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How to test if injectors and sensors work

Posted: Thu Dec 22, 2011 10:04 pm
by david martin
I purchased a Ford 5.0 port injection intake manifold with injectors, fuel rails and throttle body. I'm unsure if the injectors, TPS and IAC Sensors work.

The injectors I believe are motorcraft brand model number E5TE-A3B. Is there a way to check operation other than installing and plugging them in? On a couple of the injectors, the plastic cup at the tip is cracked. Can this part be replaced or will I need to replace the entire injector? How about the rubber O rings at each end? Lastly are the female connector plugs available or will I need to buy a wiring harness on ebay and cut them off?

Is there a way to check the TPS and IAC on the bench?

Thanks

Re: How to test if injectors and sensors work

Posted: Fri Dec 23, 2011 12:55 am
by trakkies
Measure the resistance of the injectors. They should all be approx. the same. In the UK Burlen Fuel systems sell spares (like the pintel cap) for some Bosch injectors, so I'd guess others do too. The plug appears to be a Junior Timer type so again easily available here.
Both IAT and CTS normally vary their resistance with temperature so can be checked with a DVM. The manual gives details of the common ones' resistance at various tempertures.

The TPS is usually just a potentiometer. Same as a volume control on an amplifier. if you apply volts to the track - no more than 5, from say a small battery - the output should vary smoothly from min to max as you turn it.

If you can find a complete used engine loom from a car fitted with your manifold, that can provide an economical basis for your MS loom. Find the car wiring diagram, and note the wiring colours the maker uses, and cross reference to the MS one. If the loom is long enough you should be able to wire most of it direct to either the MS DB37 or relay board avoiding extra connections where not needed.
It is good practice to draw out the wiring diagram for your individual installation showing the wiring colours you've actually used anyway - will make any fault finding at a later date so much easier.

Re: How to test if injectors and sensors work

Posted: Sat Dec 24, 2011 8:45 am
by david martin
Thank you Dave! I still have alot to learn, but you saved me alot of time by pointing me in the right direction.

Have a wonderful Christmas.

Re: How to test if injectors and sensors work

Posted: Mon Jan 02, 2012 4:58 am
by convertables_10
Hey Dave I have a text file is done that way. Most of my factory harness was coded according to the megamanual colors. It has been one of my best diagnostic i have. Im building a new harness for my tpi project.

Re: How to test if injectors and sensors work

Posted: Thu Jan 26, 2012 7:49 am
by trakkies
Sadly the MS colours bear no relation to the BS ones my UK car uses - so to avoid confusion I used BS ones. The BS colour for 12 volt positive unfused is brown - yet Europe uses brown as ground. So it's as well to stick to just the one system. :D