Need help! 2005 Cadillac CTS

[bigbadchev84]

The wife Was telling me the other day when she went to start her car it shook really bad and died, This happened 3 times in a row. 4th try she kept her foot on the gas and it cleared up and ran just like normal for the rest of the day.

This morning she had parked behind my work truck, it was about 15 degrees outside and I jumped into it to move it. Started right up and died instantly, 2nd try with my foot on the gas peddle, fires up shakes violently and dies, 3rd time same thing, 4th try I got it to stay running but was shaking pretty bad.

Just got home and the thing fired right up and idling smooth, about 35 degrees outside, hasent been driven all day.

My first thoughts are coolant temp sensor, It is not throwing any codes so I am shooting from the hip. Is there anything else I should be checking for?

 

[fubar_k5]

I dont know what motor is in it but my moms impala with a 3.4 would start hard and rough idle for the first couple seconds and would spit and sputter on take off until it was fully warmed up. I ended up cleaning the maf sensor and put on a new air filter yesterday and has been doing good so far.

 

[bigbadchev84]

It has the 3.6 liter. Google search of the symptoms didnt really tell me much. Will the MAF care if it is cold outside? This is the only time the symptoms occur. We kept it in the garage last night and all was well this morning.

 

[dhcomp]

I would think the shaking is really low RPMs, and could be caused by fuel delivery.

Runs fine otherwise?

I'd be guessing fuel filter/pump....

 

[79rustyk10]

I was thinking a fuel pressure issue as well.

 

[Blue85]

MAF works based on a heated wire, so outside temp could make a difference.

Or it could be missing on certain cylinders to make it shake.

 

[bigbadchev84]

The thing runs flawlessly other than the issues that popped up twice now with it shaking/starting. Parked in the garage again and no issues. I was really hoping a code would have popped up so I had something to go with. I will try parking it outside friday night and check it saturday morning.

The wife leaves for work at 5am and this has a potenitial for a huge headache for me to deal with before I have to leave to work.

 

[eagle mark]

Did you read codes or just going by CEL? Some codes are stored and will not set CEL. Some codes need 2 trips to set code.

 

[bandit408]

sounds like the injectors are leaking or the ignition system needs some attention. How many miles are on it? I haven't seen many of those go the 100,000 miles before plugs need to be changed. Usually we see issues around the 85k mark in the cold weather around here.

 

[bigbadchev84]

There are no codes on it, It has 101k miles, spark plugs where replaced at 95k along with all the belts, filters etc

 

[bandit408]

Well that rules out the ignition. Sounds like the fuel injectors are leaking after you shut the engine off. I actually made valves that I can hook up to the fuel rail on the feed and return. This way you can see if it is the fuel pressure regulator leaking or the injectors. If you cant get those (I made mine from parts at the auto parts store and Home Depot) at least pull the vacuum line off the fuel pressure regulator to see if the diaphragm is leaking fuel directly to the intake.