Full engine Power light

[SteveCanyon]

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?

[Kevin]

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

[SteveCanyon]

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?

[Kevin]

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

[SteveCanyon]

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?

[Kevin]

The injectors definitely need done at that point. http://fuelinjectorconnection.com/shop/index.php?_a=category&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

[SteveCanyon]

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

[SteveCanyon]

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

[Funracer]

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!

[Funracer]

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.

[Hib Halverson]

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?

I think rather than beginning the process by thowing parts at the problem (ie: arbitrarily replacing the fuel pumps), I'd get a copy of the factory service manual and run the tests and other diagnostic procedures for those two codes.

Why do I suggest that?

Well, 1) because it's how service techs go about solving problems and 2) you've got a strange situation with DTC 55 and 65 setting together. DTC55 is for lean exhaust when the secondaries are commanded open. DTC65 is for rich exhaust on the right bank.

Let's think for a minute. To set DTC55 the system has to be in closed loop and PE, the secondary pump has to be commanded on and either the right or left O2S has to indicate a lean exhaust for at least 2-sec.

But...DTC65 sets when the system is in closed loop, the throttle is less then 2.7% or more than 20% TPS for 30 seconds or more and the right bank runs rich for 30 seconds or more.

Seems strange to have the engine lean and rich at the same time.

Indeed, this could be a pump problem, but it also could be something else. Before I'd spend the bucks on a pump assembly and go to the trouble to change them, I'd run some tests out of the FSM to verify that the secondary pump is the problem.

[SteveCanyon]

Hib, thanks for the insight. I don't have the FSM yet since I just got my car. I know the injectors need to be done so will go ahead and do those, and the pumps were cheap enough to just do them at the same time.

The DTC 55 code has me puzzled if that only happens when the secondaries are commanded open, since when my power key is in full power the light does not stay on. I am 99% sure my car has the stock chip, but maybe the original owner put in a chip that keeps the secondaries open all the time? If a chip is put in to keep them on, does the light stay on all the time on the dash though?

[SteveCanyon]

Here is the chip in my car, have no way knowing if it is stock or from someone else though.

[Kevin]

Hib, thanks for the insight. I don't have the FSM yet since I just got my car. I know the injectors need to be done so will go ahead and do those, and the pumps were cheap enough to just do them at the same time.

The DTC 55 code has me puzzled if that only happens when the secondaries are commanded open, since when my power key is in full power the light does not stay on. I am 99% sure my car has the stock chip, but maybe the original owner put in a chip that keeps the secondaries open all the time? If a chip is put in to keep them on, does the light stay on all the time on the dash though?

the power light is a result of a bad switch, same problem I had for a bit before I took it apart

[SteveCanyon]

So is the car going to full power with the switch in full power mode even without the full power light coming on?

[SteveCanyon]

Ok, Paul W. sent me a PM with some info. I had not tried clearing out the codes, so disconnected the battery for about half an hour. Just drove the car, still no full power with the switch. However, when I manually hold it against the stops and the light illuminates, I am getting full power when I punch it. Drove it for a while and came home, checked the codes and none appeared except the code 12. So, going to hold off on the fuel system for now. So, in the end it was the switch. I am getting a Hailbeck chip so may just have him fix it in there instead of pulling the switch out for now.

[Franke]

Steve, that AUAH is the stock original chip. Marc H will be able to get you the upgraded GM chip which I believe is AYBK3 and he adds his goodies to it as well. Go to his site which is "ZR1 specialist" and check out the new chip advantages over the stock one. I have the upgraded chip from Marc and it works great.

[Kevin]

Ok, Paul W. sent me a PM with some info. I had not tried clearing out the codes, so disconnected the battery for about half an hour. Just drove the car, still no full power with the switch. However, when I manually hold it against the stops and the light illuminates, I am getting full power when I punch it. Drove it for a while and came home, checked the codes and none appeared except the code 12. So, going to hold off on the fuel system for now. So, in the end it was the switch. I am getting a Hailbeck chip so may just have him fix it in there instead of pulling the switch out for now.

on a 90 the chip won't fix the switch. on the 91+ cars the car defaults to off when you start the car, on the 90 the car will start with what ever position the key is on.

[SteveCanyon]

Ah, OK. Looks like I am pulling the switch out today then.

[Paul Workman]

I found that I left the switch in FULL POWER all the time anyway (on my 90). And, as I said the REAL reason for it in the first place had to do with sound abatement - that "valet key" was a smoke screen that came out of the marketing department (specifically detailed in Young's book "HEART OF THE BEAST")

Of course, if you delete the Secondary Port Throttles* (SPT), then on a 90 it is recommended that you assure the switch is ALWAYS turned to FULL POWER mode or else one of the injectors will be cut off and resulting in a dangerously LEAN condition, should the switch not be in FULL POWER either by accidentally turning it off, OR if the switch itself becomes intermittent.[-X (For engine safety sake, I soldered a jumper wire across the switch so that intermittent connection would never happen. It's easy to install the jumper, and can easily be reversed if desired.)

* This is causing your thread to veer off the path, but just FYI for now, unless your car already has been modded for secondary delete. (That is doubtful, or you'd be having a lot of trouble getting it to run anywhere close to 5000 rpm on half the fuel - as the fueling is split between both injectors in FULL POWER mode.)

[SteveCanyon]

OK, pulled the switch out and fixed it, took about an hour and everything is working now. Now on to the next fix as I am getting a misfire from one of the injectors so will tackle that as soon as I get them in. Also waiting for my OBX cat back and Hailbeck chip to come in, as well as my A-Molds. Money pit already!

[NVMYRC51]

Man I am glad I found this. I just noticed my full power light not being on all the time and I never turn it off. Now I can rebuild it.

Craig,

[PhillipsLT5]

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

Get the new, not rebuilt injectors

[A26B]

Get the new, not rebuilt injectors

;)That's all we carry....New

[Kevin]

hope my thread was able to help you guys.

[SteveCanyon]

hope my thread was able to help you guys.

It did, I actually had to put a thin shim behind the outside connector to get a good solid contact.

[PhillipsLT5]

;)That's all we carry....New

Jerry is always on top of it

[Dynomite]

So is the car going to full power with the switch in full power mode even without the full power light coming on?

I think not but will ask the same question here ;)

hope my thread was able to help you guys.

Thanks Kevin for the thread on repairing the Full Power Switch (now in -Solutions-) :thumbsup:

Jerry is always on top of it

Yes.....Jerry sets the standards in parts quality, packaging, and Delivery Speed (Response) :thumbsup: :thumbsup:

[Paul Workman]

Man I am glad I found this. I just noticed my full power light not being on all the time and I never turn it off. Now I can rebuild it.

Craig,

Although it may well be a funky switch (on the 90 can we assume?), but know too that if there is a fault in progress, the ECM will shut the SPTs off. I'd check out the switch, for sure, but the switch may or may not be the real issue.

Just sayin...

So is the car going to full power with the switch in full power mode even without the full power light coming on?

If the bulb in the DTC is burned out, then yes the secondaries will continue to operate: all is well. Otherwise, the secondaries are not opening, and 5500 is about all you can squeeze out of the motor.

Clear as mud? :cheers:

[Dynomite]

If the bulb in the DTC is burned out, then yes the secondaries will continue to operate: all is well. Otherwise, the secondaries are not opening, and 5500 is about all you can squeeze out of the motor.

Clear as mud? :cheers:

Paul .....if you have a bad switch I assume the light will still come on with everything else with switch on. How difficult to change bulbs?

What is the bulb size/number?

[Paul Workman]

Paul .....if you have a bad switch I assume the light will still come on with everything else with switch on....*

:icon_scra Uh...Say what??

Switch = no workee, da SPTs = no workee too. (Also, light = not ON.)

On stock setup, SPTs not running is disappointing.

With SPTs deleted mod, if NOT in FULL ENGINE POWER mode, secondary injectors are NOT running and fuel is cut in half = VERY lean condition; dangerous, in fact. (The bulb working on SPT delete modded cars is critically important.)

I dunno what the bulb size is, but I believe I saw it listed in the FSM, no?

[Dynomite]

:icon_scra Uh...Say what??

Switch = no workee, da SPTs = no workee too. (Also, light = not ON.)



Da.......I am better with a wrench in my hand than a mouse and laptop :sign10:

I meant to say.....there is the power switch and the ignition switch. When you first turn on ignition switch....ALL the ZR-1 Diagnostic Light Panel lights are on including the Full Power light IF the Full Power Switch is on and working properly :D


With SPTs deleted mod, if NOT in FULL ENGINE POWER mode, secondary injectors are NOT running and fuel is cut in half = VERY lean condition; dangerous, in fact. (The bulb working on SPT delete modded cars is critically important.)


Great point there Paul :thumbsup:
On a 91' I have SANS secondaries and Marc Haibeck Chip which takes care of everything. But then the Full Power mode does not show up as a lighted sign on the ZR-1 Diagnostic Light Panel but green light by Full Power Switch on 91' is always green.....(I think again but will have to look at that also) :D

hope my thread was able to help you guys.

Kevin........Thanks for your Full Power Switch Restoration Thread again......just restored two Full Power Switches on 1990s today. Found a channel lock pliers opened up to the diameter of the Full Power Switch Locking Ring on the back side of the Bezel is the easiest way to twist the Locking Ring so the Full Power Switch can be removed as you suggested :thumbsup: