89 bonneville strange problem

[Billy J]

Bad oil pressure switch ? bad relay passenger side under dash. No oil pressure when cold so the fuel pump want stay on until it gets about 30 psi oil pressure. I jumped the relay to complete the circuit and the pump stays on when the key is on. only bad thing is , the motor will run with no oil. So when cold no oil pressure until you turn it over long enough to build pressure and turn on pump. After it warms up, the oil is thinner and gets to the oil pressure switch faster therefore starting faster. PEACE !

[Tech II]

Wow.....oil pressure switch has nothing to do with oil pressure......the oil pressure switch is only a "backup", to the f/p relay........symptom for a bad relay, is a long extended crank before starting.......

The idle is smooth now. But it still is rough running when cold. I'm wondering if it's a vacuum issue at this point. I'm thinking maybe egr or iac or fuel regulator. Above have any thoughts on this? Thanks.

Spray engine with carb cleaner to check for vac leak.....check f/p regulator vac line for fuel......also need a scan tool to read coolant data......if reading warm when actually cold, it will run lean....

Losing coolant? Last tuneup?

[Biomistake]

So I think it was just badly needing new plugs and wires. I installed some on friday and it basically starts right up. I also did clean up the throttle body with carb cleaner. Butterfly valve and iac port.

I just have one more persistent problem. After driving for awhile the idle will creep up and stay high. It's annoying and makes breaking hard since the engine is almost racing.No codes are being thrown. Any idea on this one?

[caboclo3]

By cleaning the IAC port and butterfly ,you may have caused the IAC to send different values back to the engine computer. For the computer to relearn with the new value, I would suggest disconnecting battery terminal for several hours, then reconnect ,start and drive the car for 10-15 miles normally. That may take care of the fast idle after warmup issue. Good luck.

[Biomistake]

Thanks for the suggestion but this is an ongoing problem. It actually stopped for a few days but has come back. Nowhere as near a bad though. It was super high before. Now its just high.
Before the idle was so high it would pull off from a red light after releasing the brakes on it's own. Now it's not driving itself, but high enough to make breaking hard.

[Tech II]

If carb cleaner detected no vac leak, then you need a scan tool on this to read data, especially, IAC counts....

[Biomistake]

Dang. I don't have one and don't anyone with one. Guess that means I'll have to turn it in to a mechanic. That sucks. Lol

[Biomistake]

Just to let you all know, I broke down and got a new ecm from a u pull it place and installed it in the bonneville. The high idle is gone now. Whoo hoo! Score one for the little guy. The old one was a remanufactured one from napa that was replaced in either 2000 or 2001. The one I replaced it with us an original oem one.

Something else that has been bothering me though. Since I lay changed my plugs and wires, upon alteration the engine kind of bucks. Only on acceleration. Like it wants to kill. Sometimes lightly, like a hiccup. Sometimes super heavy and will make the belt chirp for a sec. Any thoughts on this problem? Thanks.