Loosing power but not stalling/Has now changed to won't idle

[giuliot60]

Hi.

My 81 has been running great for a while now, but yesterday when I took it out, after about a mile or so, it started sputtering and loosing power. After a few minutes it cleared up and ran fine for the rest of the drive.

I thought it might have been because I had about 1/8 of a tank of gas and on a little bit of an incline before it started to sputter, so I filled the tank.

This morning, I decided to take her to work. She started right up as always and idled fine, again after about a mile she started sputtering and loosing power, but never stalled and I would sometimes get full power back temporarily.

I was able to get her home with some coaxing, gas pedal and clutch/gear combinations and took my VW to work.

I'm thinking it could possibly be a fuel delivery issue, and should change my fuel filter. Some history: I bought the car this spring from an original owner with 81K miles on it. The car was nicely maintained, but was off the road for 4 years with it being started occasionally. After purchasing it, I drained the gas through the fuel filter (which seemed clean and unobstructed), put in fresh gas and some sea foam. I was planning on replacing (and purchased) the fuel filter, but never did since the filter in the car seemed like it was working. I never took the gas tank out either.

I would love some thoughts on this.

Thanks.

[azruss]

there are a few things that could be causing a low fuel situation. the fuel filter is the first place to start.

[giuliot60]

Update.

So out of curiosity I started her up and just let her idle and waited for her to reach operating temp. She idled perfectly fine. After a few minutes I revved her up from the engine and there was a little hesitation and sputtering as I described when I was driving her earlier. I backed off and let her keep idling. I checked vacuum lines with no apparent leaks anywhere. She reached 190 and stayed there with no fan activity. I was surprised that it wasn't going past 190 since she normally operates at 195. Outside temp is about 78 degrees today and dry. I decided to rev her up again, there was some sputtering/hesitation, but then it cleared up and she was revving fine, but temp did not go past 190. Again, I was surprised. She was running great, but still no temp rise or fan. I decided to tap on the sensor on the "tee" at the top of the engine to see if I could possibly activate the fan, but then she stalled and after several attempts, wouldn't start again. So I decided to let her cool off and write this post.

I would think that since she was running fine at idle and eventually revved up with no issues, there isn't a fuel delivery or fuel filter issue. Could it be the cold start injector?

Any thoughts would be appreciated.

Thanks.

[azruss]

I know that connection at the Tee can be a problem. usually it is a go/no go rather than causing just sputtering. check the connection and see if the problem goes away.

[giuliot60]

I'll check. Thanks azruss.

[76was124]

Could it be the cold start injector?

It's not the cold start injector. That only fires the first couple seconds, (when engine is below something like 90F) before the regular injectors take over.

[giuliot60]

Well, good news azruss.

I disconnected the connection at the "tee", sprayed with electrical cleaner, and dielectric greased it, and she started right up. She also seemed to rev up pretty well, so I decided to drive her around for a couple of blocks. She was OK at first, then started to loose power at times. So I brought her back home and popped the hood. By now she was also idling rough, but seemed to be fine when I revved her up in neutral.

This time the fan did come on at 195, and was doing its job.

So, I figured I'd come back here to report the news and see what I should do next. I will probably change the fuel filter since I have one, but another thoughts would be welcomed.

Thanks.

[76was124]

Seems tied to engine reaching operating temperature. Once the problem starts, is there anything that cures it besides letting the engine cool? Does it matter if the engine is under load? No difference with clutch depressed vs. gearbox shifter in neutral is there? Engine oil level, pump working ok?

[hank]

Check this video out - same issue perhaps.

http://www.youtube.com/watch?v=4ypYUq5ri_k

The dielectric may have improved the connection but an underlying wiring issue like the one in the video could exist.

[giuliot60]

Actually 76, my initial problem (which just started yesterday) seemed to exist before it reached temp and clear up after. Now it's happening either way, and especially under load.

[So Cal Mark]

the sensor you're mentioning has nothing to do with the fan, it's the temp sensor the ecu uses for setting fuel mixture from cold start to warm up. That connection is critical, if the connector is loose or broken you need to replace the pigtail.

[giuliot60]

I realize that now Mark. That's why I love this site.

Do you think it could still be the connection? It appears to be on well. I wasn't able to get in there real well though, there looked like there was some greenish oxidation and I mainly cleaned it by spraying it with electrical cleaner, then greasing it. Any thoughts or possibility it's fuel delivery related as well?

Thanks Hanks for the video. I think that may possibly be the culprit. Need to investigate further.

[giuliot60]

Still looking for possible causes.

Planning on fiddling with coolant sensor first, then will replace filter.

[giuliot60]

UPDATE

So I started the Spider today (started right up) and started playing with the wire to the coolant temperature sensor like in the video Hank provided previously (http://www.youtube.com/watch?v=4ypYUq5ri_k), and it reacts the same way. I'm assuming that replacing the CTS pigtail as Mark suggested would resolve my issue.

Anyone know if that part is available from any our vendors, or would I have to get a used one?

Thanks

[azruss]

I bought a complete connection set from Vicks 6 years ago. i have not installed them yet. the wire leads are about 6" long. requires splicing in and using shrink tubing to weatherseal. most wires typically break where the wire enters the plug. from watching the video, it looks to be that way. A little wiring tip. cut your wires to different lengths so your splices are not next to each other.