2.25 petrol not running well under load

[kellen302]

My "misfire so occasional I wasn't sure it was there" has turned into a "sounds like a rev limiter" sputtering under high load lower rpm conditions such as taking off from a stop, accelerating from below 1500-2000rpm in 2/3/4. Or any acceleration near top speed on the highway in 4th+OD. Off of the highway it seems to clear up as it breaks through 2000rpm. Starts and idles fine.
I've cleared the sediment bowl on the pump, there was a little bit in there, but not much , and nothing big.
Cleaned out the bowl on the Solex carb, again, a little bit of fine sediment, but nothing significant
Cleared oiut some trash off of the jet at the top of the venturi, but I'm not sure if that fell off of my glove when I pulled the top off.
Sprayed out the main jet/holder
sprayed out the accelerator pump banjo/screen
sprayed out the jet/holder on the back of the carb body.



Fuel system was entirely replaced 2 years ago with a stainless tank from Ike, an original fuel pump I rebuilt, and all new lines. The second tank has not been replaced yet, but I have not used it in a while.


Ignition is a freshly rebuilt points unit from the Distributor Doctor that I installed in the spring during the full rewiring, truck has run flawlessly for a couple thousand miles since then.

I'm trying to track down another fuel pump to see if that will narrow things down, but I'm open to any and all ideas. Going to tear into the fuel system and carb some more tomorrow. I need to have this back on the road for a trip on Friday.


Thanks!

[biffidum]

I would check the advance mechanism (timing gun needed). I would also check and adjust the valves given what you have already done.

[siiirhd88]

I had the same thing on the TR-3 when the ignition coil failed. It would start and run OK except under load or hard acceleration when it would break up.

Bob

[Rusty Goose]

Air filter?

[72Rover]

Although new-ish, crappy points can masquerade as all sorts of supposedly fuel-related issues. Check.clean and gap the points. Throwing in a new condenser might be a good idea, though condensers are typically an all-or-none issue. (I have had a brand new, bad one right out of the box.)

But fuel itself could be the issue. With up to 20% ethanol added, petrol just doesn't 'last' these days. Ethyl alcohol is hydroscopic and will pull moisture out of the atmosphere: it will "go off" PDQ. Ethanol is one of the greatest travesties foisted on this country, as it 'costs' more in energy to manufacture than it produces. Despite the claims of being good for the environment, the only 'benefit' is obscene profits for a handful of companies, like Archer Daniels Midland Corp. But I digress....

If the vehicle hasn't been driven a lot lately, I would suspect the fuel, since delivery of same has already been addressed.

[Paul D]

I had the same thing on the TR-3 when the ignition coil failed. It would start and run OK except under load or hard acceleration when it would break up.

Bob

I had the same experience with my '66 IIA this spring. It started running poorly, as Bob describes, then eventually failed completely. This was after I opened up and cleaned the carburetor, drained and replaced the fuel in the tank, etc.

[kellen302]

I think I have a spare coil floating around to try. I'll check the points as well. Fuel is fresh as I have been daily driving it since I finished rewiring in June.

[72Rover]

A sign of a bad or going-bad coil is one that is overheating. All coils get warm in use, but they're not supposed to get bloody boiling. (Some coils have built-on heat sinks.) Had an old Chevy wagon, and the coil would get close to blistering. Sometimes, I would use a wet rag or pour water on it to cool it down, and it would start right up. Another time, without access water - or beer - I mashed a half an orange on it...and it worked a treat. On the Rover, the standard coil placement is one of the worst places WRT heat.

[64osby]

When was the last time a compression test was performed?

Low numbers could be valves, mentioned above, or a worn engine.

Years ago my lump was replaced with a Turner, after testing showed 60 PSI on two cylinders. It would run great at low speeds, acceleration was slow and going up hills was terrible. An engine with good compression had no more issues.

[kellen302]

The engine has an alleged 17k miles on it, as it was replaced about 4k before I acquired the truck. The part that has me stumped is that it clears up at higher rpm. I'll check all of the ignition stuff this evening.

[kellen302]

Turned out to be a bad coil/points gap. I adjusted/cleaned/greased the points at the same time as replacing the coil (which in hindsight spent a lot of time above a major exhaust leak). Runs better than it has in a while and I had to readjust the idle to bring it back down.

I'm going to blame the Jeep in the parking lot at work for spreading it's ignition related misfire like a disease.

Thanks for the suggestions!

[Paul D]

Got to love those cheap, simple fixes.