Worked on O2 wires, now no fuel pressure

[Funracer]

Hi all

I have owned my 91 ZR1 since 93. Today I decided to cut some
solder splices from an extension added to the right side O2 sensor wires many years ago. I had added 18 inches or so to the sensor wires in order to rerout the wires around the headers I installed back then. The solder had corroded green underneath the heatshrink and began to
crumble. My plan was to cut them out and replace with crimp splices. I read somewhere that solder does not work well with O2 sensors but
crimps are OK.

In any case, the car started as normal, I drove it onto my ramps, shut off the ignition. Next day I slid under, cut out two of the six splices and then remembered I had not
disconnected the battery. I unhooked the negative post and then completed my splice replacements.

When I went to start car to remove it from the ramp the starter engaged as normal but no start. Starter tuning engine but will not fire.

Since then I have checked: ECM shows 12s only no other codes, CCM codes C12 only (good?), no CCM ERR message, spark is good, added 5 gallons fuel, all fuses in main and aux panels good,
replaced the MEMCAL chip with a spare that was working when I took it out, and charged battery.

On each start I can hear a fuel pump run for 2 seconds so I assume FP relay OK. Both FPs and all FP and tank system filters were changed last fall. Attached fuel pressure guage and it reads zero PSI while cranking.

Here are my questions:

Could clipping 2 O2 sensor wires with key removed but battery attached cause this or is it just a coincidental failure?

If I can hear the fuel pump run for 2 secs how can the fuel pressure be zero, assuming my test guage is working properly. After many start attempts I never smelled any fuel in the engine compartment or anywhere else.

If I mucked up the resplicing somehow wouldn't the car at least start? O2 not part of start (open loop) parameters until idle (closed loop) if I remember right. The car should start even if they are unplugged.

So the crux of it is I can hear pump(s) at key on but no fuel
pressure then or during cranking.

Any ideas? Thanks

Neil in Ft. Walton, FL

[tpr60]

Should have fuel pressure over 40psi after pumps run for 2/3 secomds. Bad pumps or test gauge.

[Paul Workman]

As tpr60 indicated, if you hear the pump(s) run, you should have pressure at the rail, and even with the switch off, pressure should hold to within a pound or two for several minutes.

In a recent post there was a question about checking the fuel pumps to see if they're running. IF you have your fuel pressure gauge connected (AND, it is working properly...) you should read approx 50-52# at the Schrader valve while conducting a current draw test to verify both pumps are running.

C-LINK, post #7...

This test should tell whether the pumps are working - at least when all the normal circuitry is bypassed (during this test). IF you have between 8-10A draw, AND fuel pressure holds after the current is removed, we'll know the the fuel system itself is OK, including fuses AND the pressure gauge, etc. If this all checks out, then we can turn to "next steps".

Solder...

When the EPA, in their usual "infinite wisdom" or rather their usual perpensity for solving problems that didn't exist and making them worse in the process - - mandating the lead be removed from solder, and replaced with silver, or the like, is a classic case of "if it ain't broke, don't fix it!" By my observation, and not to imply anything scientific, it seems I run across solder joint corrosion issues with the "new improved" solder out of proportion with the time and amount it has been used, when compared to the good ol 60/40 lead/tin solder. Even when exposed to salt air (US Navy) I don't recall the frequency of a solder joint failing in the same proportion that what appears (to me) to be the case with today's stuff. (You didn't use plumber's solder, or acid flux core solder, did you??? No, I didn't think so...)

That said, side by side and given exposure to the same elements, I would bet the solder connection would be supior to the crimp connector, hands down. (Again, from experience with salt enviornments). What's more, unless the shrink sleeves used to protect the connection have a weather repellant goo inside the tubes, the dang things will wick water into the connection - the exact opposite of what the purpose of the shrink sleeve was in the first place! (FWIW, I coated my O2 solder connections with RTV before shrinking the tubes over the connection. So far, so good.)

P.

[Funracer]

"

As tpr60 indicated, if you hear the pump(s) run, you should have pressure at the rail, and even with the switch off, pressure should hold to within a pound or two for several minutes

Yes I should, but I do not. Even if I press on the Schrader valve after
key on and/or during cranking, not a drop comes out. That seems odd.

I changed both pumps and in tank filters in the fall. I have started the car several times since then with no issues. If the pump or pumps come on for two seconds at key on (I can hear it), it seems like something should come out of the rail.

Is there an ECM failure that would account for this? Failed check valve?
Hose came off in the tank? Line blockage? Secret fuse somewhere?

I am using the crimps because I read that solder changes the resistance
of the wire and O2 sensors are not designed to work with solder in the line. I was getting an idle stumble and decided to remove the solder that I had put there about 12 years ago. When I stripped away the tape and
shrinkwrap I found the solder was crumbling and the wires and solder
had all turned green. I read in the same article that crimps are better
for O2 wires b/c they dont change the properties of the wire. If the
crimps do fix the idle problem, ultimately I will rebuild the O2 loom and
eliminate the crimps as well.

When I get home next week I will perform the pump test to verify they are running. I can also change the main under side fuel filter. I changed
it many years ago but it has very few miles on it since then.

Still no start in the Florida Panhandle

[Funracer]

Update:

I did the fuel pump test today as described here:

http://www.zr1.net/forum/showthread....hlight=amperes

My DVM showed 5.37A draw steady. I guess this indicates 1 pump
running and 1 not or very weak. Fuel pressure at the Schrader valve
during the test was again zero. I have not been able to test the guage
yet on another car but when I push the Schrader valve nothing comes out. Obviously there is no pressure in the rail.

What now?

Thanks

[tomtom72]

I'll toss this out as a fwiw. I did a pump swap a coupla of yrs ago and all was well for a while and then no F/P one day.

Pulling the assembly from the tank I saw that the plastic clamp at the top of the out hose was cracked and not clamping anything so the fuel was just not leaving the tank. If you reused those OE plastic clamps you may want to check them for failure. I also remember another member having an issue with the brand new pumps that came with the replacement sender+pumps unit from Delphi. We all jumped on this buy from e-bay Partsladie. His brand new pumps stopped working after a short time in service.


Tom

[scottfab]

Before I'd go any further I'd try this. Sometimes when reconnecting the batter I noticed strange ECM behavior. If reconnecting the battery is not done cleanly it can scramble the ECM. I've cleared this by disconnecting for a minute and then reconnecting cleanly (quickly).

[Funracer]

Originally Posted by tomtom72

I'll toss this out as a fwiw. I did a pump swap a coupla of yrs ago and all was well for a while and then no F/P one day.

Pulling the assembly from the tank I saw that the plastic clamp at the top of the out hose was cracked and not clamping anything so the fuel was just not leaving the tank. If you reused those OE plastic clamps you may want to check them for failure. I also remember another member having an issue with the brand new pumps that came with the replacement sender+pumps unit from Delphi. We all jumped on this buy from e-bay Partsladie. His brand new pumps stopped working after a short time in service.


Tom

OK thanks Tom. What you describe makes sense
based on the symptoms I have. I have been avoiding pulling
the pumps again because I had a b e a t c h of a time
getting the assembly back in the tank last time.

If I find a problem I will document with pics and post.
Unfortunately I am leaving on business tomorrow and
wont get to it for a couple of weeks.

Regards

[Funracer]

Originally Posted by scottfab

Before I'd go any further I'd try this. Sometimes when reconnecting the batter I noticed strange ECM behavior. If reconnecting the battery is not done cleanly it can scramble the ECM. I've cleared this by disconnecting for a minute and then reconnecting cleanly (quickly).

I tried this early on, but only once. I will try again
just to make sure.

Thanks

[VetteMed]

Originally Posted by tomtom72

I'll toss this out as a fwiw. I did a pump swap a coupla of yrs ago and all was well for a while and then no F/P one day.

Pulling the assembly from the tank I saw that the plastic clamp at the top of the out hose was cracked and not clamping anything so the fuel was just not leaving the tank. If you reused those OE plastic clamps you may want to check them for failure. I also remember another member having an issue with the brand new pumps that came with the replacement sender+pumps unit from Delphi. We all jumped on this buy from e-bay Partsladie. His brand new pumps stopped working after a short time in service.


Tom

Yes, that would be me, I posted about my "New" pumps failing within 500 miles of installation, which is what prompted me to install the Bosch Turbine pumps (minor mods required).

Andrew