Black51

Do you have an aftermarket boost gauge hooked up? You can tell if there is a vacuum leak or something is wrong under boost just by looking at it with the car running. That would be almost a sure sign of a vacuum problem. That, or you have dead cylinders. I've had both happen before.

You mentioned you need plug wires. How about the rotor? What shape is it in? Not too hard to check. Also the coil comes to mind. I've had issues where the car would rev up fine and idle fine under no driving load, but when driving hard, the car would fall on its face. I wasn't getting a good spark on one or more cylinders under boost. It's so east to check that stuff, don't not do it if you haven't.

Also, it would be a good thing to install a wideband to check your mixture, and make sure the engine isn't running way lean or pig rich. My bet is it's not a mixture thing, but still a good thing to have on the car at any time.

Does the car have a cat? Is it original? Now that it's suspected that this is something of a larger issue, I would start considering pulling the crossover and checking to make sure the inner walls have collapsed. While you're in there is when I would check the WG too. But if the car makes no power at all off boost, then I doubt the WG is the problem, or at least the only single problem.

dunl

Well, she has sat all winter, with a little run around the block to see if the couple of small vacuum leaks I found were fixing anything. Nothing.

So, I decided yesterday to get back to work on it, and knew it needed a little oil. Couldn't crack the oil cap, until I really applied pressure to it.

Turned it over and the bottom of the cap looked like Bailey's Irish Cream.

I only spent $500 out of pocket buying it, right?

Mighty Shilling

Don't be too concerned if the dipstick doesn't have that crap on it, or your coolant reservoir isn't full of milkshake. Condensation is known to adhere to that cap resulting in that, take it for a spin, get it nice and hot, check again.

dunl

Thanks for that advice. The milkshake wasn'tn the dipstick, so the wife and I took it for a drive and got it nice and hot. No coolant loss either.

Anyway, seems fine, as I was thinking maybe we were looking at a head gasket here.

So.....good news, no head gasket issue. Bad news, still bogs down under acceleration, like it is flooding until I let off a bit, and I need to figure that out.

Mighty Shilling

So here's a thought. A while back I was having AFM issues. I would be drivin along normally just fine and then when I would boost it would start bucking and backfiring and I couldn't really drive it. Essentially what happened was the AFM door would stick and confuse the car. I had to replace the AFM. Find someone local and borrow their AFM. If it fixes it, blam. If not then we know what it isn't. I feel like it may be electrical.

dunl

That sounds like what I was thinking. Maybe the mix of the fuel to air ratio isn't correct.

I mean....back off the accelerator and the car speeds up?

There's a guy around here locally with some parts....I'll contact him.

Mighty Shilling

since I've started tuning my car (well, Rogue started tuning my car, I'll give credit where it's due) I've learned a ton about how much effect air/fuel mixture has on how your car will run, and the symptoms of too rich, etc. I mean, if the air metering tool you have ain't right, it WILL screw it up something fierce.

another thing I've noticed is when my AFM was bad and it was sticking, when I'd manually open the door with a screwdriver or something, it would squeak. we took a known good one, and it didn't squeak. I cleaned the known good one, (with brake cleaner. DO NOT DO THIS!) and washed away all the lube by accident and the car started having issues again. the "clean" AFM started squeaking. put ANOTHER known good one and didn't clean it, it didn't squeak. bam. problem solved.

dunl

I noticed mine seemed stiff. Perhaps I will try to lubricate, NOT CLEAN, it....thanks for that. First thing I would have grabbed would probably be the Brake Kleen.....

Black51

If you are ever in Edmonton, let me know. I'll help you diagnose the problem.

Tom M'Guinn

How are the cap, rotor, plugs, coil, and wires? Bad ignition shows up first under load -- it's common for turbo cars to bog down just when the try to make boost, as the cylinder pressure overwhelms a very weak spark. Frankly, it could be lots and lots of things, but if the car has been neglected, you will not be wasting time or money addressing the basic maintenance first -- since you'll want to get to that eventually anyway.

Mighty Shilling

Yes. Spark is important too. One thing I learned, close the spark plug gap a little and it'll help with a stronger spark under boost.