Loose power at 3000 rpm's

[Thor]

It's been a while since I had to troubleshoot the mg and want to get ideas on where I should start looking for the following problem. At around 3000 rpm's I loose power as if the motor is maxed out.

The midget is a 1978 1500 and has been working well all Summer long without until recently I was cruising at 60 mph and the motor died. I was able to get it started with several episodes of cranking the starter but since then I've a real lack of power at 3000 rpm's.

My first thought was that the distributor slipped or something. I checked that this morning and its nice and secure. I also checked the timing and its about 13 ATD which from what I recall is where I set it at during tuning since it ran best at that setting.

So does anyone have thoughts what else I should be checking to see if that is causing the problem. Thanks for suggestions.

 

[leecreek]

plugged fuel filter? I'd check all the fuel delivery sysyem if ignition checks ok.

 

[PeterC]

Thor, are you able to rev the engine above 3K when not driving under load? If so, check the high tension stuff, coil, cap, rotor, wires. Those items will give that symptom as well as the fuel filter be clogged.
Peter

 

[Bugeye58]

If you're still running points, the gap may have closed up due to wear on the rubbing block.
Jeff

 

[Atrus]

I agree with fuel filter. Had this issue this past summer. At the advice of forum members, I cleaned the fuel filter (even though it looked clean) and the problem went away.

 

[justaguy]

I would check fuel delivery 1st & then electrical. Any funny noises happening when it looses power? (sputtering, ect...)

John

 

[Morris]

Always a good idea to check the rubber dashpot diaphram if you are running the stock carb. A hole in the diaphram will cause you to loose power. But it prolly wouldn't cause your car to die. So it's likely an ignition/fuel delivery problem.

 

[Thor]

Sorry that it's taken so long to get back to everyone. We had another 3" of rain this week so its been hard to get the car out and try some of these suggestions. Finally a break in the weather though.

Between downpours I managed to reved the engine above 3500 rpms while under no load and noticed no sudden power loss but could hear a few dropped firings, what I'll call "misfires". Underload that seems to be much more noticable.

I'll try and bypass the fuel filter briefly to see if I get an improvement. I hope its as simple as that. I would be surprised though as I just replaced the fuel filter two months ago with one of those King Fuel filer/regualtors. Looks clean but as one suggestions sometimes appearances can be deceiving.

I'll get back to everyone as soon as I tried out more of these suggestions. Thanks again for all of them.

 

[justaguy]

[ QUOTE ]
Sorry that it's taken so long to get back to everyone. We had another 3" of rain this week so its been hard to get the car out and try some of these suggestions. Finally a break in the weather though.
Between downpours I managed to reved the engine above 3500 rpms while under no load and noticed no sudden power loss but could hear a few dropped firings, what I'll call "misfires". Underload that seems to be much more noticable.

I'll try and bypass the fuel filter briefly to see if I get an improvement. I hope its as simple as that. I would be surprised though as I just replaced the fuel filter two months ago with one of those King Fuel filer/regualtors. Looks clean but as one suggestions sometimes appearances can be deceiving.

I'll get back to everyone as soon as I tried out more of these suggestions. Thanks again for all of them.

[/ QUOTE ]

Silly question but have you checked to make sure you spark plug wires are all in the right place on the engine and dist cap? I had a boat one time that I bought real cheap because the owner could not get above 2300 RPM under load. It would rev fine with a water hose hooked up to it but once on the water NUTTIN!.... He must have thought he really got one over on me... Turned out that his mechanic had reversed two of the spark plug wires. The two cylinders just happened to be close enough together in the firing order that with no load it was hardly noticeable. I switched the wires back to where they belonged and got out the skis... /ubbthreads/images/graemlins/thumbsup.gif

 

[JeffS]

How about the condenser? If its not brand new, throw in a different one! That'll cause your exact situation!
Jeff

 

[caseyjones955]

I would lean definatly towards fuel managment if idle and low speed operation are smooth. I have seen fuel starvation manafested as high speed missfires (and eventually sputter/die) and just a plain lack of high speed power w/o much missfire. If fuel filter is clear and all the other mentioned systems check out you might throw a fuel PSI gauge on it and make sure fuel pump is operating at the correct pressure.

Being also an air cooled VW nutcase I have spent some time dealing with crappy mechanical fuel pumps. Lots of headaches with lower end fuel pressure regulators also, if you have one of those I would definatly try bypassing it for a short drive.


sounds like you are on the west coast!

Good luck
Tony

 

[Thor]

Update: I bypassed the fuel filter and the engine rev past 3000 without the misfire, etc I had noticed before.

Unfotunately I was unable to take the car out on the road to see if that completely resolved the loss of power or not as I had just recently switched car insurance from regular to classic and there was a 14 day lapse between the two. I had not turned in the plates during that 14 day lapse so the State required either me paying a civil $112 dollars fine or turning in the plates for 14 days. Being cold and wet outside I opted for the 14 day turn in. I figure I can buy a whole lot of filters for the money I save.

Anyways the problem does seem to be fuel related. It will be interesting to see if just by replacing the fuel filter the problem is completely resolved or I am thinking it might have to do with the "Filter King's Regulator portion" as well. I was reading its literature and it states that if under acceleration the carbs are starved or the engine stalls the pressue will need to be adjusted. It came preadjusted for the midget and I have had no problems until recently but I suppose that something could have happened to it.

Thanks everyone for your suggestions and help

 

[jlaird]

Naaa, you got it. All is well.