code 55 still

[aafc]

When to a test and tune at Orlando Speed World Sunday the 19th.
Place was full , wait time to made a run about 1.5 Hours!, meaning I got 2
runs, code 55 come up again. Ok so after last run packed up and left track, I
got about 5 miles and I saw my fuel pressure drop to 35 lbs car run fine No
big deal I was running low on fuel so stopped and filled up. start car and fuel
pressure was back up to 43 lbs. Pumps were replace 2 months prior, today I
checked current draw reading was 9.22 amps. pulled fp1 fuse and took a
reading and got 5.24 amps. so what is my choice . change the (*primary fuel
pump) or replace the fuel pressure (original 31 year old ) regulator with the
new unit from Jagpanzer.
thanks for your input
John

[ZWILD1]

You say it was running fine. I know when my FPR went the car just didn't feel the same. It didn't pull as hard . Since it had the original injectors I got new ones from white racing that were flow matched. Same feeling . Replaced both pumps with new GM ones and new hoses and socks. Car still felt not as good wide open throttle. Talked to Marc Haibeck and he said only thing left is the FPR . Ordered a new one as they were still available in 2008. It needed the injectors . The pumps were probably okay . The FPR had it running like before . With everything else it was even better. I could not test the fuel pressure while driving . I should have gotten a longer line for the gauge . Point being you should notice a difference at wide open throttle if it's not doing its job. I sure did.

[ZWILD1]

I forgot to say it had zero codes . Nothing .

[aafc]

I had some free time this week and have done the following. Pulled FP1 fuse
key on, no start 45 psi. checked the Fuel pressure regulator apply 9 hg to
regulator, held pressure ok, no fuel inside regulator.
Next I'll pull FP2 fuse and check fuel pressure. This may take awhile to get
into position to pull fuse as I will have to pull the pass seat out so I can reach
the fuse. 6 ft 185 lbs roll cage in way makes It hard, also take off the roof
panel so I can into car.
John

[aafc]

Alright, update: I realized after removing the top and passenger seat I
still could not get under the dash on the passenger side. So I made a pair of
jumper wires that could connect the fuel pumps (primary and secondary)
separately without removing the fuses. Fp1 pressure 46 lbs, Fp2 47 lbs ,
pumps test ok. Current draw FP1 5.2 amps and FP2 5.1 amps. Yes I know that
the readings are a little different then before. Next is to replace the original
30+ years old fuel pressure regulator.
Made a call to Jerrys gaskets for the new improved fuel regulator and plenum
gaskets.

I'll let everyone know if this clears my at times code 55 when I go WOT.

John

[aafc]

After replacing the original FPR (30+ years old) with the new improved FPR.
Took car for a drive, warmed up car until everything was warmed up. Pulled
to side of road and waited for light traffic to clear. Pulled out (Auto 4l8OE)
in drive and made a WOT run, 2nd gear shift at 7000rpm, front end came up
and pulled the rear to the right ( I was ready for It) got up to 85 mph and let
out. Made a second run up to about 90 mph and let it slow down to 55-60
mph. Pulled over and checked the TECH 1-A no trouble codes.
At this point I believe I fixed my at times code 55.
I may take her to a test & tune this Sunday Jan.9, 2022 if weather holds.
John
1990 white/black # 2546
one of a few 4L8OE EQ. ZR-1's

[HAWAIIZR-1]

Originally Posted by aafc

After replacing the original FPR (30+ years old) with the new improved FPR.

Took car for a drive, warmed up car until everything was warmed up. Pulled

to side of road and waited for light traffic to clear. Pulled out (Auto 4l8OE)

in drive and made a WOT run, 2nd gear shift at 7000rpm, front end came up

and pulled the rear to the right ( I was ready for It) got up to 85 mph and let

out. Made a second run up to about 90 mph and let it slow down to 55-60

mph. Pulled over and checked the TECH 1-A no trouble codes.

At this point I believe I fixed my at times code 55.

I may take her to a test & tune this Sunday Jan.9, 2022 if weather holds.

John

1990 white/black # 2546

one of a few 4L8OE EQ. ZR-1's

Thanks for the update and good to hear you got it resolved with a new FPR! Now go kick some ***! 🤙🏼


Sent from my iPhone using ZR-1 Net Registry

[aafc]

Went to Orlando Speed World on Jan. 9, 2022 to make some runs. Weather
was very good high 70's to low 80's. Made 4 passes no code 55 but still
having trouble holding foot brake at 2500 rpm, so red lights and late lights.
You can watch my runs at solarshiftz click on Funday Sunday Jan 9th 2022.
1st run at 19:00 , interview at 40:17, 2nd run at 50:10 and 3 rd run at
1:15:00, 4th run could not hold car ,pushed thru brakes no time.
1st run left at 2500 rpm, pushed thru brakes. 2nd, 3rd and 4th left at
2300rpm . still had trouble holding car with foot brake. New rear brakes
came Monday. just finished installing them, they are a low metallic higher
coefficient pad, theses may work better for me.
And I still had fun!

1990 black/white # 2546
one of a few 4l8OE EQ ZR-1's
John