'96 850 GLT Surging

[j_cd]

Watched your video. That Snap On Solus is a cool scanner. Kinda hard to read on video though, and I'm not sure exactly which readings to look for.

You might as well try changing the IACV at this point. I'm also wondering if it could be an exhaust leak, but it does sound more like intake.

Have you pulled the intake manifold off yet? It might be a good idea to see how the PCV (crankcase vent system) is doing. How does the turbo air intake look? It's between the MAF and Turbo. Are the plastic lines at the PTC Heater (just before the turbo intake) still attached? Is there oil caked all over there?

[bensr20det]

Its funny you should mention an exhaust leak be cause yesterday I did notice my muffler we hanging crooked because one of my hangers broke. Could an exhaust leak cause the system to run rich? I just went and started it back up after letting it sit for a few hours and here is what happened. It initially surged twice, starting at 2000 RPM down to 1500. Back to 2000 and then 1500 again. From there it slowly worked its way back down to 8 or 900. There it stabilized and started to idle ruff and black smoke. But it wasn't surging like it was. Then I gave it some gas and took it up to about 3000 RPM and let off. It did the same surge twice and work it's way back down around 800 where it stayed ruff. Any ideas with that info?

[bensr20det]

Oh and this is a non-turbo. I do have a line that runs from the PCV to the plastic elbow between the MAF and throttle body. I noticed yesterday that when it would surge high smoke would come out of that connection. I removed it and took a look. There was a little oil in there but I wouldn't say it was caked in there by any means, not like it was when I replaced it last year. It was wet oil if anything. I did wrap some tape around that connector and reinstalled it to seal up and leaks there but that didn't make a difference. I don't mind taking off the PCV again and checking it out but will they clog in less than a year or are we thinking there is an air leak there?

[j_cd]

Its funny you should mention an exhaust leak be cause yesterday I did notice my muffler we hanging crooked because one of my hangers broke. Could an exhaust leak cause the system to run rich? I just went and started it back up after letting it sit for a few hours and here is what happened. It initially surged twice, starting at 2000 RPM down to 1500. Back to 2000 and then 1500 again. From there it slowly worked its way back down to 8 or 900. There it stabilized and started to idle ruff and black smoke. But it wasn't surging like it was. Then I gave it some gas and took it up to about 3000 RPM and let off. It did the same surge twice and work it's way back down around 800 where it stayed ruff. Any ideas with that info?

That sounds like my Toyota Tacoma when it had a blown head gasket. Is any coolant disappearing? I think an exhaust leak could cause the O2 sensor(s) to get incorrect readings, which in turn could cause it to run rich.

Oh and this is a non-turbo. I do have a line that runs from the PCV to the plastic elbow between the MAF and throttle body. I noticed yesterday that when it would surge high smoke would come out of that connection. I removed it and took a look. There was a little oil in there but I wouldn't say it was caked in there by any means, not like it was when I replaced it last year. It was wet oil if anything. I did wrap some tape around that connector and reinstalled it to seal up and leaks there but that didn't make a difference. I don't mind taking off the PCV again and checking it out but will they clog in less than a year or are we thinking there is an air leak there?

Your thread title says GLT, so I assumed it was a turbo. A GLT is a Light Pressure Turbo, which means it has a smaller turbo and lower compression than a T5. The PCV is probably fine if you changed it only a year ago, unless something has come loose.

[rspi]

The only GLT that has a turbo is the '97 850. Man, I would focus on that IAC value, seemed like you were on to something there. If you don't have access to used jy parts let me know, I'll help you out the best I can.

[bensr20det]

Well I went to the local JY and bought a IACV off a '96 with 150xxx miles. Brought it home and cleaned it up real good, stuck it in and same issue. I am at a loss here. Might go ahead and remove the PCV just to see what up. Any other ideas? Looks like the exhaust is crooked but no leaks as far as I can tell.

[j_cd]

Yeah the engine sounds kinda choked, might not be a bad idea to check the PCV again. I'm suggesting you hook it up to VADIS or whatever it's called, not just a hand held scanner.

[bensr20det]

Well got a little good news for once. Decided to have the parts store trade out the MAF they sold me. While it was Bosch and sold as remanufactured it was very dirty on the outside. The guy almost wouldn't take it back because he said they don't sell dirty parts. But I got it swapped for a clean on. Installed it, it ran like garbage for a few minutes and finally came to a point I felt comfortable going on a test drive. The smoke is gone, the intermittent loss of power while driving is gone, the surging at idle is gone. All in all I would say she seems fixed at this point. One thing I noticed now is when I start her it jumps to 2000 RPM and in about 15 seconds falls down to around 8 or 900 and idles smooth with no smoke. Also when I stop at a stop sign the RPM holds at around 1200 for 10 seconds then makes its way down to around 800. I will take it but any ideas why?

[j_cd]

Good deal. At least you got rid of that surging, and she's idling much better. Maybe you've got a sticky throttle cable, or something else in the throttle assembly is causing that.

[rspi]

Pull the plugs and see of any of them look like they are getting to much fuel. Not sure what that would look like but you may have a leaking injector, trying to flood out the car. Could even be the injector relay.