'91 Ranger
2.3l 5sp manual trans.
107049 miles
last 8 of vin: NTA32937

Engine starts and runs normally in neutral. Throttle/engine response normal in neutral. When starting out in 1st gear, engine begins to hesitate, and is not responsive to throttle. I have to feather the throttle for the engine to recover. Replaced plugs, wires, checked air filter(ok). I'm not sure when the fuel filter was last changed. Timing belt reported to be changed a few months ago. The situation "just started". Symptoms do not occur with the rear wheels off the ground.

I'm a diesel refrigeration technician by trade, and these gas-ers throw me once in a while.

Thanks,

Chas

Your problem is only showing up under load. You need to first use a spark tester to determine if the spark is dropping out when this happens. If so, the coil is likely. Also take a vacuum reading. If the vacuum is low, suspect a plugged Catalytic Converter




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Being a diesel mechanic, I pulled the spark plug wires one at a time to listen for an engine "miss". Being it has 8 plugs, some made a differance, while others didn't.

I'll check the vac, how do you tell if the catalytic is out?

Chas

It will only do any good to check the spark as the failure occurs. It won' tell you anything if test at any other time.




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After doing the tests, and further inspection, I didn't find any vacuum leaks, but plenty of exhaust leaks. The muffler looks like it was hit by a shot gun, and most of the gaskets from the manifold through to the catalytic converter are leaking. The filler tube on the gas tank also has a hole in it. I found this out when I put some more gas in the tank. I didn't notice any vac at the carbon canister, but had plenty everywhere else.

I did notice a major hesitation at the throttle just past opening the body. It almost kills the engine.

Chas