need some help

[94SCparkavenue]

hey guys i have a 94 S/C Park avenue.i have a few problems. when i start the car it idles anywhere from 1500-3000 rpms. with no check engine light. the check engine light comes on out of random and will shut off out of random. also it surges. from like 1000 to 700 rpms. i have tried hooking it up to a scanner but the scanner comes up error. when i shut the car off i get a bad smell of gas. anyone know what could be the problem Thanks in advance

[myfirstbonnie]

Was there any recent work done to it? When was the last tune up? Have you ever changed the O2 sensor? What scanner are you using? It would help a lot if we could find what codes are being triggered.

One place to start would be to check for a vacuum leak and make sure all the connectors are connected. (TPS, MAF, BCS, etc)

[93RedSled-SSE]

hey guys i have a 94 S/C Park avenue.i have a few problems. when i start the car it idles anywhere from 1500-3000 rpms. with no check engine light. the check engine light comes on out of random and will shut off out of random. also it surges. from like 1000 to 700 rpms. i have tried hooking it up to a scanner but the scanner comes up error. when i shut the car off i get a bad smell of gas. anyone know what could be the problem Thanks in advance

'94 & '95 were wierd years for OBD. They have OBD 1, but OBD 2 connector. It's hard to find, but an adapter is required. I have seen posts of a home made one if you are handy that way.

Without testing, using a meter or ability to read codes, the Throttle Position Sensor (TPS) is the most likely culprit for fast idles.

There is a voltage test; but I have had them pass that test and still be bad. With the engine off, I like to unhook the TPS and check/monitor resistance between its wiper arm (pin B) & pin C. With throttle closed, the resistance should be minimal. As you open the throttle, of course, the resistance increases. Then, back at idle, it should be very low. If I get a reading in the K-ohms region, then I replace it.


Re: Surging, that may be harder to pinpoint in the engine management. It would be helpful if you knew what sort of fuel pressure you have. Also, if you are familiar with the fuel pressure regulator, you might pull the vacuum hose off it and make sure there is no fuel at that fitting, which, otherwise would indicate a bad regulator.
Hope that will get you started.

[94SCparkavenue]

sorry it took so long to respond... i when to advance auto parts to have them check it because i dont have a scanner, they hooked it up and it said error.... they said it was my plug... i replaced the tps sensor about two months ago.. it has new plugs and wires. and it still surges and has a high idle

[93RedSled-SSE]

i when to advance auto parts to have them check it because i dont have a scanner, they hooked it up and it said error.... they said it was my plug... i replaced the tps sensor about two months ago.. it has new plugs and wires. and it still surges and has a high idle

'94 & '95 were wierd years for OBD. They have OBD 1, but OBD 2 connector. It's hard to find, but an adapter is required. I have seen posts of a home made one if you are handy that way.

In the absence of being able to read codes, there is a voltage check for the TPS. From the center pin to ground. Here's what it says regarding that voltage reading. "If sensor output is outside of normal range (0.33 - 0.46 volts W/closed throttle), replace sensor."