I have a 1995 olds 98 Regency elite, no supercharger, cleaned the mass airflow sensor, replaced fuel filter, checked for vacuum leaks and found none. Put a new mass airflow sensor on it, and it made no difference whatsoever. I Put a new mass airflow sensor on it and it made no difference whatsoever. It’* barely able to sustain 65 miles an hour on the interstate, especially going up a hill has to downshift just to hold it. Between 3 to 3500 RPM max and then it sounds like popcorn popping. Very doggy and weak. No codes no check engine light.

I would start by checking fuel pressure. Let us know what it is . . .

- . . . key on engine stopped
- . . . engine idling like normal
- . . . engine idling like normal and the vacuum line for the fuel pressure regulator disconnected and plugged

How many miles on it?

How many miles have you owned it?

70,000

Thank you for the reply! I will try to check the fuel pressure this afternoon.

Sounds like the fuel filter is plugging up.
I would expect the CEL and a lean code

Also, condition of the air filter?

thank you very much for your input! I actually had to replace the fuel filter just over a week ago and it did seem to increase the performance. I’m thinking that the fuel pump is week.

I looked all over the place and couldn’t find a fuel pressure gauge, so I have one coming to me later today. I will definitely post the results on here! Thank you so much!

What you may need to do is to watch it while under load. We used a 6 foot one and put it under the wiper arm to the windshield. They may read fine until you start going uphill and then you could watch the weak pump fizzle out.

[QUOTE=CathedralCub;1646126]I would start by checking fuel pressure. Let us know what it is . . .

- . . . key on engine stopped initially when you turn the key on the pressure goes to 42 and drops to 36 or 38
- . . . engine idling like normal. At idle it’* at 42 psi.
- . . . engine idling like normal and the vacuum line for the fuel pressure regulator disconnected and plugged. I didn’t do this! I knew there was another step.🤦‍♂️

However, when I started to throttle up the engine at around 1800 to 2000 RPMs, the pressure went up to about 48 almost 50. It was really weird.


Idol pressure

Pressure when the key is first turned on


How many miles on it? 138,000

How many miles have you owned it? 60,000

I think you ave a restricted exhaust or weak fuel pump. Check back pressure or just do this. Watch the fuel pressure while power braking. Keep it at converter stall until it starts running bad. Does the fuel pressure hold while the engine loses power? If so, it'* a plugged exhaust. If not, the pump is bad.