim

And you wonder why I don't let my wife talk to mechanics? All she can do is get the keys from the counter. Do not talk to the mechanics. If they have any questions, they can call me. I already paid. Do not look at them in the eye. Last time she did, they talked and got my mechanic confused since I was supposed to be handling that part of the job and he called me to confirm.

Some things she handles and I rubber stamp like my doctor's questions and some things I handle and she doesn't get involved. Less confusion.

mickey5

Just curious, my '90 has the original pump and 50K miles. Do they normally just fail suddenly or does it warn you its time to change?

aklim

Pump can be sudden as can injectors. Multecs are not going to get along with ethanol and. Most gas has some. That I would change. They get clogged slowly so you won't notice that it is going south till it is really bad.

pacoW

I've had a couple (not corvettes but GM products) that got louder before they failed. Of course I never put 2 and 2 together until I'm stuck in a walmart parking lot. Then put walbro pumps in and they're twice as loud as the failing ones even though they working great.

aklim

Why would you put 2 and 2 together? You were busy. When the car broke down, you had time to think while waiting for the tow truck

Tom400CFI

Ha ha ha...my good friend w/a '88 5.0 had a noisy, "grinding" fuel pump. I told him as he was leaving my house one day, "You better replace that soon before it takes a dump on you".

"No, no", he says, "fuel pumps don't just go out on you, it'll start to lose power first before it dies. I'll change it then."

I told him I didn't agree with his prediction, but whatever. He left my house. About 25 minutes later he called me...fuel pump took a dump, and I got to go help him change it...in the Walmart Parking lot.