James88

I am a proud second owner of a 1988 Oldsmobile Touring Sedan.

I absolutely love this American engineered vehicle.

By far the most fun to cruise, comfortable ride I've ever owned.

Recently, with 120,00 miles, the engine has stated a strange sputtering
Issue. I've researched possible issues that could be the culprit....
I've replaced the EGR valve, new O2 sensor , inspected the catalytic converter,
Cleaned the MAF sensor, new plugs, new wires, new fuel filter, had some Vaccum leaks repaired....

Unfortunately I'm not in a position to keep throwing $$ at it.

Any suggestions/assistance would be Great!!

I appreciate the quality of Craftsmanship that the engineers with Oldsmobile put into this Wonderful car. I'm hoping I Don't have to sell this TS , however, a fan of Oldsmobiles would be my best choice for finding a new good HOME...

Warmly,
James

CRUZN 66

Welcome to the site...
Did you check the fuel pump pressure? Could be a pump going bad or a plugged screen at the end of the pump???

James88

Thanks Cruzn!
The fuel pressure was measured and checked out okay. However, I forgot to mention that the engine only sputters/chokes when it's warmed up ... Could the fuel pump/ clogged screen be temperature dependent?

joe_padavano

Unlikely. A temperature-dependent problem is often caused by a bad coolant temp sensor, or associated wiring. The 1988 ECU is only OBD I, so it is very limited in capability. A bad sensor typically only sets an error code if it is grossly out of limits, such as open circuit or dead short. If the sensor is just off a little but providing believable data, it won't get flagged and the ECU will assume it is correct. This can cause a bad A/F ratio. Other potential problems are a sticky IAC, where the warm temps soften deposits on the pintle and cause it to stick. That won't set a code either. And despite injectors being downstream from it, the throttle body still gets deposits on it due to reversion in the intake tract and needs to be cleaned periodically.

James88

Hi Joe,
thanks for the insight there...

I unplugged the temperature sensor and the car idled very roughly, so I plugged it back in.... But now you have me wondering if it could be the Problem. I'm also wondering if the MAF sensor could be the issue when it warms up....

I removed te IAC Valve and cleaned it with brake cleaner and a wire brush(still sputtering/choking when warmed up..
also, My repair manual said there is a MAP Sensor(could not find it), that could cause the engine to run roughly. Any thoughts on that?

I appreciate all the assistance I can get on this most frustrating matter..

​​​​​​​

James88

Well,
I replaced the Engine coolant sensor today...

idled fine for twenty minutes, drove into town and 10 minutes later it started sputtering / choking..... Made it back home barely.

Olds64

James, since you cleaned the IAC don't forget to clean the actual throttle body as Joe mentioned. Usually it's removed with 4 bolts and there's a gasket between it and the intake.

Also, have you had the coil packs checked at an auto parts store? You could be getting bad spark.

James88

thanks 64😉

i cleaned out the Thottle body last night... Took it for a spin and after about 20 minutes of running strong, it started sputtering, only while in gear. I noticed that the RPM's did not fluctuate while sputtering, which makes me believe that it is a spark issue.... Maybe one of the three coil packs is spent. I ordered a coil pack assembly, I hope that's the fix!! After $1,000. I'll be happy to have it back on the freeway🌀