sputters/ cuts in and out at highway speeds

[bradhayd]

I have a 99 cavalier with a 2.2 and 3 speed auto. It started sputtering at 70 mph plus. I can still accelerate (still sputters) and let off the gas. (kind of like air bubbles) The other thing I noticed is the temperature gauge goes down towards cool when the engine cuts out then goes back up or at least tries too. The sputtering starts after about 10 miles on the highway in the morning and as soon as i get on it in the afternoon. It is about 4 miles for me to get to the highway. I can drive all over under 70mph and no problems. I have had the ignition coils and module checked. The module tested bad and I put a new one on and still have the problem. Any help would be greatly appreciated!

[Helmuth48]

OK...help us here....Is the CEL (Check Engine Light) on??? If yes, get the code read and report back....

Cheers Mate, JzJzz

[bradhayd]

Sorry forgot to mention the check engine light is not on. The only thing on the dash is the temperature gauge acting funny. The car starts fine, runs under 70 fine. Today it only did it over 75 mph on the way to work 47 miles each way. Doesn't matter if its a smooth or bumpy part of the highway either.

[Helmuth48]

OK...NO code....but have it Scanned anyway....Sometime a CEL or MIL will not set until the problem has repeated it exact conditon several time.
AutoZone or Advance will Scan for free. Hand Scanner are cheap, I saw at Advance one for about 50.00....well worth the $$$ if you are a gearhead!! If not....use it to check your friends ODB-II system..charge 10.00 or 6 pack and it will pay for itself in a hurry.

Check the connection at the ETC...it is good, no corrosion. If you got the cash...replace the sender. I believe it is a dual output, reads the temp of the engine and provides a signal to the computer.

Cheers Mate....JzJzz...the Man from Down Under is at the Pub !!!!