1988 Toronado runs rough

Hello!

I am from Germany and have a big problem with my car. Let me give you an overview:

I bought this 1988 Oldsmobile Toronado some month ago. The car didn't run because of a shot fuel pump (the car was stored in a garage for about 7 years) - the pump was easy to replace. But after the engine runs the real problems began.

It has a very rough idle also the rattle of the timing chain was noise, i replaced the chain and gears. Also I replaced the camshaft sensor and replaced the magnet sitting on the upper gear.

The car starts good when cold, overall when the car is cold it runs very smooth. But at about 72 degrees Celsius the car starts to idle very rough, you feel the vibration when you sit inside the car.

So far I replaced following:

- fuel pump

- fuel filter

- air filter

- oil and oil filter

- Timing chain and gears

- Camshaft position sensor incl. magnet

- spark wires and spark plugs

- PCV

I also checked and cleaning following:

- IAC (also cleaned)

- MAF (also cleaned)

- TPS (says 0.42 volt in normal, and 4.xx when WOT)

- interchanged coil pack and ICM with my 1992 Park Avenue (daily driver) for testing

- tested the EGR with onboard diagnostic, 1 (out of 3) solenoids isn't clicking, but there's no error code do far - could it be shot?

I also cleaned the complete throttle body and checked for vacuum leaks (sprayed the engine with 'brake cleaner' to see if it changes idling when spraying into a leak).

Do you guys have any tipps?

Thank you very much!

Florian

But at about 72 degrees Celsius the car starts to idle very rough, /QUOTE]

Do you mean at a COOLANT temp of 72 C (that's 160 F) the car starts to idle rough? Sounds like a bad coolant temp sensor. Also, if the car has been sitting for 7 years, consider changing the injectors, or at least having them cleaned.

But at about 72 degrees Celsius the car starts to idle very rough, /QUOTE]

Do you mean at a COOLANT temp of 72 C (that's 160 F) the car starts to idle rough? Sounds like a bad coolant temp sensor. Also, if the car has been sitting for 7 years, consider changing the injectors, or at least having them cleaned.

Yes, I mean coolant temperature. Changed coolant temp sensor as well. I'll check the injectors, but as said it has oy a big idle. When I rev at about 1500 RPM the car runs very smooth.

Yes, I mean coolant temperature. Changed coolant temp sensor as well. I'll check the injectors, but as said it has oy a big idle. When I rev at about 1500 RPM the car runs very smooth.

I cleaned the fuel injectors today, also I changed the o-rings. They where very clean, maybe because I put some Techron fuel system cleaner into the car.

Tomorrow I will also check compression on the cylinders. Because the car sat for 7 years the valves can have rust which may result in rough idle.

One thing I want to note: the car gives me a hard bang when I gear into reverse (doesn't make this when in put it in drive) - nevermind if the car is cold or hot. Has this a relation to my rough idle? What do you think? Heard of problems with the torque converter solenoid... just an idea. :-)

The infamous double-clunk into reverse. They were known for that when they were new-ish. 440T-4 transmission. We worked on alot of those transmissions back when I worked for the local Olds dealer. Toros, 88s, 98s and Cutlass Cieras. Don't remember what caused the double-clunk. My mother's Ciera had that and we had it repaired under warranty. I don't believe it has anything to do with the TC solenoid, though. Usually what happens with those is they don't release the converter lock-up and the car stalls when it comes to stop.

Paul

The infamous double-clunk into reverse. They were known for that when they were new-ish. 440T-4 transmission. We worked on alot of those transmissions back when I worked for the local Olds dealer. Toros, 88s, 98s and Cutlass Cieras. Don't remember what caused the double-clunk. My mother's Ciera had that and we had it repaired under warranty. I don't believe it has anything to do with the TC solenoid, though. Usually what happens with those is they don't release the converter lock-up and the car stalls when it comes to stop.

Paul

Hello Paul,

Thank you for your answer! Do you think it's a easy fix or must I disassembly the complete transmission? :-)

On Friday I changed the EGR and the ICM (also want to change the ignition coils, but the package is stuck anywhere between USA and Germany...). But I put the ignition coil from my Park Avenue for testing. Also I cleaned the fuel injectors.

And guess what: the car is still idling rough... that really makes me crazy.

As said when the car is cold it runs very smooth, when it warms up (about 45 degrees Celsius) you feel a little vibration, at 72 degrees Celsius (car goes in closed loop) you feel the vibration very strong. Because I had no idea what to do I started to drive the car and give him some WOTs (hit him to about 50 km/h), after that the car rans very fine.

I thought the problem was gone, so I restarted the car and rough idle is back again. Mh. What has the WOT done?

Also very strange: the fan doesn't stop to cool down the car, as I know operating temp is about 90 degrees Celsius, but the fan cooled down the car to about 66 degrees Celsius. I checked the coolant temp reading while the car is running: gauge says 66 degrees Celsius and the coolant temperature sensor (changed the sensor already) for the ECM also says 66 degrees Celsius.

I absolutely don't know what to do...

I want to sum up what I already have done so far:

- IAC (checked regarding Haynes manual and cleaned)

- TPS (checked regarding Haynes manual)

- MAF (checked regarding Haynes manual and cleaned)

- O2 sensor (changed)

- throttle body (cleaned)

- air filter (changed)

- ICM and ignition coil (new ICM, and ignition coil from Park Avenue)

- spark wires (changed)

- spark plugs (changed with NGK 0.60 gap)

- coolant temperature sensor (changed)

- fuel pump (changed)

- fuel filter (changed)

- fuel injectors (checked (15.2 - 15.4 Ohms) and cleaned)

- EGR (changed)

- timing chain, gears and damper (changed)

- camshaft position sensor (changed including magnet on camshaft gear)

- cleaned ground wires under hood

- checked for vacuum leaks (also sprayed engine with 'brake cleaner' (don't know the English word for that but I think you know)

- changed engine oil, transmission oil and coolant

I get no error codes. What could it be?

I thank you very much for any help!

Florian

Maybe the gas tank fuel filter is plugged up from 7 years soaking in old gas? Ron

Maybe the gas tank fuel filter is plugged up from 7 years soaking in old gas? Ron

Hello,

already changed the fuel filter. I don't think that it is clogged.

Maybe you guys need the parameters from the diagnostic mode? Like 'CROSS CTS ED18' and so on.

Sounds like the car isn't fully warming up .Probably needs a thermostat. The fans won't overcool the engine if the thermostat is working properly. The rough idle may be caused by a leaking or stuck EGR valve. You could test for this by removing the EGR and making some type of plug or plate to seal the EGR holes. If the idle smoothes out get an EGR valve. If not you have eliminated the EGR as the problem.

Sounds like the car isn't fully warming up .Probably needs a thermostat. The fans won't overcool the engine if the thermostat is working properly. The rough idle may be caused by a leaking or stuck EGR valve. You could test for this by removing the EGR and making some type of plug or plate to seal the EGR holes. If the idle smoothes out get an EGR valve. If not you have eliminated the EGR as the problem.

It's warming up very good. Unfortunately the fan is cooling the car down. It doesn't shut off as it should, it's always blowing when it goes on for the first time. Relais maybe?

The EGR is completely new.

Maybe the ECU?