Losing power occasionally

[jtripplej]

Can use some help! My 80' spyder has been acting up by while I'm driving it will starts to bog down and lose power. If I up shift it will keep going but greatly under powered. When I would try to down shift I lose almost all power. It doesn't stall but hardly has power. After I make it home and try to start the next day no problem at idle but some times it does sputer and pop then smooths out.I've driven 40-50 miles ok. Next time I drove 5 miles and it started up again. This has been going on for the last two summers needless to say I don't dare go to far.. I changed the plugs, wires, fuel filter and even added dry gas in case there was some water in the tank. The car is driven only in the summer and not too often. I am the original owner. I have changed the air flow meter but many years ago.Any ideas????
Joe

[jimincalif]

check to see if the air flap is sticking.

[majicwrench]

Really need to run some tests as car is losing power, if it was in my shop I would have a fuel pressure gauge hooked in line. One thing very quick and easy to try, run the car with the gas cap loose, just to make sure you are not building up vacuum in tank.
Original owner!! wow!!!! Welcome!!
Keith

[james124]

Have you done a compression test, checked valve clearance? If you don't drive it often, maybe there's carbon build-up on your valves. Maybe try something like Mopar combustion cleaner and fuel injection cleaner. Give us some feedback. Good luck, James

[mdrburchette]

It sounds like what my X19 is doing. I can be driving down the road just fine, but all of a sudden, I press the gas and it acts like I haven't touched it and keeps slowing down. It's a fuel problem with mine because the tach doesn't jump around but stays steady. I pat the gas pedal and it eventually takes off, but not because of me patting the pedal. I've been told to check connectors in the fuel system and check the fuel pump relay. I've already replaced the fuel pump but will install a pressure gauge to see if I'm losing fuel pressure.

[ga.spyder]

Instead of 'patting the pedal', try scratching it behind the ears.They really like that

[jtripplej]

Thanks to all for your input. I checked the air flap and it is fine clean as a whistle. I'll try tommorow to run it with the fuel cap lose and let you know. I spoke to a fiat mech. and will probably bring it in to him. He mentioned that the first thing he will check is the fuel pump pressure. Seems like we are on the same page. hope it will be something simple. Doubt it's compression or valves or it wold be a constant problem not intermintent.

[jtripplej]

OK, I drove for a good 60 miles today and no problem. Ran smooth. Just can't figure this out. Hopefully it will continue to run well. I'm going to put an inline fuel pressure gauge to see how the electric pump is preforming. Didn't get the chance to drive with the fuel cap lose since it ran ok.I checked the vacuum lines and all are good. We'll see what happens the next time out.
Joe

[jtripplej]

Just a long over due post on this problem I had a number of years ago; Turns out the problem, I found by chance, was that the wire from the distributor pick up had worn to bare wire and every so often would short out causing the Tack to fluctuate and the car to lose power. Replaced the pick up and solved the problem. NOW a few years later the same problem has started again. Losing power the other day when I would go over 3K on the tack. But now no fluctuating of the tack. I got home and the first thing I checked was the pick up which was fine. Wire was perfect. So now the fun begins again..If any one has any suggestion I would be glad to hear them Thank you...

[RRoller123]

Check/Replace the 2-way valve in the air return line to the gas tank, it sits right about the rear axle, driver's side. Small white plastic piece, and it is probably clogged. It should pass air under some small pressure, in both directions. The Charcoal canister could also be clogged, especially if it is missing the small black plastic cap on top that snaps in the vent hole, but this is less likely. The 2-way valve could cause the problem and is a common failure.

[bluespider262]

If its carbed check the sock inside the fuel tank.

If its FI I'm not sure if the FI tank has a sock at the end of the fuel inlet or not.

The car will want to stall as soon as you hit 3rd or 4th gear if that sock is causing it to not get the fuel it needs. Mine was almost completely rusted into a solid mass.