96 lt4 will not rev past 3200
 

96 LT$ / 6 speed will not raise above 3200 either in neutral or on the road under load. car starts and runs fine to that point. did replace frame mt fuel filter last weekend with no change. any help on this will be appreciated. thanks!!!

Does it run properly until you get to the 3200 number ??

Your distributor is probably about to konk out once and for all .

and? What happens at 3200, does it break up, shut off, or just stay there and act fine?

Could also be a plugged cat. Tape a fuel pressure gauge to the winshield to rule out fuel could also be a leaky pulsater. How are your o2s?

at 3200 the engine just stays there and acts normal !! rpm might get to 3500 when really warm but no higher. thanks

basically the engine just stays there and runs OK but will not climb higher

This is a new problem or the car has been this way since purchase? This is a OBD2 car and I'd think you should/might have an SES light for nearly any issue that would create this run condition. Do you have SES on? At KEY ON - ENGINE OFF do you have an SES for the bulb check?

Please answer WVZR-1's post as we need that information first. However, if what you say is all there is then it sounds to me that you have a throttle cable/linkage issue or throttle body issue. I am not aware of any reason a motor would rev to a specific RPM and not go any higher.

If it were fuel related (injectors or fuel pump), then the engine would try to rev as high as it could and then cough and sputter randomly as it ran out of fuel.

If it were spark related (opti or plugs), then it would be similar to fuel issues but usually be less random in nature but not act as a rev limiter. Sometimes you would have pre or post detonation if the distributor (opti) was the issue.

This is why I believe the issue is a fuel and air metering issue. It could still be any of the two above but since you say the motor stops at a specific RPM and will go no higher leads me to believe the issue is as stated above.

EDIT: After thinking a little more, it could be a few other sensors going bad/unplugged. I don't have my books at easy reach at the moment but if you are still have problems when I return this evening I will dig them out and see what I can find. I will need more information and details of the problem so I can narrow down in the book.

this is something new, 2 weeks ago. car only has 63,000 mi and ran well up till now !! thanks

I'm with ant on this. It sounds like your exhaust is plugged.

I would guess cat too, it is an odd issue. Do you notice any other changes, does it run hotter or have more heat in the interior? Look at your TB too, make sure it is opening all the way. If you are in 3rd at 3200, and drop in into 2nd, it stays at 3200?

You didn't answer the questions regarding SES?

Opti?

NOT a mechanic, but I'll throw it out there.

:iagree:

I know this is a old post but I'm having almost the exact same thing. I have a 89 C4 with 49k original miles. Tested good fuel pressure tonight so I'm wondering if it is the converter? I was also wondering how long the factory valve springs can stay good. I had a 427 in HS that did the same thing till I changed the valve springs then it ran like a champ. Please post any update on what you may have found was the cause of your problem.

:iagree:
I would like to know also if there is a engine light or a code that might trigger a "limp home mode" condition.

No codes or anything with mine. Just won't rev rps past 3500 or so.

I know its a couple of months now and maybe you found the problem if not here is my experience. My wifes Monte Carlo SS had the same problem I could hold it to the floor and it was like having a rev limiter on at 2800 RPM. Disconnected the exhaust before the cats and it revved like normal just a little louder lol. I would do an easy cat check and just disconnect the exhaust at the end of the manifolds and see if the rpm's come back. If it does bad cats. Keep us posted.
BNB08

use a digital temperatur gun to measure the temp (point it) before the cat and after the vat. compare both sides, you will see if its your problem this way.

What a great test VikingTrad3r!!!


Car Temp.... warming up 175 deg at dash and engine block
Passenger Exhaust before pre converter 190 deg
Driver Exhaust before pre converter 500 deg
In front of cad converter 400 deg
rear of converter 220-240 deg


What does a Pre-Converter do? I would guess mine and the Catalytic converter may be bad after almost 30 years! LoL