07 ram rpm question

[1badman]

07 1500 5.7 hemi. while coming to a stop I feel and see the ROMs drop a few hundred and quickly go up to normal around 500. no engine light on. is this normal or know problem. where should I start. thanks.

 

[MegaMouseGW]

If you have an automatic this is perfectly normal. A stick will do it sometimes also but not as bad. It is the engine management system purging extra fuel out of the engine. Also until the convertor in an automatic decouples it will cause a drop from normal idle.

 

[Gecko]

If you have an automatic this is perfectly normal. A stick will do it sometimes also but not as bad. It is the engine management system purging extra fuel out of the engine.

Would this mean your running to rich? Or is there too much volume of fuel in the system? And if thats the case would it be the fuel pumps fualt and a good idea to replace it? I'm having a similar case.

 

[MegaMouseGW]

Would this mean your running to rich? Or is there too much volume of fuel in the system? And if thats the case would it be the fuel pumps fualt and a good idea to replace it? I'm having a similar case.

The engine is not running rich it is something that is normal. All the fuel pump does is to pressurize the fuel rails and provide the injectors with the fuel. This has more to do with the actual injectors loading up on fuel during normal operations, then when you let off the gas they can have a bit too much gas in them and they purge it by dumping it into the cylinder until the next cycle.
Diesels will do this more often and when they do they put out a lot of white to black smoke out the exhaust (normally black), Cats are more prone to loading up but cummings and other diesels can do it also under major loads.

If you want to lessen the problem (which it is not really one unless codes are getting thrown), you can invest in a good tuner and set it for economy which can give you better mpg, and lessen the drop in rpm's.
Like I said though with an automatic tranny the convertor does not uncouple totally and is the normal cause of the drop in rpm's and in that case there is not much you can do about it.

 

[Redtruck-VA]

Welcome to the forum, I would check the trans fluid level and clean the TB.

 

[Gecko]

Welcome to the forum, I would check the trans fluid level and clean the TB.

Actually this could be my issue. I believe I'm due for a trans flush and a diff fluid change as well. Maybe I'll just have to order my TC and VB sooner and do it all at once

 

[Sparkyy]

07 1500 5.7 hemi. while coming to a stop I feel and see the ROMs drop a few hundred and quickly go up to normal around 500. no engine light on. is this normal or know problem. where should I start. thanks.

Welcome to RF! You should introduce yourself over here but often wonder that myself. Now I know thanks to you.

Actually this could be my issue. I believe I'm due for a trans flush and a diff fluid change as well. Maybe I'll just have to order my TC and VB sooner and do it all at once

How many miles you got on the truck?

 

[Gecko]

145k. I've done it before but I believe it was around say 100k-110k miles. I don't remember I have to check.

 

[Sparkyy]

Ahh not to bad for usage but getting close.

Was wanting to do a full drain on my tranny but could never get the damn fitting to loosen for me.

Draining using the pump to just clean out the system and then pour all new fluid in but at 70k miles. The truck is running great so I'm just going to drop it at 90k and swap 7-8 qts out again.