Full engine Power light & Check Engine light
 

When I turn the valet key to full power the full engine power light briefly illuminates then goes out. Is it supposed to be on all the time? It will come on and stay if I move the key to the stop and hold it, but if I release that pressure the light goes out. Car does not seem to be making full power. The first time I got on it the rpm stopped climbing and stopped at about 5.5K RPM and then got the Check Engine light.

Second, I hooked up my scanner and got codes 12, 55 & 65. Is code 55 Fuel Monitor lean, and code 65 Right O2 Sensor? If so, what should my trouble shooting process be from here?

Re: Full engine Power light
 

code 55 is Fuel Monitor Lean

65 is Right Oxygen Sensor (Right Bank Rich)

the light should stay on all the time, and since you have a 90 it's a very simple fix to rebuild the power key. And you're in luck because I already did a write up on how to fix it http://www.zr1.net/forum/showthread.php?t=15255

Re: Full engine Power light
 

Kevin, thanks and that will give me a start on that problem. Any other ideas of what is driving the 55/65 codes? Does the right O2 sensor need to be replaced? Would a faulty secondary fuel pump cause one or both of the above codes? Would low fuel pressure from the secondary pump cause the full engine power light not to illuminate even with the key in the full power position?

Re: Full engine Power light
 

With code 55 and the cutting out over 5500 I'm thinking you have a bad secondary pump, I'd replace both pumps with 454 suburban pumps. 65 could be leaking injectors. 12 is just a check code, nothing to worry about there

Re: Full engine Power light
 

Thanks, sounds like time to do the fuel pumps and injectors, my car is a bone stock 90 with 16K miles and pretty sure the injectors have never been done. Both pumps are the same correct?

Re: Full engine Power light
 

The injectors definitely need done at that point. http://fuelinjectorconnection.com/sh...gory&cat_id=15 is who'd i'd go with, I believe they're a registry sponsor, which you should join by the way, great organization. And they offer a life time warranty

Re: Full engine Power light
 

I ordered 2 of the pumps from Rock Auto and will order the injectors from Jerry's with the gaskets.

Re: Full engine Power light
 

About how long does it take to change out both fuel pumps?

Re: Full engine Power light
 

Easy to get the pumps out. Just lift and turn slowly and it will come out.
Try to pay attention to which way you turn and lean the pump assembly when you
take it out. The install is the reverse and can be frustrating if you have not done it before.

Actually swapping the pumps is straight forward. My only suggestion is to not reuse the plastic
(or nylon whatever they are made of) ratchet clips on the fuel lines. They are apparently single use
clips. I reused them and had to pull the pumps again almost immediately to repair a slipped fuel line.
Just use small stainless screw clamps.

How long? First time 2-3 hours if you go slow. Also put some masking tape on the forward edge of the painted gas cap well. When you pull the pumps you can scrape the paint in that area. Don't ask me how
I know that. Good luck!

Re: Full engine Power light
 

Also I forgot to mention. As others have said careful with the rubber bib around the fuel fill mouth.
Use WD40 or something to lube it and stretch slowly. They rip easily (don't ask
me how I know this either) and are hard to find if you need a new one.