2.3L ('83-'97) 1987 Ranger Not Running

[Sailorlou]

Original engine. There are only two wires to each injector. Injector 1 and 4 have a red and tan wire. Injector 2 and 3 have a red wire and a white wire.

 

[Brain75]

the injector itself should have between 11 and 18 ohms resistance across the only 2 pins on the injector if it is stock and not some weirdo like the 3.0 flex fuel (which has bigger injectors, lower resistance)

that 11-18 spec comes from page 5-23 of the chiltons

 

[Brain75]

ah, so the red (hot) on all wires should have 12 volt from it to ground (positive lead of test to red wire, negative to ground) intermittently while cranking... with an analog test meter the needle will swing, with a digital test meter the pulses might be too short to even register or might lock up your meter. hence the noid light it will flicker where a DMM isn't fast enough to keep up.

 

[Brain75]

Electrically having 12v as you said you do in post #13 means the electical system is most likely correct

I don't remember off hand what a sticking shut injector will register for resistance, but electrically it is the same as a normally closed one, so I would think that a simple ohms test wont reveal if it is sticking shut.

here's the way to test a fuel injector is stuck - a bench test:

have a fire extinguisher on hand, and work carefully!

edit: grammar, incomplete thoughts.

 

[Sailorlou]

Thanks for the replies. I will pick up a NOID Light test set tomorrow.

 

[Brain75]

just a regular old 12 volt light, if you have a spare dash light, 2 small chunks of wire or alligator leads, some stuff laying around the shop you should be able to jury rig something to do the test... but again I think you are electrically fine. (if you do jury rig something up, just don't leave exposed segments that will spark, you are right there next to the fuel.)

I got to ask since you said it twice but wouldn't elaborate, 'oem spec' and 'new'... what BRAND are your new fuel injectors (the ones currently in the engine right?) are they motorcraft, bosch or something from autozone like carcraft, duralast, cardid, sorensen, etc?
Ford (motorcraft) used Bosch for fuel pumps and some injectors those things are great but you bleed for em, the rest of em are trash and should go back to the store if you have the receipt.

 

[Sailorlou]

Thanks. The ohmeric reading is on the money. I'll know if the injectors are getting the proper signals to open and close once I get the noid test light kit. It will be a good addition to my shop tools.

 

[Sailorlou]

The new injectors I have are motorcraft.

 

[scotts90ranger]

Even new injectors especially older ones can be stuck closed (they'll have the same resistance, the coil is stationary the pintle is what moves with the magnetic field), sometimes you can get them unstuck by tapping them with power and ground to a 9V or 12v battery. Fuel injectors in normal systems have constant power on one wire and a switched ground on the other wire.

A noid light is going to give you a much better idea if you are getting an injector pulse than a test light or volt meter, noid lights are faster response than most normal easy to find lights.

 

[Brain75]

I backed off on my insistence of testing the fuel injectors when he said they are motorcraft but glad to hear someone else say that new ones can be stuck closed... all I have messed with em is to go get junkyard ones (sticking to good motorcraft), and then wd40 em up to make sure they weren't sticking, bench test and go. Can't stomach the price of new ones.
I used to think buy every tool you need cause you will need it again, but later in life figured out the "I'll only ever need this once" stuff can stay on the shelf and I will engineer a tool good enough to get the job done...
I still think he is fine electrically without getting the noid light, but time will tell.... as long as he comes back and tells us what solved it in the end.

 

[Sailorlou]

OK. The Noid light did flash when turning the engine over. Found that the EEC Power Relay socket had some bad wires. Replaced the socket and relay. Now the engine will try to start and run for a few seconds, but won't keep running. Adjusted the timing and got it to run for a few longer seconds. Seems to be hitting on all cylinders but won't keep running. Unfortunately I have to leave on an extended trip so I won't be able to continue working on the truck until I get back and that won't be until next June. When I get back I will once again try to get it running.
Thanks for all your replies, some were very helpful. I will check back in when I return in June. Thanks again. Hope you all have a great holiday season.