power loss, surging on acceleration, mpg loss

[SLB]

I'm stumped. My 90 Festiva (5 speed, L Plus, 411,000 miles) has started surging while accerating from a stop, has a loss of power at hiway speeds, and has gone from the lower 40s to mid to lower 30 in fuel mileage. It runs without missing at any speed. I have replaced from a parts car - cat converter, MAF box, throttle body and attactments. New fuel filter, oxygen sensor. It's about time for the next 60k mile tune up - timing belt, plugs & wires, etc. It takes a while to get to 65 or 70 on the interstate. A head wind of the slightest grade and it slows down. Any on with any ideas?

[ejp2fast]

I'd check compression next. I had a surging and power loss when my no. 3 cylinder had not much compression (ended up being exhaust valve had huge burnt spot in it).. how is idle? try pulling the plug wires one at a time and see if the engine dips.. try that.

[hawkdoc60]

Compression is a possibility, but the symptoms sound like a vacuum leak to me. I would check the condition and security of all your vacuum lines. If there is none damaged, you might want to check your intake manifold gasket.

[jglutz]

My experience...if you would replace 'surging' with 'lunging'...probalbly not a compression problem.

Compression problems show up as a performance dog and lots of tail pipe smoke afeter warmed up. Also compresion will show up when going up a hill or any increased load. Just a dog.

Your problem sounds more ignition or ground related. Ignition could include timing components. My first step would be to check the internal conditions of the cap and rotor followed by wires and plugs followed by the ignition coil followed by the timing belt.

The problem may be in the pick up module internal to the Dist. I have seen previous post describing alot of crud in that area resulting in similar symptons.

[SLB]

Thanks for the ideas. I will check out the vacuum lines. I have checked compression - all about the same. I can't remember for sure what it was - I think about 115. I do remember about the time this started smelling something getting hot after driving. I never found what it was. I could smell it from outside the car but couldn't find anything under the hood or underneath causing the smell. It has since stopped the "hot" smell but now it's doing this. Related? I don't know. Wouldn't an ignition issue cause a miss? If not at idle, certainly during acceleration. There is no smoke from the exhaust.

[cubstiva1]

Thanks for the ideas. I will check out the vacuum lines. I have checked compression - all about the same. I can't remember for sure what it was - I think about 115. I do remember about the time this started smelling something getting hot after driving. I never found what it was. I could smell it from outside the car but couldn't find anything under the hood or underneath causing the smell. It has since stopped the "hot" smell but now it's doing this. Related? I don't know. Wouldn't an ignition issue cause a miss? If not at idle, certainly during acceleration. There is no smoke from the exhaust.

this is exactly what mine is doing, down to the smell. if you figure it out b4 me let me know. its really bothering me getting bad mpg. and running so weak.

[cubstiva1]

today i changed my plugs (didn't seem to change much) and then i retarded my distributor some and that has helped a bunch. idk if this will help you, or if it will help my "hot" smell. but i feel i've gained back some power. can't wait to see if i can see any mpg gains.

[hawkdoc60]

The "hot" smell sounds like a possible lean running condition. The leaner the fuel/air mixture, the hotter the engine runs.

[cubstiva1]

The "hot" smell sounds like a possible lean running condition. The leaner the fuel/air mixture, the hotter the engine runs.

but my gauge on the dash never heats up even after a long trip.

[boosted_eclpse]

but my gauge on the dash never heats up even after a long trip.

My brothers truckstiva is the same way. We let it idle for atleast 45mins to a hour and the needle barley moved. What is normal running temp on these cars?

[cubstiva1]

but my gauge on the dash never heats up even after a long trip.

sorry let me restate that, it heats up, but never gets "to hot" or over heats

[miami man]

i have had two festivas and the temp range were both different.

[miami man]

maybe it is a lean surge problem on it.

[liflod]

Did you evr find the solution?

[i218127]

Sugring generally means not getting enough fuel. Not enough, then enough or too much. Could be unsteady pressure. Stcking Pressure regulator? The presure regulator is controled by engine vacum. (Burned rubber line and rubber smell) Restricted return line? That vacum leak is also a good bet. I think physical mechanical problems is unlikely.