I had a simular problem with my S-10, 01, V6, 4.3. But altitude in my case was not a factor. It would idle fine, but under power it would stall or skip. A new fuel pump solved he problem. If it is the pump, consider removing the truck bed to get to the pump. I think it would be easier. Someone else out their might have additional info on that process.
Thanks for that. I’m feeling like it is fuel pump problem. Did you find it easier to remove the bed rather than removing the tank?
How full is the tank? do you have 3 friends (girlfriends don’t count) to help move the bed back? You have never stated what type of injection this vehicle has (or I missed it if you did).
Thanks, I have a 4.3 liter v6 engine 1994 Chevy S-10 LS 2wd.
It seems to run fine except going up hills especially in high altitude. In other words steep inclines. It has died and let it sit for a few minutes will start again but creep along. I would think by what you said that when it dies and then restarting it would change the parameters of the MAP sensor and it would run up the hill ok. That’s not the case however. So I wonder if I should rule out the MAP sensor. I’m edging towards a fuel pump problem. What do you think?
I can run out the tank before messing with it. I can see how nice it would be to have the bed off and not have to be on your back. I’ve pulled gas tanks before but not a bed. I will check on the injection but I believe it has a Throttle body.
I am so old we used to have to advance the timing to drive in the mountains, maybe that is a clue!
I hear ya. I remember hearing about vapor lock with carburetors but not with injectors. I’ve had similar problems with partially clogged fuel filters but I changed the filter and still does it. I’m thinking that it might be a fuel pump problem but would like to narrow it down before I go through the expense and time of changing a pump.
Well let me look what the FSM says about troubleshooting a TBI 4.3 with your symptons.
Preliminary checks: make sure both injectors are spraying,isolate by switching injector connectors,standard secondary ignition faults,Engine mechanical, valve timing,low compression,bent pushrods, worn rocker arms, broken or weak valve springs,worn camshaft lobes. Fuel sysyem, restricted fuel filter, PCM fault,Faulty PCM grounds,Faulty injector,Low fuel pressure.Restricted Fuel line, MAP sensor, restricted exhaust, well I think you get the idea there are numerous causes that I have not even listed. Any codes?
Quite a few things. I keep thinking it’s a fuel issue. I’ve changed the fuel filter but wanted to try to isolate the problem before I started changing out parts. I know you can clean a MAF sensor. Can you clean a MAP sensor? No check engine light. I shoulc check to see if any stored codes.
I removed the tank to replace the fuel pump. Before I finished the job, I realized I could have possible disconnected about 4 or 5 bolts and with a little help slide the bed over and got to the fuel pump. Since I did’t go that route, I have no way of knowing what other problems might come up useing that process. Mabe someone else out their that has tried this can add some info.
Thanks. It would be nice to not have to wrangle that tank out. I’ll take a closer look at it.
I would hook up a fuel pressure gauge before the fuel filter and go up the hill. You did say you replaced the fuel filter, right? Try unplugging you computer and using electrical contact spray, clean the electrical plugs going to it. This is not a catalytic converter issue, is it? You have good power at all times? Hopefully this is not a fuel pressure problem caused by the fuel pressure regulator . It is a big problem along with the spider injecton unit under the air plenum. The fuel pressure regulator is not that bad to replace. If you are losing manifold vacuum going uphill, it would directly affect the fuel pressure regulator.
Your vehicle has a Manifold Absolute Pressure sensor. This measures the barometric pressure relative to the intake manifold pressure. The signal from this sensor tells the computer when to advance the ignition timing and when to increase the fuel mixture. If you drive the vehicle where the barometric pressure decreases, such as in higher elevations, and this sensor is defective, you’ll get no power from the engine.
Tester
Changed the fuel filter. The fuel pump was replaced a couple years ago. Seem to run fine with power till going up steep hills especially in high altitude areas. It has throttle body injection. That’s a great point about the vacuum. Would the MAP sensor be a possibility. I’m assuming that it deals with air pressure?
Awesome. I was thinking that might be the culprit considering it mainly has the problem in high altitude. I’ve call an auto store and they sell one for $50. It would be nice to know for sure. I’m without a multimeter and specs. I’ll probably just replace it and see how it goes. Thanks so much!!
Also, don’t forget the Knock Sensor. It could be retarding your timing under a load uphill.BEFORE you buy that MAP sensor, Take off the vacuum line at the TBI going to it and run a coat hanger into the hole. They are famous for clogging up and not sending the right vacuum signal to the sensor. You might have to take the TBI unit off and clean the crud build-up at the vacuum passage-ways.If you do this, upon re-installation, hook up your fuel lines loosely first before you bolt the unit in its place.[Make sure the o-rings don’t fall off the fuel lines]
Some more great advice. I will do that. I didn’t think about a knock sensor. I’ll look for one. Does the MAP calculate barometric pressure through the vacuum port on the sensor, only?
Yes.
Whassup?
Before you get into the more complicated possibilities, check your air filter. It may be as simple as a dirty filter.