1997 Southwind engine problems

[Jim 1959]

Hello I hope someone has suggestions I have a 1997 Southwind Storm with
P-30 Chassis Chev 454 with throttle body fuel injection it only has 30,000 original miles it sat for a few years not being started or driven
i drove it from sisters house in California to Baltimore last year .It runs ok but only after the engine temp reaches 210 degrees The problem that Im having is when its cold i have to keep the engine rpms up high until the temp gets to 210deg as it gets close to temp it starts to run and idle better when it hits 210deg it will idle ok and then i can drive it

I was told by Mechanics' that that year was a transition year for CPU and throttle body fuel system I did have the following work done and alot more but still having the same problem
Gas tank and fuel system flushed and cleaned
rebuilt throttle body, full tune up,all new engine Sensors
Everyone is Baffled Thanks for any suggestions Jim

[Unplanned Tourist]

Just wondering if injectors are not feeding enough fuel?

Also it could be the PCM is getting a poor signal for engine temp and not richening it up for the cold running. Thinks it's at operating temp all the time.

[GypsyR]

I've had a defective GM coolant temp sensor before that read hot all the time. It got to the point where the car wouldn't start without some carb cleaner or starting fluid. It also ran crappy until it actually came up to the temperature that the sensor was telling the PCM it was.
This case doesn't precisely match those symptoms but it sure sounds like the PCM for some reason isn't feeding the engine a fuel mixture rich enough until it gets warm and doesn't need the rich mixture anymore. I'd be all about checking codes and more importantly, an OBD datastream to see what the PCM sees when the engine is cold. OBD I's have that, just less info to look at than OBD II's. Then when you see an IAT sensor reporting 200F when you know darn well it's 38F outside it's too easy. IE, one of your temp sensors would be my first suspect. Second I think I've be studying the MAP sensor and then the TPS. And keeping an open mind for shorted O2 sensors or anything else.
And by the way, NEW to mechanics stands for "Never Ever Worked". You can't quite count on whatever new sensors you bought being better than the old ones. I once went through four different brand new oil pressure sensors before I got one that was reasonably well calibrated.

I can't fix it over the internet. I am just relating which way my troubleshooting would go based on the info you provided.

[arcaguy]

I'm with the 2 posters above. My first thought when I read your post is that the enrichment function is not working correctly. I think GypsyR is on the right track there is some sensor that is not sending good information to the computer. I would try what he said about following the data stream of the various sensors. As a mechanic friend of mine used to say "New don't mean good." Good luck.

[Jim 1959]

Thanks to all Im to this RV life/form an old RV er and have always worked on my own RV rigs of all kinds but this problem is the first time that no one has been able to fix the problem I received this RV from my sister she bought new and never had any problems with it until health problems stopped here from using it
the last Mechanic did replace the injectors,temp sender you all have been alot of help I will work on your suggestions get get back to you all Thanks again Happy RVing

[GypsyR]

As difficult as it is to believe a professional repair shop in 2022 has no ability to figure this one out or is lacking the proper diagnostic equipment to work on a vehicle of this vintage, they exist. There are those bound and determined to just guess and throw parts at issues until they accidentally replace the correct part. Or so they hope. Sounds like you've already had it at such a shop. Some cities have "mobile diagnostic techs" that DO have the equipment and make their living going to to such shops when they have run out of parts to swap and are forced to find out what the actual problem is. By paying someone else. Such a person generally won't repair the issue, they just find it. Might be worth trying to find if you have one of those around. One nice thing is they don't mind coming to you, it's what they do.

[cadillac_al]

Is there a service engine light on? Did anybody scan for codes yet? I don't understand replacing parts without trying OBD first.

[Soppy]

There should be 2 coolant temperature sensors on your engine. One is for the gauge and the other is for the ECM. When first started , the engine runs in "open loop" and only uses the coolant temp , throttle position and MAP/MAF sensors. Once the oxygen sensor heats up (after a couple of minutes) the engine will go into "closed loop".
Your best bet is to get a scanner or computer program (such as "Tuner Pro RT") that you can monitor the live data and actually see what is happening.

[98fleetwood]

I feel bad for you. I sure hope you are not paying someone to replace good parts. Your mechanic needs a good scan tool. The good scanners you can read in real time what your sensors are reading. In your case the "old school" term would be, "The choke" is not working. Being all computerized this has to be diagnosed with a scanner..
Best of luck

[GypsyR]

Worst part is that on this vehicle a 25 year old antiquated and outdated scanner can read all the necessary codes and data every bit as well as a brand new top of the line one.