Hit a bump, and now I'm hosed...

[e24mpwr]

Was driving around yesterday and hit a dip in the pavement that was a pretty good shock. Immediately after, the car started bogging when I pushed the accelerator. I popped it in neutral, restarted and popped it back in third for sort of a rolling start. It hesitated a little, then went back to normal. Stopped two other places, and started and ran fine, though I did have a vague smell of gas in the trunk at the first stop (which was only a few hundred yards from the bump). Didn't notice it at the second stop.

Tried to get out this morning, and it started/idled fine, but any load or throttle boggs it to the point of stall.

I've had a previous issue where my AFM door was was balky, and I've pulled the AFM and moved the flapper a little. I noticed a fair bit of carbon buildup on the motor side - not sure if it is from all the bucking/stalling or something else.

I'm going to button up the AFM and try again, but any other thoughts appreciated. The TPS in the car is fairly new, but maybe something got shorted/hurt on the bump?

[carsnplanes]

What exactly did you hit. Just that the suspension bottomed out or did you actuyally strike something underneath the car? I'm thinking an electrical connection or ground might have been jostled loose. As far as engine components like the AFM or TPS, I'm not convinced. ECU grounds or the large plug on the ECU itself? Might just take a jarring to upset a marginal connection.

[Alex E24 E30]

I'm with Jody...I've had friends who have bottomed out the suspension on a hard bump which in turn knocked some sensor loose that wouldn't let the car run right.

Could you have possibly knocked a clot loose in the fuel system and partially plugged a line? Maybe the filter?


Alex

[carsnplanes]

...maybe crushed a metal fuel supply line under the car....
Inspect underneath from tank to engine. Longshot.

[e24mpwr]

I'll check - wasn't close to a bottom-out, but was a good, sudden bonk. Odd that it started and ran perfectly twice after that...

[JRanmann]

On a hunch, postulating the area most likely to shift might check the battery for cracks/loss of electrolyte (which has now likely eaten it's way into your ground cable heaven forbid?)

Just a thought and if it don't crank tomorrow morning, then at least you'll know why?

[86GT635]

I am thinking it is the cold solder joints on the ecu's heat transistor. They are notorious for these sort of symptoms. Reflowing the solder on the post's of the transistor is an easy thing to do if you have ever soldered, and is a thing every 6er owner should do if they haven't already.

[Flash635]

Check to see if the O2 sensor wires aren't crushed, that would produce those symptoms.

[e24mpwr]

I'm going to try to get home in time to look at some things tonight.

I'm hoping something just got jolted loose and not the ECU/etc.

[e24mpwr]

Well - went through the bay today and everything seems to be plugged in. The 02 sensor wires seem fine from the exhaust up to the engine bay. I've got a new fuel filter, and I'm going to try to swap that in tomorrow.

*sigh*

[wildgate1]

I believe I would check the ECU for a loose connection. I had that happen to my 83. Just my .02 worth.

[chicaneS54]

I would be more worried about the fuel smell. Check to make sure that you did not damage the tank or any of the fuel lines.

[e24mpwr]

OK - a little poking around the ECU and things are running again - guess the interior connector had a tiny bit of play and that was the difference.

It is back in the garage - Thanks for Mr. Wingate for the "make sure the ECU is plugged in" and thanks to Greg Rhea for talking me through it. Simple enough, but always good to have a friendly voice to get through it.