Got a few codes.

[riselly1]

Hello, my name is rick and I am new to the ZR-1 LT5 world. Let me just say i was a little wairy when i purchased my ZR1 back in march but after the first drive i was hooked and do not miss my 996 at all, this thing just rocks !! http://zr1.net/forum/images/smilies/eusa_dance.gif

Anyways, I have put a little over 2K miles with no issues but just yesterday my Z seems to be feeling a little sick. It sat for about a week and when i started it i noticed a fluctuating idle that looks like its about to quit but the car saves it, sometimes it does stall but i can start it right back with no issues. heres the list of codes i pulled.......

12
13: Left oxygen sensor open
14: coolant sensor high temp
21: throttle position sensor high TPS
22: throttle position sensor low TPS
23: manifold air temperature MAT temp low
41: cylinder select error
42: electronic spark timing EST system error
43: Electronic spark control ESC system error
34: mass air flow sensor low MAP
33: mass air flow sensor high MAP
32: EGR system failure ???
31: Cam sensor missing or too many pulses
12

http://zr1.net/forum/images/smilies/icon_cry.gif

As i said before the only thing differently was it sat for a little longer than usual and HAD to put some of that cheap "Westar" gas instead of SHELL. Also when i purchased the car it came with the secondary port throttle vacuum unplugled and the car refused to go past 140. I have plugged it in since but have not done another fast run so idk.


Any advise fellas??

[Kevin]

I've never seen that many codes in even the worst maintained car. Reset the ecm, go for a drive and see what comes back

[G8nightman]

Second Kevin's post.


Sent from my iPhone using ZR-1 Net Registry (https://siteowners.tapatalk.com/byo/displayAndDownloadByoApp?rid=90383)

[gbrtng]

Looks like your ECM pooped the bed - try to locate a loaner replacement to swap in.

[A26B]

I think you may have a lot of stored codes, agreeing with Kevin. Disconnect the battery for a couple of minutes, drive it for awhile, then check to see what new codes are set, if any.

FYI, if you have multiple codes, always start diagnostics with the numerically lowest code first. Resolving the numerically lowest code first will most likely take care of the others as well.

[riselly1]

Hey ladies I took a little longer to respond than expected. I tried a few combinations between "good" and bad gas, resetting the computer before, during and after and this is what I currently have:

Good news; the codes are gone. I now have code 44 and 54 for the tire pressure monitor. And service engine blinks 12 only

Bad news; while idle is steady during hard breaking the car stalls or wants to quit with mild braking. Power isn't always there, and I feel like it back fires a little when off the gas. Tried with power key on or off.

Sounds like a vacuum doesn't it??

[We Gone]

Congrats on your ZR-1 I hope that you get everything taken care of.
Just out of curiosity what year?

[riselly1]

Hey thanks ! Its a 91 burgundy with 34k miles on her.

[We Gone]

IAC may need to be cleaned, You need to put it on a scanner it could also be a lazy O2 sensor or TPS. A scanner would point you in the right direction.

[BigJohn]

mouse nest?

[riselly1]

I'm still on the works trying to get an obd1 scanner. My local auto parts say they no longer scan vehicles. ?? 🤔

Anyway, I cleaned the IAC, it had some gunk on it but the bad news is the seal came apart when I sprayed it. It just desintegrated, how bad do you think that's gonna mess me up??

Also I unplugged the brake booster to rule out a diaphragm leak, but the engines behaves the same, so.... NEXT !

[Racinfan83]

Sounds like you have vacuum leak/s to me. MAP sensor connection was my worst one...

[riselly1]

Hey ladies, taking the plenum off tomorrow morning. Did a vacuum test and it doesn't hold ****. Once warmed it's not as bad, som I'm thinking something is expanding and maybe sealing off the leak??

Break booster and secondary pump hold vacuum like champs. I will follow some write up I found here at the registry.

Any words of wisdom?

[XfireZ51]

Before pulling the plenum, pull the BATT - cable and then open the ECM. Pop the prom and then re-seat it until the tabs on either end snap properly and snugly.
See what happens.
If the secondaries are not holding vacuum, that needs to be addressed.

[mike100]

There are 3 or 4 common places under plenum where vacuum leaks and also the map sensor hose is a common failure that causes erratic driveability (many times with no codes associated with it).

Will it idle below 1000 rpm when it is warmed up?

[riselly1]

Tried the battery with no luck and no codes either. Plenum came off !!

First order of business; I found 4 leaks , sweated like a pig and got a sore back. Leaks are as follow:

1) 2 x secondary vacuum canisters; are there guys supposed to hold any vacuum at all, b/c air just whistles right out and I can see a plate moving back and forth as I applied vacuum on both?
2) the T section between the check valve and reservoir; funny thing is it holds vacuum coming from the side plenum line, but when i tried the line coming form the secondary pump it looses all vacuum in 10 s. ** secondary reservoir holds perfect vacuum.
3) driver's side line going into the secondary vacuum solenoid. it just whistles and i loose vacuum in 10s. the right side line is good.

I included a pic highlighting the leaks in blue. Check it out and let me know if something doesn't make sense before I start hunting for parts.

[Top Toy]

Now would be a great time to get rid of your secondaries. Very common mod for LT5's. Eliminates a lot of the headaches you're wrestling with with no loss of driveability. Lots of info on this forum re how to do it.

Sent from my XT1254 using ZR-1 Net Registry mobile app (http://r.tapatalk.com/byo?rid=90383)

[Kevin]

Now would be a great time to get rid of your secondaries. Very common mod for LT5's. Eliminates a lot of the headaches you're wrestling with with no loss of driveability. Lots of info on this forum re how to do it.

Sent from my XT1254 using ZR-1 Net Registry mobile app (http://r.tapatalk.com/byo?rid=90383)

I've been kicking around this idea and if I could find a stock cube non-ported car to drive before I do I probably would.

[GOLDCYLON]

I've been kicking around this idea and if I could find a stock cube non-ported car to drive before I do I probably would.

Just do it Kevin and have Dom retune it for ya it. Worked great for me

[riselly1]

Hey guys finally had the time to put everything back this morning. Changed both secondarie canisters and my check valve wasn't working either. The entire system holds 15+ of vacuum now 👏👏👏

Problem: after say 30s-1min of running white smoke/fog comes from under plenum on the passenger side only. She also did it before taking plenum off. I don't like smoke so I didn't play with it anymore, any suggestions???

I also noticed viscous oil deposits on the long piece where the injector housing connects to the block.