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Topic: Proper injectors for stock Speed Density 5.0 (Read 83 times) previous topic - next topic

Proper injectors for stock Speed Density 5.0

My car has been diagnosed as having a bad set of injectors, and it runs poorly. SOME of the injectors, at some pont in the cars life, have been replaced with ones that have a different housing.  I look at the parts store/rockauto, and there are numerous part #'s and slight variations in injector styles.  How am I to figure out what part # is correct for my motor?  From what I understand, injectors are very specific and it is crucial to the vehicle's performance that they be matched to the computer.
1988 Cougar LS

Enkei 92 Mesh wheels/BF Goodrich rubber - Upgraded front and rear swaybars - 7.5 Posi - Full sony sound system w/ dual 10" subs - Energy Suspension Polyurethane - Dual power seats - Custom fabricated front frame rails - AOD-E with standalone TCU

Re: Proper injectors for stock Speed Density 5.0

Reply #1
Assuming the diagnosis of bad injectors is correct, and the car you are referring to is the 1988 Cougar 5.0 in your sig, the stock injector is the old Bosch style EV1 14 lb/hr injector, usually gray in color at the top where it plugs in. I don't have the original part #, but its probably obsolete/discontinued anyhow. This link to equivalent replacements for sale at Amazon may have some additional part # info or reference:

https://www.amazon.com/MOSTPLUS-14LB-Injectors-F47E-A2E-0280150710/dp/B07PMVV9JM/ref=sr_1_2?dchild=1&keywords=14+lb+injectors+ford&qid=1596404733&s=automotive&sr=1-2

Not to undermine whoever diagnosed the bad injectors, but I'd also have them check all engine vacuum lines, especially ones under the upper intake plenum going to the fuel vapor charcoal cannister, the map sensor, the pcv valve, etc. The speed density system is sensitive to vacuum leaks, and the rubber lines under the upper plenum are highly prone to aging cracks/leaks, which will cause extremely poor driveability/idle.

An HO conversion might be an option too, Cool Cats website has a write up on whats involved with that if you are interested.

Re: Proper injectors for stock Speed Density 5.0

Reply #2
Yes, I plan to do an entire GT-40 intake swap in the near future, and talk to BBK about a setup for uprated injectors, MAF, fuel rails, etc, and a mass air conversion.  But since, with my current list of projects, that may be a little while longer than anticipated, i just want to get it to run properly as is for the time being.  I'll check the vacuum lines as well for damages.
1988 Cougar LS

Enkei 92 Mesh wheels/BF Goodrich rubber - Upgraded front and rear swaybars - 7.5 Posi - Full sony sound system w/ dual 10" subs - Energy Suspension Polyurethane - Dual power seats - Custom fabricated front frame rails - AOD-E with standalone TCU

Re: Proper injectors for stock Speed Density 5.0

Reply #3
https://www.rockauto.com/en/catalog/mercury,1988,cougar,5.0l+302cid+v8,1198605,fuel+&+air,fuel+injector,6224

so all these injectors, with a whole list of compatable part numbers on some, all seem to have the same body style.  I would be inclined to believe that they are all the same, just from different manufacturers, but i notice that several are from the same company, but with different part numbers themselves.  Also, the ones listed on the site seem to be from an 'E' series of part numbers, while the one you showed me covers an 'F' series.  Am I overthinking this?  or are there valid small differences?
1988 Cougar LS

Enkei 92 Mesh wheels/BF Goodrich rubber - Upgraded front and rear swaybars - 7.5 Posi - Full sony sound system w/ dual 10" subs - Energy Suspension Polyurethane - Dual power seats - Custom fabricated front frame rails - AOD-E with standalone TCU

Re: Proper injectors for stock Speed Density 5.0

Reply #4
14lb EV1 style injectors are stock on a 86-88 5.0 Thunderbird/Cougar. Don't even worry about larger injectors till you have a HO cam and MAF.
88 Thunderbird LX: 306, Edelbrock Performer heads, Comp 266HR cam, Edelbrock Performer RPM intake, bunch of other stuff.

Re: Proper injectors for stock Speed Density 5.0

Reply #5
https://www.rockauto.com/en/catalog/mercury,1988,cougar,5.0l+302cid+v8,1198605,fuel+&+air,fuel+injector,6224

so all these injectors, with a whole list of compatable part numbers on some, all seem to have the same body style.  I would be inclined to believe that they are all the same, just from different manufacturers, but i notice that several are from the same company, but with different part numbers themselves.  Also, the ones listed on the site seem to be from an 'E' series of part numbers, while the one you showed me covers an 'F' series.  Am I overthinking this?  or are there valid small differences?

Not really, the differences in part # or application probably stems from the fact that Ford used your 5.0 fuel injected standard output, or SO, engine in multiple vehicles over the years throughout the 80's and 90's.  Everything from Lincoln Town Cars to lowly E150 work vans. Same fuel injector, same basic fuel system in operation, just packaged slightly differently since a van has a different engine bay than a Crown Vic.

The important thing would be to ensure that you get ones rated at the 14 lb/hr rating because your engine computer is using that assumed fuel flow rating across the injector. Make sure any injectors you get have new  O-rings and lube them while installing, engine fires are no bueno.