2017 Hesitation issue at idle, replaced fuel pump and throttle body but still happening .

[Fasttimes]

My 2017 Limited for some time had been randomly dropping RPMs at idle. It'd be like when sitting at a light or coasting to a stop. The motor would drop to around 400rpm, then catch itself back up. This went on for some time till finally it didn't catch itself and the motor cut off mid-driving. Fun times.

Took to my local shop, scanned errors indicated bad fuel pump. They dropped the tank and replaced and put back together and the issue happened when they test drove. New error indicated throttle body bad. That was replaced as well and truck was picked up. I've been driving for a week now and it's not shutting down but I still get the rpm drop to 400 at stop. So far it's recovered, but I'm worried that something still not right.

Any thoughts or similar experiences? AI dive says Vacuum lines test or idle control valve. I guess I'll be taking it back, but it doesn't happen on command.

 

[AWAR]

Take it back for a followup. Might show something more in pending codes. Get the codes and we can see what it sees.

 

[99WhiteC5Coupe]

My 2017 Limited for some time had been randomly dropping RPMs at idle. It'd be like when sitting at a light or coasting to a stop. The motor would drop to around 400rpm, then catch itself back up. This went on for some time till finally it didn't catch itself and the motor cut off mid-driving. Fun times.

Took to my local shop, scanned errors indicated bad fuel pump. They dropped the tank and replaced and put back together and the issue happened when they test drove. New error indicated throttle body bad. That was replaced as well and truck was picked up. I've been driving for a week now and it's not shutting down but I still get the rpm drop to 400 at stop. So far it's recovered, but I'm worried that something still not right.

Any thoughts or similar experiences? AI dive says Vacuum lines test or idle control valve. I guess I'll be taking it back, but it doesn't happen on command.

If the shop replaced the fuel pump and throttle body assembly, and the problem still exists, they replaced items that were not defective (or installed a defective new part).

I’d return it to the shop.

 

[17expi]

If the shop replaced the fuel pump and throttle body assembly, and the problem still exists, they replaced items that were not defective (or installed a defective new part).

I’d return it to the shop.

They do it all the time. Good luck getting any money back.

 

[dkincaid32]

If it was me, i'd throw some new relays in and maybe look at the inertia switch in the rear. That is, assuming you or someone has already checked inside for vac leaks and whatnot.

 

[Fastcar]

Has anybody done a voltage check on it?

 

[rslynes]

Has anybody done a voltage check on it?

That would be my suggestion, too. Voltage/wiring/connection/battery issues toggle a myriad of faults and communications problems.

 

[Fasttimes]

Just picked up the truck, no issue found while they had it. They cleared all codes and said they drove it for a while and no issue appeared. I just picked it up a in 15 min back in my driveway the issue showed. Frustrated.

I mean surely that can't be normal to go down to 400 rpms and back up to the normal 600 right?

 

[Fastcar]

Just picked up the truck, no issue found while they had it. They cleared all codes and said they drove it for a while and no issue appeared. I just picked it up a in 15 min back in my driveway the issue showed. Frustrated.

I mean surely that can't be normal to go down to 400 rpms and back up to the normal 600 right?

Friggin' dealers! They cleared all codes?? WTF were the codes they cleared? That is probably where the info lies. What generated the codes? You could spend some money and buy a short money reader and keep it with you and hooked up. Pretty clear to me they can't diagnose shit. You might want to try timing the drop and how long it takes to recover, and, when you get the duration of it, how often does it occur.

 

[Fastcar]

Has the voltage at the injectors been checked? Might be an idea to take the injectors out and get them tested for flow. If you get a scanner/reader you'd be able to isolate each cyl and see if it shows the rpm drop your experiencing. I suppose you could do it by just unplugging injectors them one at a time as well. How many miles on it?