M42 puzzle

[ahlem]

Have you had your throttle body off recently? Any stripped studs to the manifold?

[Boris3]

Thanks for the idea but no and no.

[roguetoaster]

It's possible that you have a coolant leak. However, I don't recall my car throwing a code when the it was full on cracked.

Did you rev the car with the TPS disconnected?

The only other item I can dredge up would be the AFM being severely worn or having a lot of condensation under the cap. You don't by chance have that resistor unit in line between the AFM and the harness for it?

[kwill22]

I never got a cel when my head cracked either. After a while started to notice a loss of power on the throttle occasionally and a missed startup maybe 1 out of 5 times I'd start the car. Didn't find out what it was until I had the smoke out of the tail pipe one morning.

And the plug on the harness by the firewall is unplugged too right? Don't remember exactly what it causes but it causes some very noticeable issues.

[Boris3]

Reved it and it flashed a cel. Sorry not sure what you mean by the afm resistor unit.

I did unplug the little connector by the firewall several months ago. Took care of the classic warm start issue.

[Boris3]

Shot in the driveway just now so not the best detail

[Boris3]

[Boris3]

I'm reaching. What are the symptoms of a bad dme and would they fit my situation?

[roguetoaster]

A bad DME generally is limited to the coil drivers. You could easily test to see if you have spark at all four plug wires.

One more thing, I see you have a new intake boot. Does it have both holes plugged in the bottom (one plug, one hose barb)? Did you transfer the internal wire reinforcement thing from the old to the new?

[Boris3]

New boot but I swapped the plug and the barbed connector from the old one, and it came with the internal reinforcement.

Trying to think about what I've done differently lately. Ran tank down to the low fuel light which I had never done before. Filled up at a different station. Noticed the first cel flicker a few days later. I was at 1/2 a tank this weekend when everything got worse. Gas issues, tank rust? Though the gas was clean coming out of the old filter when I changed it.

[roguetoaster]

Try removing that resistor that is currently plugged directly in to the AFM. Not sure if you can see the picture I posted.

[Boris3]

Thanks, on the list for tomorrow. Wondered what that piece was actually. I saw your picture and was just hunting around for more info and found this thread. http://www.r3vlimited.com/board/showthread.php?t=176533

Does the resistor go bad? Anyway, I'll pull it and see what happens. Same thread points to an aftermarket fuel pump issue causing a cel with no code though his issues were hesitation on throttle. I know a PO on my car replaced the fuel pump a while back but haven't looked at what he put in.

By the way I really appreciate all the help!

[Boris3]

Ok tried this again this morning. Disconnected battery to start with clean slate.

Reconnected battery and fired up.No cel for the first minute or so at idle, then starts to stumble

Disconnecting one at a time while running:

-02 sensor: idle smooths out, no cel at idle but if I give it throttle cel begins at 1500 rpm

-TPS: engine dies

-ICV: runs worse and almost dies

-O2 sensor and TPS: dies

-AFM resistor cord: no real difference, maybe runs a bit rougher when removed

So removing the 02 sensor out smooths idle but I still have cel under throttle. Even when slowly increasing throttle the cel starts at around1500 rmp and up. let off the throttle the cel disappears.

Reread codes and had the ICV show up from when I disconnected it. Cleared codes restarted engine with 02 sensor disconnected. Same symptoms with no cel or stumble at idle and cel when I give it throttle. Rechecked codes and none stored.

[kwill22]

You test the ohms on the cool packs?

[Boris3]

Yep, 0.8 ohms for each