1991 ZR1 Restore - Help! - Page 4 - ZR-1 Net Registry Forums

kapkanimd · 02-20-2022

Did some more testing today...

Both pumps are working, but I am still only getting 18-20psi fuel pressure... on top of that if I pinch off of the return fuel line, there is no change in pressure..

As mentioned the pumps are new Advance Auto (Car Quest) E219663 pumps from a same year 7.4L Suburban.. Which I am now realizing might just be the wrong pumps.... I just ordered new GM ones (EP381).. Hopefully that helps the fuel pressure issue..

Also discovered some lovely coolant under the passenger side dash.. I am guessing from when I used the heater to test it.. fml...

kapkanimd · 03-01-2022

Update! New pumps in, car is running normal now! Finally!

However, I got it up to temp (no issues) then let it sit for a bit. When I started I got the dang 31 Cam sensor code again. The car didn?t run as rough as it used to with the SEL light and actually restarted, so still in a better place? I?ve tried 3 different cam sensors so I?m guessing it still might be a ecm issue.. I?ll run some more tests, but overall happy..

Coolant leak: I tried a new cap but still leaking.. I think it might just be corrosion at the inlet and I need a new tank.. anyone see this before?

GOLDCYLON · 03-02-2022

Quote:

Originally Posted by kapkanimd

Update! New pumps in, car is running normal now! Finally!

However, I got it up to temp (no issues) then let it sit for a bit. When I started I got the dang 31 Cam sensor code again. The car didn?t run as rough as it used to with the SEL light and actually restarted, so still in a better place? I?ve tried 3 different cam sensors so I?m guessing it still might be a ecm issue.. I?ll run some more tests, but overall happy..

Coolant leak: I tried a new cap but still leaking.. I think it might just be corrosion at the inlet and I need a new tank.. anyone see this before?

No but that tank is not ZR-1 specific and on the entire C4 run. So that's some better news. GC.

jss06c6 · 03-03-2022

Quote:

Originally Posted by kapkanimd

Update! New pumps in, car is running normal now! Finally!

However, I got it up to temp (no issues) then let it sit for a bit. When I started I got the dang 31 Cam sensor code again. The car didn?t run as rough as it used to with the SEL light and actually restarted, so still in a better place? I?ve tried 3 different cam sensors so I?m guessing it still might be a ecm issue.. I?ll run some more tests, but overall happy..

Coolant leak: I tried a new cap but still leaking.. I think it might just be corrosion at the inlet and I need a new tank.. anyone see this before?

Looks like the upper pipe nipple that is (I believe) soldered is leaking. See if it moves when you remove the hose and wiggle the pipe. If so, you might be able to remove the tank, clean and dry it and resolder the pipe nipple to the tank. Challenge will be to get the fluid out of the fractured joint so that you can effect a good repair. Absent that, it the same as the LT-1/LT-4, so you should be able to locate a good replacement.

Sent from my SM-G950U using ZR-1 Net Registry mobile app

kapkanimd · 04-07-2022

Quick update:
-Replaced the clutch master cylinder and slave cylinder (was leaking bad in bell housing)
-Replaced the coolant reservoir (however I think the heater core might still be leaking)
-Dropped oil pain, cleaned everything up, and put new gasket

Now no leaks at all and car is still running great. It is now giving me issues starting where it is just clicking.. I think it is the switch

it never did this before changing out the master cylinder..

Still left to do:
-Suspension: bushings, tie rod ends, and shocks
-Radio not working (shows the stuck time of 1:00, no sound, and no antenna)
-A/C not working (clutch not coming on)
-Paint needs fixed (clear coat missing on hood and other areas)
-Replace all the weather stripping

Turning into a long project, but hopefully worth it in the end

viper107 · 04-07-2022

Cam codes are probably due to misfire,are the injectors fat body type or plastic skinnys,I would definitely get a 94 or 95 ecm because the 91 ecm is junk from new

spork2367 · 04-08-2022

Quote:

Originally Posted by viper107

I would definitely get a 94 or 95 ecm because the 91 ecm is junk from new

Can you elaborate on this?

viper107 · 04-08-2022

every 91 i have had (years ago) the ecm went south on low mile cars (3) and back then i believe around year 97-98 they updated the part number to the later year part number/plug and play ac delco i bought them whole sale for under 200.00 brand new

kapkanimd · 04-27-2022

Quote:

Originally Posted by viper107

every 91 i have had (years ago) the ecm went south on low mile cars (3) and back then i believe around year 97-98 they updated the part number to the later year part number/plug and play ac delco i bought them whole sale for under 200.00 brand new

Do you have the part number and a source to get it?

spork2367 · 04-27-2022

Quote:

Originally Posted by viper107

every 91 i have had (years ago) the ecm went south on low mile cars (3) and back then i believe around year 97-98 they updated the part number to the later year part number/plug and play ac delco i bought them whole sale for under 200.00 brand new

I've never seen this posted anywhere but in this forum by you. That I'm aware of there is nothing particular to the 91 ecm that would support this statement.

Quote:

Originally Posted by kapkanimd

Do you have the part number and a source to get it?

They are only available on the used market.

02-20-2022	#31
kapkanimd Join Date: Oct 2021 Location: Tampa Posts: 19	Re: 1991 ZR1 Restore - Help! Did some more testing today... Both pumps are working, but I am still only getting 18-20psi fuel pressure... on top of that if I pinch off of the return fuel line, there is no change in pressure.. As mentioned the pumps are new Advance Auto (Car Quest) E219663 pumps from a same year 7.4L Suburban.. Which I am now realizing might just be the wrong pumps.... I just ordered new GM ones (EP381).. Hopefully that helps the fuel pressure issue.. Also discovered some lovely coolant under the passenger side dash.. I am guessing from when I used the heater to test it.. fml... Last edited by kapkanimd; 02-27-2022 at 10:09 PM.

04-07-2022	#35
kapkanimd Join Date: Oct 2021 Location: Tampa Posts: 19	Re: 1991 ZR1 Restore - Help! Quick update: -Replaced the clutch master cylinder and slave cylinder (was leaking bad in bell housing) -Replaced the coolant reservoir (however I think the heater core might still be leaking) -Dropped oil pain, cleaned everything up, and put new gasket Now no leaks at all and car is still running great. It is now giving me issues starting where it is just clicking.. I think it is the switch it never did this before changing out the master cylinder.. Still left to do: -Suspension: bushings, tie rod ends, and shocks -Radio not working (shows the stuck time of 1:00, no sound, and no antenna) -A/C not working (clutch not coming on) -Paint needs fixed (clear coat missing on hood and other areas) -Replace all the weather stripping Turning into a long project, but hopefully worth it in the end

04-07-2022	#36
viper107 Join Date: Dec 2019 Location: st louis mo Posts: 749	Re: 1991 ZR1 Restore - Help! Cam codes are probably due to misfire,are the injectors fat body type or plastic skinnys,I would definitely get a 94 or 95 ecm because the 91 ecm is junk from new __________________ 95 admiral blue z(sold)/ / 93 ruby z(sold) 91 steel blue z/95 aqua z haibeck 510, 91 callaway 415 areobody #5

04-08-2022	#38
viper107 Join Date: Dec 2019 Location: st louis mo Posts: 749	Re: 1991 ZR1 Restore - Help! every 91 i have had (years ago) the ecm went south on low mile cars (3) and back then i believe around year 97-98 they updated the part number to the later year part number/plug and play ac delco i bought them whole sale for under 200.00 brand new __________________ 95 admiral blue z(sold)/ / 93 ruby z(sold) 91 steel blue z/95 aqua z haibeck 510, 91 callaway 415 areobody #5