Gas Hog After Intake Manifold Replacement

V

velociamator

New Member

Nov 18, 2011

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Northeast USA

Sep 14, 2015

#1

• Sep 14, 2015

• #1

2004 GT 4.6L,stock except for a 3.73 axle. The large "Nipple" on the right side of the intake at the firewall broke and was spewing coolant.I replaced the "underneath" heater tube and its O-ring part behind the water pump, the water pump itself, 8 spark plugs,both heater hoses,and the manifold from Ford Racing. I just cleaned the fuel injectors externally. All anti-seize,sleeve retainer,Silicone dielectric,etc.,were utilized correctly,& everything gapped,cleaned,and adjusted appropriately. So now I've gone from 19.5 mpg to 8.5mpg in 95 miles.No fuel odor. The engine runs somewhat erratically,with a "pop pop pop" idle. I have to either get an OBD-II device or pay the man to check codes,or get a new set of injectors--or who knows what. Any thoughts on this?

 

BrothersPerformance

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Sep 1, 2009

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3060 Performance Circle, Deland, FL, 32724

Sep 15, 2015

#2

• Sep 15, 2015

• #2

You are dumping a lot of fuel. Your local auto parts store should be able to check the engine codes for free.

How did you clean the injectors?
Double check all your hose and electrical connections.

 

wmburns

SN Certified Technician

Aug 14, 2009

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Sep 15, 2015

#3

• Sep 15, 2015

• #3

It would really help if you posted the full ODB2 DTC codes. There are 1000's and they each have a story to tell. No excuse as almost all auto parts stores will read the DTC codes for free.

Has the fuel rail pressure sensor (FRPS) vacuum intake reference line been connected and is it leak free? If this line is missing, this would case the fuel mixture to be very rich at idle and part throttle.

+1 on the possibility that the injectors were damaged during cleaning. Consider an injector cleaning/flow test service such as InjectorRX.com.

Have you made any other "mods"?

Check the oil for gas. Don't drive this car if there is large amounts of gas in the oil.

Has the alternator been tested for excessive AC ripple (bad diode)? A bad alternator can "cause" other symptoms that don't appear to be related.

 

Last edited: Sep 16, 2015

V

velociamator

New Member

Nov 18, 2011

23

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Northeast USA

Sep 15, 2015

#4

• Sep 15, 2015

• #4

Aaaarggh! I thought I had this figured out. I "noided" #6 cylinder jack after disconnecting #6 injector,and as a result,replaced #6 injector (Engine no different w/#6 plugged in or not). Then it ran the same, and the "Check Engine" light came on, so I dropped it off w/the techs who will tell me what it is tomorrow am.

 

BrothersPerformance

Premium Sponsor

Sep 1, 2009

261

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3060 Performance Circle, Deland, FL, 32724

Sep 16, 2015

#5

• Sep 16, 2015

• #5

Good luck!

Let us know how it goes.

 

mogs01gt

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Jul 22, 2002

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Sep 16, 2015

#6

• Sep 16, 2015

• #6

velociamator said:

Aaaarggh! I thought I had this figured out. I "noided" #6 cylinder jack after disconnecting #6 injector,and as a result,replaced #6 injector (Engine no different w/#6 plugged in or not). Then it ran the same, and the "Check Engine" light came on, so I dropped it off w/the techs who will tell me what it is tomorrow am.

Click to expand...

Honestly, it sounds like something is hooked up wrong.

 

V

velociamator

New Member

Nov 18, 2011

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Northeast USA

Sep 17, 2015

#7

• Sep 17, 2015

• #7

It was this expensive electric PCV valve on the right side valve cover under the air intake (showed up as a vacuum leak),and #6 needed a coil,NOT an injector. I get to keep the injector as a reminder not to blunder blindly ahead on guesses. More than $400.00, and when test driving it,they found it needs lower control arm bushings--right side is trashed. I know I could get aftermarket arms,but I haven't seen the bushing kit by itself online. Anyway, the engine is running as it should,and my "shade tree" intake manifold/heater tube/water pump/heater hoses/spark plugs job is vindicated. The other thing that happened was that as soon as I was ready to start it at the time the manifold job was finished,the battery ended its life. So,$150 at the Ford dealer,about $900 for parts,tools and supplies,I am just under $1500.00 for September (not including the rear suspension work coming up). If I hadn't done the manifold etc. myself,that job would have been at least another $1100.00.

 

BrothersPerformance

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Sep 1, 2009

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3060 Performance Circle, Deland, FL, 32724

Sep 17, 2015

#8

• Sep 17, 2015

• #8

I'm glad everything is resolved!

 

Noobz347

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Sep 17, 2015

#9

• Sep 17, 2015

• #9

velociamator said:

I know I could get aftermarket arms,but I haven't seen the bushing kit by itself online.

Click to expand...

Control Arm Bushings
MM also sells, "The Tool".

 

V

velociamator

New Member

Nov 18, 2011

23

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Northeast USA

Sep 23, 2015

#10

• Sep 23, 2015

• #10

Well,I did finally get it back,went right up and had the Ford dealer check the rear suspension and do a LOF. The parts are obsolete,but they could get them NOS from other Ford dealers. Hardly worth it,as Summit Racing has a kit for both upper and lower arms. The trick is to press out the lower arm bushings. The lower right is all that's shot, but why not build something better? And thanks much for the link! I shall look into that as well. The intake manifold/heater tube/hoses/water pump/spark plugs/injector work I did turned out well, and the engine is mad powerful now,but no hole shots/burnouts 'til I get the ass end fixed. Thanx to all.