'89 Cavalier won't accelerate past ~25mph

[raymone]

1989 Cavalier Z24, 2.8L V6. Car started up fine, idles smooth, but once I hit the road and get up to about 25mph, the car jerks and wont accelerate, engine stays running but wont accelerate. As if I let off the gas pedal, but i can still hear throttle body sucking up air, so I know the throttle is working properly. No check engine light either.
Then I thought maybe the fuel pressure, checked the fuel pressure and the regulator and all working properly. Fuel filter is new and no visible leaks in the fuel lines. So I went and checked the compression in the cylinders, and all were healthy, 120-145 psi. I did notice however that one of the spark plugs was completely destroyed and there was some fuel on some of the plugs, the car is running rich by the way. I replaced the plugs and noticed the spark plug wires were not placed correctly according to the Haynes repair manual, I corrected that and now the cars runs rough and feels like its misfiring. I double checked the wires three times and I have them the way they should be according to the book.
Anyone ever encounter something like this?

 

[zora]

what do you mean the spark plug was completed destroyed, as if something hit it? Is this the way you have the wires set. Make sure the rotor is pointing to number 1 cylinder when the timing mark is at 0 in case the wires in the cap have been moved.

http://www.justanswer.com/chevy/1qiat-firing-order-2-8l-chevy-engine.html

 

[raymone]

The insulator and insulator tip were completely gone from the plug. This ignition system has no rotor, it uses a coil pack per two cylinders. Since I last posted my thread, apologies for the late reply, I have corrected the spark plug cables, and it turned out I had two of the cables switched, which I immediately corrected, but I still have the acceleration problem. I have also checked the injectors, this vehicle has a Multi Port Fuel Injection system, and I found that the injector for the cylinder that had the blown plug was sticking in the open position. Injector was replaced and now the car runs a bit smoother, I am not getting a rich fuel mixture smell from the exhaust anymore, buuuuut... the car still wont accelerate over ~25 mph.

 

[zora]

have you tried a compression test? have you tried isolating the problem to a particular cylinder by pulling plug wire and grounding it untill you find a cylinder not firing?

 

[Chuzz]

If you have a lot of miles on it, your catalytic converter may be stopping up. Check your exhaust for blockage.

 

[raymone]

Yes, I have done a compression test, and all cylinders were healthy, I also did a spark test using an in-line spark tester and all cylinders had a healthy spark.
The catalytic is only a year old, but I still went ahead and disconnected the exhaust from the manifold and drove it, still the same.
It's just a really weird situation, it's as if something is telling the engine not to go once it hits a certain speed, once the car slows down below that speed it will let me accelerate again, but once it reaches that 'certain' speed it wont let me go. The reason I say 'certain' speed is cause me speedometer is not working so I don't know what that speed is exactly.

 

[Chuzz]

Man, that's really weird. I was thinking maybe a stuck valve or cracked piston, but since you did a compression test and got good readings, that rules that out. That one's got me stumped. I wonder if maybe you're losing fuel pressure somehow?

 

[raymone]

Man, that's really weird. I was thinking maybe a stuck valve or cracked piston, but since you did a compression test and got good readings, that rules that out. That one's got me stumped. I wonder if maybe you're losing fuel pressure somehow?

That's what I've been thinking, wondering if I can hook up the fuel pressure gauge and go for a test drive and see what happens.

 

[Chuzz]

As long as the hose is long enough, I don't see why not. Maybe you could anchor it under a windshield wiper.