odd stumble when accelerating

[OR VietVet]

What hapened with doing the TPS and fuel pressure check?

 

[RLC2020]

What hapened with doing the TPS and fuel pressure check?

I haven't done either of those yet. I need to acquire the equipment to do so. Been pretty busy lately and haven't had time to mess with it just yet.

I just reread the thread and saw that the OBDlinkMX was recommended so I ordered one off amazon, should be here tomorrow. Once that arrives I'll check the tps and post the results here.

 

[OR VietVet]

Ok, I just asked because I don't want you to just throw money at it till some diagnostics are done and having that OBDlinkMX will be there for the future.

 

[Doubeleive]

I'll try tow mode and see if that makes a difference. I disconnected the battery the other day to "reset" things. Seems to have made it worse. It was actually shifting bad in all gears for the first few miles I drove it after that. Now it's back to just doing the 2nd gear stumble, but it's worse. I almost got rear ended the other day, it stumbled and I had to floor it to get it to accelerate while merging. Really not sure if this is a trans issue or a tune up issue, but the engine seems to run fine everywhere else. I have 55k on it and no record that the trans fluid was ever changed. I'm contemplating doing a fluid / filter swap first to see if that makes any difference. I'm nervous to "tune" anything right now because if I have a real issue going on I don't want to cover it up or make it worse. I'm kinda lost right now as to what to do first. I'll try to get a good video of it asap

you could try just running around town in 3rd gear and watch the rpm gauge see if it bounces around when it stumbles in 2nd, you won't hurt anything doing this, it just rev's the rpm's up higher, that might give you a better idea of where the problem is.

 

[Fless]

I haven't done either of those yet. I need to acquire the equipment to do so. Been pretty busy lately and haven't had time to mess with it just yet.

I just reread the thread and saw that the OBDlinkMX was recommended so I ordered one off amazon, should be here tomorrow. Once that arrives I'll check the tps and post the results here.

Not sure of the difference but I noted the MX"+" model.

 

[RLC2020]

Not sure of the difference but I noted the MX"+" model.

I just double checked. I ordered the "+" model.
Once it arrives I'll be downloading the app and checking things out.

Also: This morning I drove the truck in Tow/Haul mode and it drove 100% perfect. Still not sure if it's the trans is upshifting too quickly and the engine falls out of the power band, or the engine is not running right which causes the issue. Either way, tow mode kept the rpms up and when it shifted into 2nd it kept pulling like normal. I'm thinking once I get the tps data and fuel pressure numbers, if everything looks good there then I'll just go ahead and get a tune for this thing.

 

[RLC2020]

So, to update this thread, i think the issue has been resolved. Believe it or not, I used some snake oil and I'm pretty sure the issue is gone. I dumped a bottle of the Royal Purple Max Clean fuel system cleaner in and I'm about halfway through the tank and it's running 100% smoothly at this point, even my rough idle has cleared up. I've been driving it pretty hard, lots of WOT pulls and drove in tow / haul mode to keep the rpms up for the first 3 days. I think this thing was driven by a grandma before me and the injectors were dirty. I'll update again if the issue returns, but it seems like it's good to go as of now.

 

[OR VietVet]

I recommend that if you have been running 87 fuel, that you run 89 or higher fuel for the better fuel system cleaning that they offer.

I run 89 for a tank full and then when down to 1/2 tank I fill with 91/93 and then at next 1/2 tank I go back to 89 and so on and so on...

 

[02Lightning]

I recommend that if you have been running 87 fuel, that you run 89 or higher fuel for the better fuel system cleaning that they offer.

I run 89 for a tank full and then when down to 1/2 tank I fill with 91/93 and then at next 1/2 tank I go back to 89 and so on and so on...

That's a new one for me, "higher octane fuel contains better fuel system cleaning". As far as I knew, higher octane fuel just allows slower combustion so you can run more timing. Then if the vehicle is not tuned for it, the higher octane will leave more deposits in the combustion chamber.

 

[OR VietVet]

Yes, that is correct but the higher priced fuels also have more additives, at least at Chevron they do, that help keep fuel systems clean. You can always get fuel system cleansing additives and add it to the regular tank of gas that you may use.