FC, Do you remember exactly where that 1st CAS shield section was grounded? If it was, that is, I have no reason to doubt Ted, even though it's strange to have that shield run in the harness if they didn't ground it...

I was thinking it might be "spliced" somewhere inside the harness, to an existing ground wire. I should just "get off my duff" and read that shield pigtail to ground, to verify one way or the other, eh?

 

Well, that pigtail is reading 1 ohm to ground, so that shield section at the CAS plug is in fact a "working" shield. Just don't know where it grounds, not that it's important now

Any more brilliant insights? Besides llamas in the gas tank, lol...

 

Hmmmm...I took a bunch of the apart in CZ a few months ago, and I never noticed a shielding.
Maybe I'm blind.


-Ted

 

That's all right, Ted, it's probably real easy to miss if they just spliced (or soldered it) it to a ground wire somewhere down the harness...

I wonder if one of my primary injectors is starting to die- They were just cleaned & flow tested during the rebuild (6,000 miles ago), but they're still 17 years old with 193,000 miles on 'em...I'll have to keep an eye on them, too, during a drive...Heck, how often do they go bad, though- I don't think I've heard of any just crapping out all of a sudden on the forum...

I sure hope this doesn't turn into another "Gnome" thread of 33 pages, lol...

 

You are correct Wayne it does in fact splice into an existing gound network. None of which physically touch the chasis until Waaay back down the line near the dashboard.

I THINK.. not sure, its been a couple of weeks since I rewired the bastered.

and there were SOooooooooooooo many ground wires I lost count (and track.. :S)

 

I'm pretty sure they are not made for premix.

I put even a brand new one in and they get clogged noticably in about a month for me. Meaning, that when the tank is down around 4 or 5 gallons, heavy acceleration at high RPM is impossable, looses power going up steep grades, and stalls on hard left turns.

So I replace it, problem goes away for a month . . .

 

That may be a plausible idea. you have to figure, they're not "Crapping out all of a sudden", it's failing at a high-load, known point. And it's doing it repeatably. Any chance you have a spare set laying around?

You know, normally I'd call for Wayne88N/A if there's a problem like this in the 2nd gen forum....

"We're boned!" - Bender

 

Actually, I think you have a o2 sensor going out so to speak. I've had that *hesitation* thing. On a long drive you'll be cruising along at the speed limit and you'll feel like your car all of a sudden gained five hundred lbs. It's not a jerking hesitation, but more subtle.

Are you sure you read your series four codes right? LED'S located in the cabin?

When this happens, I'd see the 02 code. By stepping on the pedal and speeding up then returning to the previous speed the code would go away and all would be well til maybe another fifty to one hundred miles.

A twenty buck Bosch fixed this. A permanent fix.

 

That's exactly why I call it a "mini" hesitation, Hailers, you've just described it perfectly...

I thought about the O2 sensor also, but it sure seems to be doing what it's supposed to be doing- and it's only about a year and a half old....

Yeah, now the CAS code I saw...Hmm...There have been instances when I would only get a single LED flash, because the item that triggered the code would "fix" itself quickly, and the ECU would start the code, but never finish it. The boost sensor code is famous for this (I get that damn code every time I romp on her, with diffrent boost sensors too-this all started with the wide open exhaust I put on her, so I figure the "abnormal" airflow is what's triggering it- she runs normally during that code, though)

Also got the O2 sensor code a couple of times about a week ago. Inspected the wiring and fund it chaffing on the tranny bellhousing. Don't know how far it chaffed, it didn't look like much, so I zip-tied it up off of there to keep it from doing any further damage.

I think the O2 codes were due to the lean conditions due to the pump going out...

Wonko- remember, this "mini' thing doesn't usually happen during high load, or romping (which is why I only marginally suspected the pump all that time). It happens during low load, low or high speed cruising, and most (if not all) of the times, a split second after the car goes over some form of bump in the road...

Tofu- That's what I worry about, the inlet sock getting clogged again because of the premix, it's not like I enjoy pulling that pump. I cut a small hole in the OEM's sock because of this ****, which may have been partly responsible for its demise, I dunno...

 

Are you sure you're not just feeling the closed loop? In my GTUs I can feel when it kicks on, the car will kind of pull, then decel, pull, decel, about one cycle a second, but once i nail it/etc it's just fine, it's kind of annoying at lower speeds going through town because the car actually feels like it's getting kicked from behind over and over again. This feeling was especially noticable just after replacing plugs/fuel filter/plug wires/etc. It always seems to be more noticable after the tune-up, then slowly gets more even.

 

****The boost sensor code is famous for this (I get that damn code every time I romp on her, wit******

Do you have the orifice in the boost line? I posted the part number last week.

 

Yeah, got the OEM orifice in the line near the UIM nipple, Hailers. Have also tried it without it, not much of a change. I'm going to keep an eye on the O2 again on the way to work today, if I suspect that something's screwy with the sensor, I'll go ahead and change it out, too. Hell, I'm at the point now where I don't mind throwing parts at it, as long as they're the 17 year old OEM parts, they're gonna be due sooner or later anyway...

No, Rat, it's not the closed loop, because she only started doing this a couple of months ago, and this is definetly a harsher "mini" hesitation than what you're talking about. She can be cruising along in closed loop just fine- until she hits a bump...

 

Well guys, it's not the O2 sensor- I disconnected it for a segment of the drive to work to run open loop all the time, didn't help anything. The sensor is doing it's job-she tries to run stoich in closed loop, I can tell. After I got on the freeway, she'll try to hit stoich, and then slowly fall to 0 to .1v (WAY lean). I drove her down 30 miles of freeway at 65 mph reading .1 tops. Not good...She's starving for fuel during cruise, yet goes back to .8v at idle (or neutral), which is good...

So it wasn't the pump...Filters have been changed, that means it's time to zero in on the FPR...Pulled the vac hose off when I got to work, no fuel in the hose, so the diaphragm isn't busted. If I have time I'm going to take it off and "play with it". Probably all clogged up with premix and stuck open, lol...

Thanks for the help and ideas, guys

 

dirty injectors?

 

If it's starving for fuel at high-load situations, couldn't that point to some sort of AFM problem? Maybe it's sticking sometimes?

 

AFM is reading great from the ECU the whole drive, coopster, everything's in specs with that bad boy...

Injectors just cleaned & flow tested during the rebuild, 6,000 miles ago, Rat...I haven't totally ruled them out yet, though, I'm gonna see about this FPR next...

 

Whuah???
It sounds like you're not running TC-W3 stuff.
I've used Valvoline Multi-Use pre-mix for years now.
I've even had the car sit in the Vegas desert for 2 years.
I've never had a problem of the car "clogging" at any point.


-Ted

 

WTF is this trend of pointing fingers at the AFM nowadays?!??!?


-Ted

 

I tried different TCW3 rated oils.

I was using the Amsoil 100:1 stuff before
Then when I swapped out fuel pumps and filters, I swapped to that Quicksilver stuff
Now I'm using Penzoil.

Do you think my fuel pump, or the voltage to the fuel pump, may be to blame?

 

I've also never had problem with clogging of the intank sock while running premix, even down to a ratio of 50:1.

 

How do you even know it's getting clogged?
Are you running a fuel pressure gauge?
Pre-mix will tend to "color" the filters, but that doesn't mean it's clogged...


-Ted

 

Well, that's good to hear I was always concerned about that...

Well, took the FPR off here at work, cleaned it out (was pretty clean in there to begin with), beat it on the desk a couple of times, verified it's getting vac from the hose...See what happens on the drive home tonight...If this sucker isn't it I'm going to start leaning towards the ECU & injector harness (bad harness might make some sense considering bumps affect this sucker), although my harness has always been in good shape so far, I unwrapped & inspected a good portion of it during the rebuild, then rewrapped it...Not the part up on the engine, though, for the injectors...Didn't want to break any of that hard, stiff wiring, lol...

The saga continues...

 

Wayne I've been looking for a solution to this issue. I replaced the FPR with two injectors when this first started. I'd be interested to find out whether the fuel pressure regulator could cause this problem.

 

You've got the same thing going on???

And what do you mean, "I replaced the FPR with two injectors"???

 

Boys and girls, I think we have a winner- she drove great on the way home, only stumbling 4 or 5 times, on the really big freeway bumps, and she ran at stoich the entire trip. Whacking the FPR must have done something, lol....Now to get a new one before she lapses into her old ways again...

And Hailers, I was thinking of you when I played around a bit while the meter was on the O2 sensor- I can't get her to run closed loop at all in 4th gear, which means your 5th switch also has that function to deal with