Gremlins? Voodoo? Gypsy curse?

[jj big shoe]

The first problem was due to a vacuum snafu which I think made it run so lean it ruined the plugs due to the excess heat. Once I fixed the vacuum problem, I figured out the plugs weren't firing I used the ones from my old engine and it fired right up. I had a bit of trouble getting the timing and idle adjustments correct, but once they were she ran like a striped ape (aside from the ticking which I haven't quite determined whether its an exhaust leak or the new cams and lifters). Anyway, I knew I still had to dial in the fast idle since it idled pretty high when it was cold. No big deal, I thought. I'll mess with that another time.

 

I drove it on a few neighborhood errands with no problems and once up to Tampa and back, about 100 miles. Seemed fine. I went to start it about a week later and it bogged and sputtered and wouldn't stay running kind of like if you yanked off a couple plug wires. I didn't have time, so I took my other car. I thought it might have something to do with the weather since it was colder (about 45*F which is cold for Sarasota) and rainy. As I was t'shooting it she started running right again. I figured that it might be due to the weather drying out and heating up and that it seemed to run right once the engine got up to temp and blew out the carbon and unburned fuel it built up when running poorly earlier.

 

So this afternoon I adjusted the fast idle to spec and it seemed to be running right even though it was rainy (not cold though) and drove it up to Tampa again. I stopped for about 20 minutes and it fired right up when I was ready to leave. About half way back home while cruising steadily on the interstate at about 70mph, it started to sputter and bog again. I had to keep it above 3000rpm or else it would die. It got so bad I had to pull over on the shoulder. I checked for loose plug wires (about all I could do with no tools or flashlight in the rain) and they were fine. I decided to limp it to the next exit where there was a gas station with cover and some light. It was bucking like crazy. I prolly looked like a drunk twelve year old who just stole his first car and didn't know how to drive stick. I had to keep the revs at 3000 to 4000 to stay running and when I stopped it would die. I finally got to a station and popped the hood. I pulled off the air cleaner cover and lifted the cleaner a bit to have a look at the throttle linkage. Seemed fine, so I started it up again and it ran fine. I put the air cleaner back together and drove it home without any problems at all. WTF?

Do you think the problem is an electrical connection or would a sensor bug out like that? If so, what sensor would cause the heaving and lurching I described?

 

Thanks for the long read. My eyes and fingers hurt now.

[GhostPath]

Could be TPS, Mass Air Flow meter, or the wiring to either. Sounds like whatever it was, you bumped or moved it when you took the air cleaner off.

 

 

Might also be fuel pump or trash in the tank.

Edited January 19, 2008 by GhostPath

[GrimGreg]

Your trip home sounds like my 3hr trip home(normally 1.5hr) when I realized my fuel filter was clogged.

[95shakinPF]

I'm with ghost on this one! After the read, My first thought was cracked air intake tube(or the like). Sounds as though its sucking air between the MAF and the throttle body, and was closed off after messing with air cleaner. Maybe try spraying some throttle body cleaner around while shes running. If she starts sputtering then, you've found a vacuum/air leak!!

Just a thought Trust me, I know that intermittent problems can sometimes be a pain so GOOD LUCK!! Hope you find it!!!

[Slick]

*has flashback to king*. checked yer injector wires/injectors?

[Mookie]

When my 02 sensor was bad, highway driving would do the same. I could drive for a bit, and then it would start bucking, surging, etc. Basically missing.

Once I slowed down as I coming off the highway or to a stop, it would die. Turning the key off and then back on again to start the engine would usually fix it for a few more miles. If not, I'd have to sit for a few minutes.

 

Mine didn't throw any codes for it, but have you checked just in case?

[jj big shoe]

And the winner is...

 

 

GhostPath!

 

After I posted, I got to thinking about the sequence of events that got it running again at the gas station. I thought maybe I moved the wiring harness enough to allow whatever was loose to make good contact again and that's why it fired back up and I was able to make it home.

I ran the codes and got a "12" which pointed to the MAF sensor so I popped the sensor off and it looked ok, but I swapped it with another on a spare TBI I had and it fired up. Then I wiggled the wires around and it sputtered and died. I pulled back the insulation on the harness and the wires all looked good but the connectors themselves seemed like they could be a bit tighter. I bent them in so they would make better contact with the "blade" connections on the MAF, cleaned them up a bit and now it seems ok.

 

Thanks for the input, guys. I appreciate it.