96-97 Engine Pics Requested

[abjamison]

OK here's the deal, I bought a 97 Lumina awhile back, heads started leaking and I was going to replace the gaskets, but it turns out the heads were in really bad shape and the block wasn't much better (apparently the car mileage had been rolled back or the person driving it before me liked to drag race...) So I spring for a remanufactured engine.

I had a fella put it in for me because I don't have the heavy lifting equipment. Well he obviously wasn't paying attention when he put it all back together. The wiring harness and vacuum hoses aren't where I think they should be, but to be honest I really don't remember what it looked like before. I wasn't expecting this to be a problem.

Anyway, there seems to be a vacuum leak somewhere in the intake, one of the vacuum lines or something I can't seem to track it down, so I'm going to break it down, not take off the manifold, but the top portion and try to straighten things out, check the top gaskets, retighten the manifold etc... Make sure he didn't forget anything else.

I'm requesting from anyone on these forums, some pictures of the top part of the engine, especially the firewall side so I can have some reference about how things are supposed to go back. It erks me when things aren't the way they are supposed to be.

BTW any advice on the leak is appreciated. It's misfiring on all cylinders at idle and low speeds, but few to no misfires on the highway. Makes me think it's vacuum related. Well that and I think I hear a leak, high pitched vacuum from the engine, but I just can't pinpoint it.

DTC spits out P0300 and P1406 "EGR Valve Pintle Position Circuit". EGR valve has been replaced to no avail. O2 sensor is working properly, MAP and MAF are working, clean air filter, plugs and wires are good.

Thanks in advance.

[jeffcoslacker]

I don't have a digital camera anymore, but I took a few pics of mine to illustrate other issues for other people, I'll see if I still have any that might be useful to you...

You can usually spray water, starting fluid, WD-40 or just about anything all around while the motor idles, when the liquid is drawn into the vacuum leak, the motor will react by picking up speed and idling better momentarily as the liquid sucks through and stops the airflow for a second....or if it's a massive leak like a line that's missing, it may bog down as it inhales a big snort of it directly...either way, you now know the area where the problem is, then you can pattern search to pinpoint it. Make sure you spray all over the top around the intake, as well as all vacuum lines and the vacuum resevoir, brake booster, etc...anything vacuum related...

Have you noticed any problems with climate control vent settings not working correctly?

[abjamison]

I've sprayed some WD40 around per your suggestion, on everything I could see relating to a vacuum, hoses, around the upper part of the intake, everything, there were no temporary changes in the way the engine runs at idle.

I haven't really driven it much because of the idle problem, just enough to know it's only missing at idle and not on the highway. That and the climate is quite nice right now so there's no need for air conditioning or heater. Tomorrow I'll try it out and see.

With what I've researched on the net if the EGR valve isn't operating correctly it can act like a bad vacuum leak. I have an Autotap system and it's displaying that the PCM isn't sending any requests to the EGR valve. The desired EGR position and actual EGR position isn't changing at all, whether or not the engine is warmed up and the engine is throttled up. There is a "EGR pintle position error" reading that is the only thing that changes in regards to the EGR valve.

Would it be necessary to update or replace my PCM because of a new engine? I've tried the procedure to relearn the idle calibration, but it didn't seem to help anything.

[abjamison]

Originally Posted by jeffcoslacker

Have you noticed any problems with climate control vent settings not working correctly?

All the climate settings seem to be working fine. This problem is really bugging me. Does anyone have any other ideas? If not I'll be forced to take it a dealership and my wallet will suffer the consequences

[jeffcoslacker]

My reference doesn't show PO1406 as a GM code...but it could be wrong.

Yes the EGR can create a lean misfire condition at idle. It sure sounds like there is some wiring that's not plugged in somewhere or something like that...I looked for some pics of wiring or vacuum circuits in the pics I took for people before of my engine, but all were of specific locations of stuff, not wide enough view to see how things should run....

It does sound like you are on the right track, the EGR is causing your performance problem, but what's causing the EGR problem? No update should be needed, the engine configuration is the same as before, with all the old parts, right?

It kinda sounds like it's just substituting a default EGR value because it's not getting any actual reading....I'd be following wires closely....I think you'll find something unplugged or pinched or something, sounds like...

[Blue Bowtie]

I hope you're not on dial-up:

[abjamison]

6mb DSL all the way hehe. Computers are my specialty and in that regard I do like the best available to me

THANKS Blue Bowtie for the pic, that shows just what I needed to know.
I knew things weren't where they were supposed to be. Hell some things I thought were right aren't. OK time to get out the wrenches and sledgehammer and do some work!

BTW

The specific code is just P1406, and searching on google brings up several posts with people having the same code, usually because the PCM isn't giving the EGR enough time to report it's actual position thereby triggering the code. There is actually a upgraded flash to give the PCM more time to accept the changes, however I am confident that is not my issue because those issues don't have any operating symptoms.

The reman engine has all the old parts from the old engine. The old engine was not having any problems like this. I reckon I'll take my volt meter to every single wire I can find and make sure everythings getting voltage and grounded.

Also I unplugged the EGR altogether and the idle problem still exists. Am I correct in assuming the EGR valve should stay 100% closed from a cold start just idling? I took off the EGR valve so I could watch the pintle and it doesn't move at all.

I agree that there must be something unplugged, a broken wire, or, less likely, perhaps another sensor has become faulty that is the root problem.

[abjamison]

Ok I don't like all caps, unless absolutely necessary so here goes.

HE PUT MY EGR VALVE ON BACKWARDS!!!!!!!! Which caused me to put on the new one BACKWARDS and take it off multiple times, each time putting back on backwards. ARGH!!!

Thanks to Blue Bowties picture that became very apparent I caught it out of the corner of my eye while looking at it. I went outside and turned it around and it has fixed the idling misfires on all cylinders. Granted now I have 2 cylinders misfiring, though not as regularly, but that doesn't worry me as much.

Thanks to you Jeff as well for trying to help me track down this ODD problem.

[jeffcoslacker]

That's one for the books...you should send that in to the Chilton's magazine feature called "Clunk Factor" where they describe the symptoms and eventual fix on oddball, didn't see that coming-type customer performance problems...

That's awesome. Glad it's fixed.

[jeffcoslacker]

BB, that bypass hose looks like it's ready to blow....

[Blue Bowtie]

Good eye. It feels fairly firm, and I think I replaced that about ten months ago when I flushed the system after 140K of neglect. It wasn't pretty. The overflow was black.