Engine Running Poorly

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Mar 3, 2006 | 02:32 PM

todd88

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Joined: Oct 2005

Posts: 97

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From: Jacobus,PA

Engine Running Poorly

Ok here we go, my truck started running really poorly sputtering and no real throttle response. I can run and drive it ,it just feels like there's no throttle or umf!
I was messing around in the engine bay looking for a leak ,wiggling hoses etc. I accidently wiggled to hard and the vac line to the fuel pressure regulator broke allowing air in to the intake the engine started to run better???? So I rigged it up and it started to sputter again. Here's the catch I thought well I 'll take-off one of the capped off vac lines on the tree and the same scenario it started to run better??? I need help -is the EGR bad ? or something else that I'm not considering. It's like the intake isn't getting enough air??? Air filter is new.
Need help from anyone who can add some insight ;from past experience ,before I start throwing parts at it. It's a n 88 F-150 4.9L EFI 4wd 5spd- 159K on the clock. Appreciate any assistance. I'm going to post on the Inline 6 section as well ,I thought this is a general problem so I'd try here too.

Mar 3, 2006 | 06:44 PM

SUPER6

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Joined: Feb 2006

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Could Be A Mass Air Flow Sensor.

Mar 3, 2006 | 09:40 PM

Fully_Loaded

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Joined: Oct 2003

Posts: 986

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From: Gulf Shores, AL

Quote:

Originally Posted by SUPER6

Could Be A Mass Air Flow Sensor.

This truck does not have a mass air flow sensor.

Sounds like an air problem. When you disconnect one of the vacume lines it allows a little more air into the intake. I had a similar problem and it was a clogged air filter, check it out and keep us posted.

Mar 3, 2006 | 11:35 PM

Dr.Reese

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Joined: Feb 2006

Posts: 115

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From: Tn.

thought for the day

a bad EGR would make your engin rpm loop does it do anything the higher your rpm's are i say that because your EGR is not used at WOT (wide open throttle) you can get a EGR Gasket for 3 bucks and takeoff your EGR flood it with brake part cleaner let it soak for 20-30 min.then dump it out on a shop rag and it is best if you can blow it out w/ an air compressor repeat a few times to get all the carbon and crap out of there FYI EGR's most oftenget clogged and stuck due to faulty cats. also cloged idle air control valve can cause it to run like crap you can take it off hose it down with brake part cleaner and reinstal the gasket is reuseable; have you checked your ignition system i know it sound so simple but just 1 burnt plug wire arcing on the manifold will cause the same side effects and finaly the last thing i can think of is a secondary ground from intake to firewall you are looking for a silver braded flat wire if this ground is poor or faulty it will cause the ECU to go nuts O 1 more it could be your ECU end of story but ya can't realy check the computer so only as a last resort because if you even open the box that it comes in you can not return it no way no how well unless ya find an exact match at a salvage yard "almost never gonna happen"