weak start and real loss of power

[Craig]

Hello,

I have an 89' sho. I got it in 1990 with about 10000 miles on it. It has about 150K now. I work out of my home and am sort of local in my driving. I drive the car daily at least a little and drive easy. I'm 68 years old.

I have 2 problems that may have been there for awhile (and may be related), but have gotten worse. Problem 1 is a weak start. I turn the key and it starts weak and stutters a little in the low RPM range and then recovers to the normal tack (8900) setpoint. If I try to go before the car warms up, it will die and require that I push the accelerator to floor to start it, but it does start. When the car has warmed up, it runs OK. Problem 2 is that while it runs OK, there has been a major loss in power. The top speed is maybe 80MPH down hill with a tail wind. When I go up a hill in 4th, I can lose 10 MPH. The gas mileage is also real bad. MAF, plugs and wires, and O2 sensors are new.

Any help will be appreciated. The car is in good shape in and out. I do a little restoring about every 5 years and this is a 5th year. I'm hoping to get another 50K out of this car. Please help.

Thanks,
craig tussey

 

[SHOdded]

First thing, pull codes, see what the ECU thinks it might be. Hopefully not an electrical issues, as more are popping up with the aging of these cars

How does the IAC look? Any fuel smell in the engine compartment? Does the fuel pump hold pressure or does it bleed down? Is there fuel in the vacuum line at the regulator? Compression check done? Any oil on the cam sensor, or oil leaks elsewhere? Are the grounds good? Worth checking the DIS connectors / thermal paste. Butterflies kick in at higher RPM (3500?), so you will want to make sure the actuators are working correctly also as they tend to rust over time.

Since you have already replaced maf/plugs/wires/O2 sensors, I assume you have used known good brands for those parts.

 

[SHOMON]

I am pretty sure he has posted the same thing in another section.
Under Gen1-2 emergency issues..

 

[SHOdded]

You are correct, sir!
https://shoforum.com/index.php?posts/1504372/