Mongo

Bill,

I don't know if all is well yet. I'm getting ready to leave for work now and thought I'd check my thread out before I go driving. The commute will be a good test to see if it does it again. The MAF was definitely not unseated on the car when I started it without the airbox, which is even more confusing.

Mongo

No change in how it runs. It is still idling really low when coming to a quick stop and in traffic. This time before I shut it off in the parking structure it was idling at 300-400 RPM!

Help...

ew928

Was told that during idle, throttle is closed and only air comes in via the buzzing ISV.
Think you said you verified that the throttle is really fully closing when off throttle.
Just wondering if the throttle isn't hanging normally and when you get off throttle quick and it has time to settle that then the throttle is really closed. Also applies to triggering of idle switch.

Mongo

I checked for that yesterday too while the engine was running. No hanging..

Glenn M

Is it possible that the MAF boot has a tear?

Glenn

Mongo

I thought about that possibility yesterday and was going to tear into it again this weekend just to see if I can see anything with a flashlight. This morning the car wasn't doing it badly. I did notice though that the car's shifts are still firm. I'm going to try and adjust the vacuum modulator on it to soften the shifts. When I slowly come to a stop, the idle is fine at almost 700 RPM. Because of that, I have ruled out a cracked intake / MAF boot.

Mongo

Small update. Car stalled out yesterday when doing a warm start and pulling out of the parking lot. Seems like it's only affected when it's hot and when I feather the gas pedal. However, when I came home yesterday it almost did it again in the driveway. I popped the hood and checked the linkage out. Seems like it doesn't close completely when I barely open the throttle. I greased the heck out of the linkage with WD40.

This morning after the WD40 soaked overnight, it wasn't stalling when it warmed up nor did it have a low idle. However, I didn't shut the car off and try to a hot start. The Temp II sensor wire connector still looks beat up pretty bad. I have a 2-pole connector from Roger to solder in to replace the old harness with the torn off sheathing. I hope that a Temp II connection issue is the case. It doesn't look like I have any leaks in vacuum lines. Still need to pull the MAF and inspect the MAF boot.

Anyone know if I can replace the MAF boot without yanking the intake.........again?

Mongo

Looks like a vacuum leak somewhere. I have verified the MAF is sitting right. Removing the airbox causes it to stall because of more air entering the engine. There is false air coming in somewhere under the MAF...maybe ripped boot or breather pipes. Will look into it more in the morning.

On a side note. My Temp II sensor wiring just crumbled on me!

Mrmerlin

check the plastic connectors that plug into the sides of the MAF boot they are known to crumble, also there is a chance that the ISV hose has a split in it some of the new hoses seem to split along the mold lines to see this you need to remove the intake

Mongo

Funny how you mentioned the split. I am on my second ISV hose since the first one did that. I hope that is not the case again. I'll check out those plastic elbows though. I replaced those too but the passenger side is always thinner.

Mrmerlin

For Andy from another board........

I was looking at Rennlist tonight, using my other screen name, and I see that Andy Serrato, otherwise known as "Mongo" cannot keep his car from running rich.

His problem is the same I have had since I bought my car 10 years ago. The connector at the MAF corrodes, and if you clean it with Deoxit, it goes away for a while.

In his case, I would definitely clean that connection. Then I would use the manuals to troubleshoot the problem- what sort of resistance in Ohms is he getting between terminals 3 and 6 of the MAF? Has he tried checking the resistance between the MAF connector and the terminal at the LH computer? It should be very little.

-These cars are now upwards of 25 years old. They have LOTS and LOTS of small and delicate electrical connections, and the computers used use very little voltage, which simply means that a tiny film of crud can cause huge loss of power and efficiency.

I don't post at Rennlist anymore; I would appreciate someone posting a link to this to him, or at least cut & paste.

N!

Mongo

That was the first thing I did when I started noticing problems. The electrical connectors in the harness don't have any crud on them.

The temp II sensor harness is repaired and the car is still idling like ****. Here is a video below. The negative cable was disconnected on the battery all night long so the LH brain has been long cleared of any idle map. Car is starting to **** me off.


In the video, I am trying to keep the car from stalling by feathering the throttle just a little bit. You can hear it bog down and the ISV catches it. When I started it when it was cold, it ran good! When it warmed up, you can tell it's running like crap.

Mrmerlin

what is the fuel pressure doing??
It should be about 55psi.
Try removing one injector wire at a time see if any of them dont make a difference

Mongo

I don't have anything to measure it. I'd like to get one of those gauges though that attach to the fuel rail.

Mongo

Just came back from a drive. It feels like it's down on power. When I blip it, there is hesitation. If I lightly press the gas it wants to stall out.

When I did a WOT run it felt slow. I think I hear a pinging on occasion through the exhaust. You can hear it on the video too I believe.