part identification

[mcma2244]

Hey I am new to this forum and was looking for a little help. I have a 1990 ZR1 and the rubber part I circled in green keeps popping off. I was wondering if anyone knew what could be causing this or if there is a replacement part. It seems to be idling quite high when I first start it, or it begins to stall. I had it attached to a diagnostic computer and it said one side was running rich and the other was lean. The Chevy dealer in town was stumped. Thanks

file:///Users/Home/Desktop/Picture%20clipping%201.jpg

[Kevin]

looks like the map sensor hose. common problem, it can be cured by ziptying it to the MAP sensor and then holding the key just a bit longer then normal when starting the car

[mike100]

well, it looks like to me the rubber PCV elbow is circled. Those things can fit the pcv valves kind of loosely and leak all kind of extra air to the throttle body (high idle).

the high idle could also be a hose popped off under the plenum (somewhat common). Will it idle below 1200 rpms when it is warmed up?

btw, the LT5 start-up does rev a little high even when all is well. should idle down to 800 rpms within a short period of time.

[Pete]

Looks to be the feul regulator vacuum hose.
If it keeps popping out,look to see if regulator is leaking,start car and pull the hose off see if feul is coming out,if so you need to replace regulator.

Pete

[mcma2244]

Hey thanks everyone for the info, Ill try your recommendations and get back to you tomorrow when I pick it up from the dealer.

@Mike: It will sometimes idle below 1200 but will randomly shoot up past 1500rpm then will idle down to a stall.

[Kevin]

also, never take these cars to a dealer...you'll end up paying a lot for nothing

[tccrab]

well, it looks like to me the rubber PCV elbow is circled. Those things can fit the pcv valves kind of loosely and leak all kind of extra air to the throttle body (high idle).

the high idle could also be a hose popped off under the plenum (somewhat common). Will it idle below 1200 rpms when it is warmed up?

btw, the LT5 start-up does rev a little high even when all is well. should idle down to 800 rpms within a short period of time.


I agree.
The part circled appears to be the PCV connector.
Kurt White sells 'em:
Just the upper connector thingy:
http://www.whiteracingproducts.com/index.php?main_page=product_info&cPath=298_303&products_id=1884&zenid=0680db7b4e3f6cdc102026bebacdc8e2
Both lower hose and upper connector:
http://www.whiteracingproducts.com/index.php?main_page=product_info&cPath=10_67&products_id=1012&zenid=0680db7b4e3f6cdc102026bebacdc8e2

TomC
'Crabs

[Pete]

The PCV hoses are a common issue on our Z's.
I just figured just looking at it one would know it's PCV's,i guess never assume anything.
This is why i suggested the feul line since that is also in the circle and a bad regulator will also have bad idle and stall motor.

Pete

[A26B]

It could be a leaking injector, considering the rich condition on one bank.

One of the tuning gurus could answer far better than me, but would a leaking injector cause the ECM to consider TPS at idle & command the IAC to increase idle air to compensate for the rich O2 signal on one bank?

I don't see it causing the PVC Connector to blow off, which may or may not be related at all.

We do see a lot of bad, original injectors leaking in the 90-92 models.

[PhillipsLT5]

Jerry, he is in OK, close to you?
PCV hose probably shot like all the rest

[A26B]

Jerry, he is in OK, close to you?
PCV hose probably shot like all the rest

You are right, he is from OK, but I don't know where, or his name. Maybe some profile info?

[mcma2244]

Sorry,

My name is Tim, and I live in Altus, OK. Just got it back from the dealership. They changed the oil but were unable to find a ECU (from the service bulletin from Feb 94) or the PVC part. Thanks Tom C for finding that part huge help! Might start looking into an aftermarket ECU. My Z is all stock I was wondering anyone has some recommendations.

I will test for a leaky injector this weekend and let you all know. Thanks so much for all the help and advice it is greatly appreciated.

[PhillipsLT5]

Get with Jerry, A26B, he can help you more than you know
Better check the oil after 24 hr shut down, I doubt they know the capacity
You may be 3 to 4 qts low if they think it is a Small Block Chev

[tccrab]

Sorry,

My name is Tim, and I live in Altus, OK. Just got it back from the dealership. They changed the oil but were unable to find a ECU (from the service bulletin from Feb 94) or the PVC part. Thanks Tom C for finding that part huge help! Might start looking into an aftermarket ECU. My Z is all stock I was wondering anyone has some recommendations.

I will test for a leaky injector this weekend and let you all know. Thanks so much for all the help and advice it is greatly appreciated.

Tim:

Welcome to the Brotherhood!!!

PCV tube, been there done that. Glad to be of help.
Pretty much the only game in town as far as that part.
Another great resource for "stuff" that you might need is Jerry's Gaskets, you'll find him here in this thread already.
(I suspect he'll be knocking on your door fairly soon, won't ya, Jerry??)

As far as the ECU, do you mean the ECM that lives under hood next to the power brake booster?
If so, this part is going to be a little difficult to locate.
Not quite "Un-Obtanium" but the few that are out there tend to be pretty gosh darn expensive.
I would advise that you make absolutely gosh darn sure you need one before you buy one.
There have been quite a few threads about these over the last few years, I'm pretty sure there's info on where to get one rebuilt without breaking the piggy bank or wiping out your 401k.

TomC
'Crabs

[FU]

I "think" that Marc Haibeck know's or has a ECM rebuilder.

[tomtom72]

Hey I am new to this forum and was looking for a little help. I have a 1990 ZR1 and the rubber part I circled in green keeps popping off. I was wondering if anyone knew what could be causing this or if there is a replacement part. It seems to be idling quite high when I first start it, or it begins to stall. I had it attached to a diagnostic computer and it said one side was running rich and the other was lean. The Chevy dealer in town was stumped. Thanks

file:///Users/Home/Desktop/Picture%20clipping%201.jpg

That would be the fuel profile that a scan tool would present if there were more than one bad primary injector and the scan was taken during "closed loop" operation. The shorted injector coils prevent that injector from firing, hence on that bank the O2 sensor would report a lean condition to the ECM. The ECM would in tern try to lengthen the injector pulse and that is what the scan tool is actually showing. I know this sounds like I'm smoking something great....I'm not. You have to remember when reading scan tool data that the tool is getting it's data straight from the ECM. Therefore one will also "see" what the ECM is doing to correct a reported situation, not the situation that is causing the ECM's correction. For that you have to look at the O2 voltage and cross counts and BLM's and Int #'s ( and go smell the exhaust. If your eyes water, she's dead lean. Bad injectors. ) It's a bit counter intuitive until you pull the plugs and find the ones that look new = no fuel to that hole/ shorted injector.

Why were they looking for an ECM? You are sure that they were not looking for the updated EEPROM code AYBK that was listed in a TSB as a cure for idle fluctuation and a host of other things? The EEPROM's code AYBK are NLA.

Okay enough bull chips.....sounds like you need to replace your OEM injectors because the ethanol in our gas killed them. The early injector coils were not resistant to ethanol as it wasn't in the gas back then. The F connector will pop off, be a very loose fit and otherwise make your life miserable.....just buy the samco set up and remember to buy small ideal clamps for the whole thing.

:cheers:
Tom

[Z51JEFF]

One easy fix for loose PCV connections. I wrapped thread around the tops of the valve to increase the diameter and the thread surface created some friction to help hold them in place.I sealed the thread with epoxy to keep it together.This was the only thing I could think of as far as creating a seal between the valves and the fitting.Another thing i thought of was to stack O rings around the valves.Id like to find a new fitting,but not for $50.

[mgbrv8]

Dose anyone have a old replaced #9 Connector, PCV Valve Upper rubber connector? I want to make a CAD drawing of it and make a mold so we dont have to pay $50 bucks for a old new part. I see lots of these going bad in the future and I prefer not to line greedy pockets.

[tomtom72]

Dose anyone have a old replaced #9 Connector, PCV Valve Upper rubber connector? I want to make a CAD drawing of it and make a mold so we dont have to pay $50 bucks for a old new part. I see lots of these going bad in the future and I prefer not to line greedy pockets.

I have an intact OEM PCV set (top and bottom) would you like me to send them in aid of this effort? They are used as they were on my 90 before I bought the Samco stuff. They are not cracked or distorted...I replaced them purely to avoid the bottom holder splitting from age as they're prone to do. I think if I look thru my spare parts bin I proly have a NOS OEM F-connector I could send also so you can compare new & old for dimensional stability.

:cheers:
Tom

[mgbrv8]

Sure, I will Pm you my address

Dave

[bldavis11]

Get with Jerry, A26B, he can help you more than you know
Better check the oil after 24 hr shut down, I doubt they know the capacity
You may be 3 to 4 qts low if they think it is a Small Block Chev


Tim,

This is some of the best advice you've been given from this thread. You NEED TO CHECK YOUR OIL LEVEL. The dealers are a bunch of paste eaters when it comes to LT5s.

I would hold off on pulling the trigger on an ECM as well. There are a bunch of cheaper and easier things to run to ground before you go that route.

Welcome aboard!
Ben


:saluting:

[jrd1990zr1]

I have an intact OEM PCV set (top and bottom) would you like me to send them in aid of this effort? They are used as they were on my 90 before I bought the Samco stuff. They are not cracked or distorted...I replaced them purely to avoid the bottom holder splitting from age as they're prone to do. I think if I look thru my spare parts bin I proly have a NOS OEM F-connector I could send also so you can compare new & old for dimensional stability.

:cheers:
Tom

Tom,

If you can't locate the F-connector, I have one.

John