wysiwigs

My Tahoe seemed to be running good considering it's age, then it seems all in one day I started to have problems getting it to keep running at start up. Once it does start, I have to keep the RPM's around 2000 to keep it running and it misses terribly. Carbon builds up on tailpipe and it smokes, but not black or pure white smoke. Some condensation comes out of the tailpipe, but I think this is normal condensation. I'm in Michigan, cold temps right now in an unheated garage. Once it has warmed up awhile it seems to idle okay, not perfect....but it doesn't die out either. After it's been warmed up, if I go out to start it again I have to push the pedal to the floor for it to start. That works every time, but it goes to that rough running condition again for a couple of minutes. Once I get going down the road with it, it seems to run okay and I don't see any drop in the RPM's or any signs of low power. I did notice a couple of times, maybe my imagination...but a slight surge in power and a possible problem with the shifting seeming kind of slower than I remember. This could be my imagination, but just in case...I thought I need to mention that. Oh, and horrible gas mileage too.

Here are the things I've done thus far: I checked antifreeze and oil for any signs of blown head gasket, I see nothing of concern there. The moisture from the tailpipe seems clear and has zero smell or greasiness to it. The air cleaner looks fine, could need replacing but it's not in any way a problem as is. The plugs/wires/rotor cap are all new as of about 4 months ago. I bought some CRC throttle body cleaner, used that yesterday and there is no improvement. I have purchased a new Throttle Position Sensor and will be installing that tomorrow, as it seems to be a common issue and might be the cause. I dunno.....
The catalytic converter is not plugged, so that's not the problem.

Can anyone give some suggestions based on the symptoms I have described? I have someone coming over this weekend with a diagnostic code unit, hopefully. It MIGHT tell us something useful, But what did we do before those units came out? We diagnosed on our own. I don't want to get tons of money into things that are not the cause of this particular issue. There are lots of things that need to be fixed on this old baby, but first I need it to run decently.

Also, I need to be absolutely sure here on this question, because I get varied results when I research it, but does the 1995 have an MAS? (mass air sensor), or does it have an MAP? And where would I locate either?

Thanks so much! I'm having to do a ride share to work right now and it's kind of iffy day to day. I don't want to get stranded in sub zero temps with the Tahoe, and it's a real possibility right now.

Edit: I also added STP oil treatment to it about a week ago.
Edit again: Possible Idle Air Control Valve? If so, where is that located?

Additional information on what's been done to the truck: My major problem with this truck this year started with a blown return fuel line. It had rusted a hole in it. The line had been spliced and a piece of high pressure hose clamped on. This was supposed to be a temporary fix until I could afford to get the line replaced. My first thought when I began having the starting problems was maybe there was something wrong with that temporary fix somehow, because it was close in timing on when the starting problem began. Not right away, but withing a couple of weeks. I questioned whether maybe this fix had become an issue when my trouble first started, was told no.....but apparently it was rethought and today I was told to look for a possible pinch or kink in it. I'm going to look at that tomorrow. So, a pinched return fuel line....could this be the cause of the issues described?

There is no money to have this into a shop to replace that line or anything else major right now. I mean NO money. LOL I have to try to get this going on my own until I can save up for proper line replacements, etc.

Frank3

I would start with the scan to see if there are any codes. Also look at the data to see of the coolant sensor is reading reasonable close to what the coolant temp is.

Suburban Dude

95 was before the days of MAS or MAP. That TPS should help. Let us know if that that worked.

SD

wysiwigs

First of all, thank you to Michigan salt roads and the resulting rust buckets that occur from it. LOL

I could not get diagnostic coding done this weekend, weather and work schedules got in the way of having the code unit here. SO, I got under the truck and looked over that fuel line....coincidentally overnight a small gas leak is going on right in the same area as where it was repaired. The line that was repaired with rubber hose was kinked/bent pretty bad at the end from trying to tuck it up on top of the frame where it belonged. Very little area for any fuel to get through that, if any. The hose was too long and caused it to bend forward and kink. This is what I had thought when the problem first began, but I kept getting steered in other directions.

The hose had a split in it and bubbled at the kinked area. I am going to fix that, a shorter hose and make sure it fits without bending or kinking. The other fuel line appears to have a leak at the clamp, so I will have to fix that one too. Thank the lord they are both in the same area and I can get to them. I believe this is the main issue, so wish me luck. I did go ahead and replace the TPS this morning, that went fairly easy....except .....the new TPS does not include the little rubber gasket thing (I am not sure what that is called) that goes on the inside. I did not notice this until after I installed the new one and decided to check out the old one thoroughly. I had to remove the new one again and insert that rubber thing. Grrrr.......
Hopefully this is the short term fix and driveable until I can afford to pay someone to replace that line correctly. The gas tank will have to be dropped to do that, and at $75.00 per hour minimum plus parts for a certified mechanic...it's just not in the realm of reality right now. ;-)
Thank you for letting me know on the MAS!

Another update. I took off the kinked hose and discovered the end of the line where it had been cut originally was pretty much crushed with metal blocking the opening. I'm surprised any gas was getting through there at all, makes sense it was putting a lot of pressure on the hose clamp area trying to go somewhere and finally broke through. The clamps were overly tightened as well, which caused the split. I'll start it tomorrow and hope I fixed it. I need to thaw out. Oh, what I wouldn't give for a heated garage. LOL I keep trying to be wonder woman here, and keep getting reminded that I am not. Ha ha ha ha.....