Surging sputtering issue

Tiny
JUSTIN HALL
  • MEMBER
  • 1995 CHEVROLET SILVERADO
  • V8
  • 4WD
  • AUTOMATIC
  • 170,000 MILES
I’m having issues figuring out what’s wrong. When I start the truck in the morning it runs and drives just fine but as it starts to reach normal operation temperatures it acts weird. When I come to a stop and then start to go again it almost feels like it’s choking itself out or not firing or bogging. It doesn’t do this every time but occasionally will. When it does do it if you accelerate a little more it come out of it and drives fine. Any suggestions would be appreciated.
Do you
have the same problem?
Yes
No
Wednesday, February 6th, 2019 AT 11:30 AM

12 Replies

Tiny
STEVE W.
  • EXPERT
Hello and welcome to 2CarPros. Being a 1995 you cannot easily scan it for codes, however I would suspect a faulty coolant temperature sensor or the wiring to it being it isn't a constant problem. Your vehicle uses two sensors, one goes to the ECM and the other to the gauge in the dash.
GM # 15326386 is the ECM sensor. It screws into the intake manifold next to the thermostat housing. A trick to changing it out without draining the coolant is to have a cold engine. Start removing the sensor until it is almost fully out. Now squeeze the top radiator hose hard. Release it and as soon as you do remove the sensor and screw the new one in, if needed a helper on the hose can make it much easier. Squeezing then releasing the hose will create a small vacuum inside the engine for a couple seconds, that is usually enough time to swap the sensor and only get a tiny amount of coolant out of the system.

You can test the sensor first if you have a multi-meter. Simply check it's resistance using the table I posted. However, you would need it to be acting up while this happens to be sure it's the part that's failing.

Another option would be to find a shop with an older scan tool that can read the data from the PCM and see what it shows while it is acting up. However that could take a while unless it always acts up.

I would also look at the connector real close, corrosion or damage can cause a lot of problems, many times more than failed parts.
Was this
answer
helpful?
Yes
No
Wednesday, February 6th, 2019 AT 6:20 PM
Tiny
JUSTIN HALL
  • MEMBER
Hello so I have recently done a tune up on the motor and I noticed that temp sensor was broken so I replaced it once already is it possible I just have a faulty sensor? Also I know there is another temp sensor on the driver side of the block that I have not replaced. Would that one effect anything? Also I have started it on a cold morning and noticed an exhaust leak on the back side of the manifold and I realized the rear bolt was broken off could this effect anything? The leak isn t major and most times I can t even hear the noise. I do have a video of it running when it acts up if you d like me to attach it?
Was this
answer
helpful?
Yes
No
Thursday, February 7th, 2019 AT 11:05 AM
Tiny
STEVE W.
  • EXPERT
I would check the wiring to the sensor. Being it was broke off the internal pins may not be making good contact and causing faulty readings.
The other sensor is for the dash gauge, if it is reading OK, the sensor is OK.
The exhaust leak can cause the O2 sensor on that bank to read a lean condition and add more fuel. As well.
We always like videos.
Was this
answer
helpful?
Yes
No
Thursday, February 7th, 2019 AT 5:21 PM
Tiny
JUSTIN HALL
  • MEMBER
Alright, I ll check it out. And my only o2 sensor is a three wire one on the right bank there isn't even wiring for one in the left bank (it is dual straight pipes with mufflers).
Was this
answer
helpful?
Yes
No
Friday, February 8th, 2019 AT 11:52 AM
Tiny
JUSTIN HALL
  • MEMBER
Here is the video of it doing it. I am pressing slightly on the gas.
Was this
answer
helpful?
Yes
No
Friday, February 8th, 2019 AT 11:57 AM
Tiny
STEVE W.
  • EXPERT
What other modifications are on the truck? It would have only had one O2 sensor. Plus a MAP, throttle position and coolant temperature. Does it idle okay?
Was this
answer
helpful?
Yes
No
Friday, February 8th, 2019 AT 8:04 PM
Tiny
JUSTIN HALL
  • MEMBER
Nope just the dual straight pipes. Yes it idles perfectly, good oil pressure, runs good when driving. It s just does it when I go from a stop to take off.
Was this
answer
helpful?
Yes
No
Saturday, February 9th, 2019 AT 9:56 AM
Tiny
KEN
  • ADMIN
Hello,

It looks like the TPS sensor is not working right but to be sure lets run the codes. this guide will help us:

https://www.2carpros.com/articles/buick-cadillac-chevy-gmc-oldsmobile-pontiac-gm-1983-1995-obd1-code-definitions-and-retrieval-method

Please run down this guide and report back.
Was this
answer
helpful?
Yes
No
Monday, February 11th, 2019 AT 11:10 AM
Tiny
STEVE W.
  • EXPERT
Did this all start after the tune up? Or was this the reason for the tune up and it didn't change? What did you do for a tune up?
Was this
answer
helpful?
Yes
No
Monday, February 11th, 2019 AT 2:08 PM
Tiny
JUSTIN HALL
  • MEMBER
It started after the tune up. I just did a standard tune up. Checked cap and rotor cleaned them up even though they were good. Plugs, oil and filter, I did flush the coolant system also, replaced that coolant temperature sensor and that s about all I can think of. I did try cleaning the contacts of the plug on the temperature sensor and it didn t seam to help. I can try replacing the TPS sensor and see what that does. Also, I pulled codes and all I got was o2 sensor.
Was this
answer
helpful?
Yes
No
Tuesday, February 12th, 2019 AT 1:45 PM
Tiny
KEN
  • ADMIN
I was going to say coolant sensor but you did that. Did you manage to run the codes?
Was this
answer
helpful?
Yes
No
Wednesday, February 13th, 2019 AT 10:51 AM
Tiny
STEVE W.
  • EXPERT
An O2 sensor could cause problems, but usually that would occur all the time not just at a part throttle situation, however it would depend on what it was actually doing. As the issue started after the tune up, I would just go over what you did, just to be sure that a connector pin didn't get bent or another item like a vacuum line or wire didn't get knocked loose while you were working. BTDT before.
Was this
answer
helpful?
Yes
No
Wednesday, February 13th, 2019 AT 1:09 PM

Please login or register to post a reply.

Recommended Guides