zaydog3

I had a mechanic install a Bosch 69218 fuel pump in my 1986 Coupe. I picke the car up and drove it around and stopped at several places. Everytime it started back up. I let it set in the garage for a week and when I went to start it up it would turn over but not start. I squirted some starter fluid into it and it started briefly. I had it towed back to the mechanic and he told me that they bench tested the pump and it ran ok but when they put it back in it was only pushing 4lbs of pressure and that it was defective. I asked how could it go bad when the car was just setting in the garage and he tried to tell me that it was because it was an electronic device and they could go bad at anytime (I am an electrical engineer and did not buy that at all). Of course he wanted to purchase a pump for me and charge me additional labor but I opted to take advantage of my warranty and get a new pump. I bought the pump from Rock-Auto and they said that of all the pumps they sold, they had only one come back defective and that they had sold quite a few. My question is - can a fuel pump go bad just sitting around? I am thinking that it was not installed properly and that something came loose. Anyone have any thoughts on this?

96GS#007

Sure, sh*t happens. Unusual yes, but it can occur. If it works fine with the new pump, I'd say that's pretty telling.

If it happens again, then you can dive in and start looking for other issues that might be killing the pump.

1bdvet

I ran services dept, for 15 years, and I think we had 1 failure couple months later which we service parted, and installed new one at no charge to the customer.
When I had C4, had the pump and screen replaced, due to failure on the sending unit, but while it was out replaced, and drove it another 86,000 with no problems, then sold the car still going to strong, friends drive it, but lets me borrow it when I want to drive ragtop.

KYC4

Something seems off here...it COULD be bad but didn't your mechanic take the car for a drive after the install to check that it was operating as it should?

Later,

Lee

solaris_vii

having a mechanic do a fuel pump in a c4 in general is a rip off. when i was younger i paid 600 to have one replaced, didnt even fix the problem (injectors) and gave up on the car. next c4 i had i changed it myself as preventative maintenance. its a 20 minute tops procedure, four torx screws take the fuel door off and then i think eight 10mm bolts get the pump and sending unit out. kick this jerk to the curb, get the warranty one from rock auto, and change it yourself

DanielRicany

I think when you go to a mechanic for help, you should let them supply the parts. As bad as it seems, this is the types of problems that you can run into. Out of all my buddies who own repair shops, they will not warranty repairs on parts that were not purchased by the shop itself. Which is true. I mean, I have the same point of view. If I don't supply the product, how can I warranty it?

Not trying to be mean just trying to be helpful. But the fuel pump on these cars is so simple it's ridiculous.

MRPVette

I put a brand new fuel pump in my GMC truck a few years back and it crapped out about 2 weeks later not very common but it can happen, I install most parts myself but if I hire someone I always let them supply the parts and labor that way I am covered if the part goes bad.

zaydog3

I drove it myself and made several stops it started and ran just fine. My old pump worked but was making a whining noise that's why I got it replaced. I did not hear the noise from the new pump. All I did was park it in the garage and it set for a week and when I went to fire it up, it wouldn't start. The Bosch pump is an upgraded pump and has its own installation instructions. If I had 3 dollars, I would bet you 2 that they did not install it properly and are trying to make me pay for them finding that out. I am going to wait to see what happens before I start pulling some rabbits out of my hat.

zaydog3

I drove my car around for a day with no problem. It set in my garage for a week and when I went to start it - it wouldn't start. My confusion is that the pump was shut off for a week.

zaydog3

The original pump worked but was making a whining noise but I had no problems starting and running the car. So my thoughts are that nothing is killing the pump - I just think they did not install it properly and while the car set for a week something came loose. I think they know what the problem was and are just trying to recapture the labor they spent finding it out which they should eat since they did not do the job right. It will be interesting when they get the new pump.

Cruizin

Your mechanic says the pump is still running but only building 4lb pressure.

Some possible causes:

1. Pump or pulsator has come disconnected from the coupling hose or coupling hose has split and is bypassing most of the fuel back into the tank.

2/ Pump filter sock is blocked

2/ Blocked fuel filter

3/ Pump is not getting full voltage and spinning slow

4/ Fuel pressure regulator is faulty

zaydog3

My original pump was functioning well (fuel pressure regulator should should still be good) - just whining so I decided to replace it. The strainer and fuel filter were both changed at the same time as the pump, and the pump was working fine when I parked it in my garage.

So your first option has merit - If true then replacing the pump will not fix my problem. I will see this week.

solaris_vii

those pulsators can go bad and develop a leak, i just always replace with a piece of fuel rated hose. no more problems!

hooked073

It is easy to jump on the shop fact is seldom do good shops mess up does it happen yes but the fact is if a shop has been around for 5 yrs or so it is not because they a ripping people off. I could give you a list of crap pumps that I installed not on C4 but on other vehicles. Had a ford ranger come into the the shop needed a new tank replaced the tank and pump a week latter truck ran like crap fuel pressure real low pulled tank reaplced pump good to go week latter same thing pull pump replaced good to go 2 days latter same thing I said screw this put on a ford pump at 3 times the cost truck is running to this day. People there is crap out there. Check out all the articles on cheep C4 headlight motors. Sometimes you get what you pay for with electrical parts I think this is more then true

zaydog3

I bought a Bosch fuel pump that cost approximately the same as a AC-Delco. I bought because it was an upgrade and advertised to run quietly. I talked to my mechanic and he assured me that they tested everything and the pump was indeed bad. I am getting another one from the manufacturer since the one I have is still under warranty. If it is defective this time, I will get my money back and buy the AC-Delco. Thanks for the input.

Paul Workman

Just FYI...

Failure analysis or Mean Time Between Failure (MTBF) statistics for most manufactured "stuff" has two regions of high failure rate: The first period, called the "infant mortality period" is when the device is initially put in service. The second is after the device has been in service for a period of relatively low failure and begins to wear out - i.e., which statistically defines the "service life" when failure rates cross the threshold of "acceptable" failure levels.

The interesting piece is, the most severe failure period in terms of % of devices that fail and fail over the shortest period of time in service is when they are first put in service. The "infant mortality" period is the most critical and any manufacturing flaws or flaws in materials usually appear right away. (Sounds like your pump, AND one of mine too, falls into this group!)

It may be of some comfort to know that critical replacement part assemblies installed in e.g., aircraft, are required to have been run tested successfully past the statistically determined "infant mortality" period before being certified for use.

Anywayz... I bought pumps (plural - the ZR-1 has two) for about $70 ea. and as mentioned, it only took about 20-30 minutes to do both of them from start to finish - if that helps you evaluate the amount you paid for your pump replacement. And, the check valve on one of the pumps was bad - right out of the box. Luck of the draw (typical for me, it seems!)

Funny thing: In addition to my fuel pressure being an issue - prompting my need for a new pump(s) - my gas gauge was acting erratically. But, when I pulled the pump assembly out of the tank, I spied a red shop towel floating around in the gas!! I surmised the rag was probably the culprit - interfering with the float action - and removing it resulted in the gas gauge returning to normal operation.

zaydog3

I worked as a Engineer in Manufacturing once and I am familiar with MTBF and the "bathtub" curve you described. That's why electronic manufacturers can get away with 90 day warranties (although it is a year now). If a device works within the first 90 days without failure then the odds are that it will continue to work for its specified life time. I am replacing the pump with an identical one, odds are that this one will not fail early - I will see. But since the pump that was replaced functioned but was noisy should eliminate anything floating around in the tank unless it was recently introduced there.

Thanks

Geardo

The C4 fuel pump is so easy to change, and they are inexpensive