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Discussion Starter · #1 ·
Hello Dakota people,

My 1990 automatic Dakota jolts forward when it shifts gears. I feel like it might be shifting a little late or something. It also feels like its missing some power, like its clogged somewhere but I’m not sure.
 

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Has the jolt just started?

Also, due to the 'it's clogged somewhere' feeling, I'd be checking all of:

Plugs.
Cap.
Rotor.
Spark plug wires.
Air filter.
Fuel filter.
Exhaust (especially catalytic converter!) for pluggage.

It could be that due to age, the cat is partially plugged; when the RPMs drop, it gets a burst of fresh air through the exhaust causing the jolt.

Or the jolt could be completely unrelated; but I'd be checking that possible pluggage first.

Especially since if it plugs enough, it'll back feed through the EGR valve and melt the modulator (the plastic valve down by the throttle linkage that feeds the metal EGR valve).

RwP
 

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Discussion Starter · #3 ·
Has the jolt just started?

Also, due to the 'it's clogged somewhere' feeling, I'd be checking all of:

Plugs.
Cap.
Rotor.
Spark plug wires.
Air filter.
Fuel filter.
Exhaust (especially catalytic converter!) for pluggage.

It could be that due to age, the cat is partially plugged; when the RPMs drop, it gets a burst of fresh air through the exhaust causing the jolt.

Or the jolt could be completely unrelated; but I'd be checking that possible pluggage first.

Especially since if it plugs enough, it'll back feed through the EGR valve and melt the modulator (the plastic valve down by the throttle linkage that feeds the metal EGR valve).

RwP
Hello again Ralph!

I recently put in a brand new catalytic converter w/ oxygen sensor.

I Didn’t change the spark plugs, air filter, fuel filter, spark plug wires or fuel filter when I bought this thing a few months ago.

Not sure what you mean by cap and rotor.

Could it be that my California grade cat is too restrictive?....

thanks!
 

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If you follow the plug wires, they go to a distributor in the back. That has a cap and a rotor inside. This distributes the spark to each cylinder (hence the name).

Before you worry about anything else, do the filters, the cap, the rotor, the plug wires, and the plugs in order to verify it's not just having problems firing properly.

One other choice, if you just changed the cat, and it was coming apart, may be pluggage in the muffler; since I'm fond of glass packs, my take would be to cut the old muffler out and replace it with a glass pack :p but you may want to check back pressure first to make sure it's not plugged.

The California cat, if it's a CARB one, won't be too restrictive. If it's non-CARB, it's not California grade, and no telling what it's got inside.

RwP
 

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Discussion Starter · #5 ·
If you follow the plug wires, they go to a distributor in the back. That has a cap and a rotor inside. This distributes the spark to each cylinder (hence the name).

Before you worry about anything else, do the filters, the cap, the rotor, the plug wires, and the plugs in order to verify it's not just having problems firing properly.

One other choice, if you just changed the cat, and it was coming apart, may be pluggage in the muffler; since I'm fond of glass packs, my take would be to cut the old muffler out and replace it with a glass pack :p but you may want to check back pressure first to make sure it's not plugged.

The California cat, if it's a CARB one, won't be too restrictive. If it's non-CARB, it's not California grade, and no telling what it's got inside.

RwP
Thanks Ralph, Sorry it took so long for me to acknowledge your reply.
Sure enough, my switch/relief valve melted on the upstream side. Amateur mechanic said it was due to a blockage in the catalytic converter.

I then replaced my catalytic converter yet again. This time with a Magna Flow and I’m about to install a junk-yard switch/relief valve.

Truck starts right up and idles well but I still have that jerking transmission problem and at times I step on the gas and my car barely moves until it jolts into the next gear smh…This old Dakota thing is exhausting lol

Is there a clog caused by a bad weld somewhere?
 
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