My T is always jerking and it sputters at high speed

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Model T Ford Forum: Forum 2014: My T is always jerking and it sputters at high speed
Top of pagePrevious messageNext messageBottom of page Link to this message  By Willi Kuehnis on Tuesday, June 17, 2014 - 02:58 am:

Since 3 years, I have a Ford-T 1925 roadster pickup. I drove now 4500km (2600miles)
Itís not a show car, itís a runner.
It has:
- new carburator
- Z-Head
- distributor
- battery-ignition
- flame thrower ignition coil
- new crankshaft (because the original broke last year)

Now Itís always jerking and it sputters at high speed, especially when itís hot.

My maximum speed is about 80km/h (47 miles/hour)
But at 50 to 60km/h at starts jerking and sometimes also the engine donít work for about 2 seconds, but it never comes to a stop. If the engine is hotter, then the problems starts at lower speed.
It starts very good with the starter, with cold engine it starts with the choke in less then 1 second, with hot engine it starts at the shortest press of the starter button.

I already:
- changed the 4 spark plugs
- changed Ignition coil (flame thrower)
- changed - distributor head + finger
- changed condenser
- changed all 5 ignition cables
- remount the Z-head with a new gasket
- dismounted and cleaned the gas tank
- mounted a gas pump with a bypass, which has a valve to close it (in case, the gas pump stops working)
- mounted a heat reflector between gas line and exhaust pipe
- mounted the gas line as far as possible from the exhaust
- installed a insulation tube around the gas line, where it crosses the exhaust pipe
- have a glass gas filter close to the carburator , where I can see, that itís always full
- controlled the spark gap
- controlled the point gap
- checked the ignition timing several times (lever at top - piston at the top)
- tried with a lot of different settings of the carburator (especially changed the setting of the high speed needle), but itís back now to the initial settings
- removed the carburator filter
-....

----> finally after all this changes itís still the same.

At the moment, I donít know what else I could do .

Any suggestions ?

Thanks
Willi


Top of pagePrevious messageNext messageBottom of page Link to this message  By Frank van Ekeren (Australia) on Tuesday, June 17, 2014 - 03:13 am:

Worn valve guides would be another thing to check!


Top of pagePrevious messageNext messageBottom of page Link to this message  By Kevin Whelihan on Tuesday, June 17, 2014 - 06:22 am:

You might have some crud stuck in the gas line that is causing the engine to run lean. Had the same problem with mine. Cleaned out the blockage and everything runs fine again.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Willi Kuehnis on Tuesday, June 17, 2014 - 06:57 am:

Valve guides:
Saturday I removed the head and checked also the valves (b ut nut the guides) everything looked OK.

Gas line:
like I said: I removed and cleaned the gas tank, replaced the gas line and the filter just before the carb is always full.

Willi


Top of pagePrevious messageNext messageBottom of page Link to this message  By Willi Kuehnis on Tuesday, June 17, 2014 - 07:05 am:

Gas:
The gas tank has also a sediment bowle, which I cleaned.


Top of pagePrevious messageNext messageBottom of page Link to this message  By G.R.Cheshire on Tuesday, June 17, 2014 - 07:09 am:

What of carb. are you running?


Top of pagePrevious messageNext messageBottom of page Link to this message  By Seth from NC on Tuesday, June 17, 2014 - 07:13 am:

What G.R. is asking. What carb are you running and have you tried adjusting it while you are driving?


Top of pagePrevious messageNext messageBottom of page Link to this message  By Ricks - Surf City on Tuesday, June 17, 2014 - 10:24 am:

Run a grounding wire from the disturbutor head to the engine block.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Ken Todd on Tuesday, June 17, 2014 - 11:04 am:

Try removing the "filter just before the carb".


Top of pagePrevious messageNext messageBottom of page Link to this message  By Norman T. Kling on Tuesday, June 17, 2014 - 11:11 am:

How are the bushings in the distributor shaft? If they are loose, it will change the dwell of the points making it run unevenly.

Most likely, though, a fuel starvation problem.

One solution would be to slow down! :-)
Norm


Top of pagePrevious messageNext messageBottom of page Link to this message  By Charlie B actually in Toms River N.J. on Tuesday, June 17, 2014 - 11:45 am:

Rick's ground wire is a good suggestion. I was thinking about a worn distributor shaft/bushing which will cause the points to bounce or not operate well at higher speeds. Classic high speed miss problem. It's usually OK at starting/low speed conditions and acts up at higher RPM's. The only thing going against this is that engine temperature would not affect it. That is if that's the problem it would be there on a hot or cold engine.


Top of pagePrevious messageNext messageBottom of page Link to this message  By John Semprez-Templeton, CA on Tuesday, June 17, 2014 - 12:11 pm:

This sound like a fuel starvation problem to me. Ignition problems usually cause backfiring. Fuel problems could be caused by a blockage, vapor lock or plugged vent. You might also check the float valve for bad behaviour!


Top of pagePrevious messageNext messageBottom of page Link to this message  By Seth from NC on Tuesday, June 17, 2014 - 12:32 pm:

He hasn't told us yet what carb he is running - that info will help a lot in the diagnosis.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Dan Hatch on Tuesday, June 17, 2014 - 01:36 pm:

Gas Filter, not enough flow


Top of pagePrevious messageNext messageBottom of page Link to this message  By john kuehn on Tuesday, June 17, 2014 - 01:55 pm:

Sounds like vapor lock to me. Check you gas cap.

If you have an extra cap drill the vent hole a little larger and see what happens.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Anthonie Boer on Tuesday, June 17, 2014 - 02:12 pm:

Willi : where are you living ? I can't see it on your frofile,perhaps some one near you can help you. First of all TROW away that glass gas filter. 80 km an hour, do you like to have a two pice crankshaft .
Toon


Top of pagePrevious messageNext messageBottom of page Link to this message  By Tim Williams on Tuesday, June 17, 2014 - 04:02 pm:

What about just bad gas? Bad batch from the gas station?


Top of pagePrevious messageNext messageBottom of page Link to this message  By Anthonie Boer on Tuesday, June 17, 2014 - 04:19 pm:

Willi, this is what i mean.
1661R
Toon


Top of pagePrevious messageNext messageBottom of page Link to this message  By Steve Elliott on Wednesday, June 18, 2014 - 10:20 am:

Rick has it, Run a ground wire to the Dist. It fixed mine. Also your coil are you running 6 volt. Use a 6 volt coil. If not 12 volt to 12 volt. Keep checking point gap. On occasion


Top of pagePrevious messageNext messageBottom of page Link to this message  By Jerry VanOoteghem on Wednesday, June 18, 2014 - 01:32 pm:

Willi,

I also agree with Ralph. Try a ground wire in the distributor head.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Willi Kuehnis on Friday, June 20, 2014 - 04:18 am:

I use the modern style carburetor, which is sold by TexastParts, Snyders...


Top of pagePrevious messageNext messageBottom of page Link to this message  By Willi Kuehnis on Friday, June 20, 2014 - 04:28 am:

About "Ground wire": This sounds interesting: But I don't understand: From where on the distributer head ?


Electricity: is on 12Volt

Carburetor: (modern Style): I tested around a lot of different positions between 1 and 2.5 turns of the high speed, now it's back on 1.5 turns

Antonio Boer: I could show you almost the same picture: last year I broke my crankshaft, but not at high speed, I was dring slow in a city. Now a mounted the much better crankShaft.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Willi Kuehnis on Friday, June 20, 2014 - 04:38 am:

@John Kuehn: About vapor lock: I also was thinking about it so I drilled now a small hole into the gas tank cap.

@Frank: Worn valve guides: last winter when I replaced the broken camshaft, then I also installed new valves and reamed teh guides and also new tappets.

@Ken Todd: Good idea: I will try removing the "filter just before the carb".


Top of pagePrevious messageNext messageBottom of page Link to this message  By G.R.Cheshire on Friday, June 20, 2014 - 08:48 am:

Willi: if that carb looks like this
then Mine did the same thing until I added a fuel pump which is why I got rid of the P.O.S. (MHO) and went back to a kingston that lawnmower carb is worthless.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Charlie B actually in Toms River N.J. on Friday, June 20, 2014 - 10:35 am:

The ground wire must run from the piece that turns to a piece that doesn't. That is: the distributor head turns to adjust the timing. That's potentially a poor ground. The lower section doesn't. Is bolted directly and solidly to the engine which is usually solidly grounded through numerous points of contact with the frame which is where the battery ground strap is connected. If it's really sloppy vibrations could cause the dist to lose and regain it's ground but like I said earlier: this condition or worn dist shaft bushings causing the points to bounce would not be affected by engine temperature. It would happen all the time hot or cold.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Willi Kuehnis on Friday, June 20, 2014 - 11:30 am:

@G.R.Cheshire: of course, my carb looks like this. This is the modern style carb they all (Texas,Snyers.Macs) sell and say it's good. I can't test everything myself, so I have to trust the specialists ;) So why do they offer it ?

Willi


Top of pagePrevious messageNext messageBottom of page Link to this message  By G.R.Cheshire on Friday, June 20, 2014 - 11:42 am:

IT works with a fuel pump but, the bowl is way too small. this one was on my 27 which has the fuel tank much higher than the earlier "T's" and I still could not get enough head pressure to make the carb work correctly at higher speeds the other problem I had was I could not adjust the high speed jet to where it wouldn't run rich when I was running a fuel pump went to the vendors and none of them could sell me a rebuild kit for that carb.
as Royce told me the best place for a lawn mower carb is (not surprisingly)on a lawn mower! I think the reason these sell at all is it is easier than finding the correct carb and refurbishing it


Top of pagePrevious messageNext messageBottom of page Link to this message  By Seth from NC on Friday, June 20, 2014 - 11:58 am:

Yeah Willi get you a Stromberg OF rebuilt by Stan Howe and it'll out-perform that law mower carb. Also it's a period correct carb for Model Ts. www.strombergof.com


Top of pagePrevious messageNext messageBottom of page Link to this message  By Willi Kuehnis on Monday, June 23, 2014 - 10:47 am:

I ordered now a Stromberg OF from Stan Howe - hope it helps ;)


Top of pagePrevious messageNext messageBottom of page Link to this message  By Seth from NC on Monday, June 23, 2014 - 10:52 am:

Yup! That plus getting rid of the fuel filter should produce some pretty mind-blowing results. You will be pleased.


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