Are the injectors n fuelpump connected n ecu

[frankensvo]

Im stumped...FRANKENSTANG was runn great...dropped it off stands to go get xhaust hangers welded on...no start...found the problem by wiggling harness it was a loose splice...fired it up n ran ....shut it down n taped wires up again ...tried to start....nothing ?...coil is firing but fuel pump and injectors are not?...I have main power to fuel pump relay and to the energizing circuit has a slight glo on circuit tester with key off and it gets way brighter when key is on?...I took the relay off n activated it with a batt charger and it is clickin. Put it back in circuit but nothing when I hit the key?...Fuel pump runs when I jump circuit with batt charger but but car won't start?...ECU fried ...Thanx n advance for input...🧐....

[Stinger]

I'd start by doubling checking that the connection you wiggled to "fix" it the first time is actually getting a proper connection after taping (taping is not a good way to fix loose connections).

[frankensvo]

I used the solder shrink sleeve method...has a band of lo temp solder inside a sleeve of hi temp plastic sleeve...the band actually shrinks then melts locking the strands together. I use the tape to bind the group together then plastic conduit scavenged from the junkyard with electricians tape barber poled around it...It was runnin GREAT too until this happened. I got your 3" pass pipes on n held n place "sounds SWEET!" and took it off the stands to take it to get the hangers tacked on....Is there suppose to be lo volt amp current going thru the system until you turn the key on ?...I use a test light at the fuel pump connection on the activation circuit after relay, on the relay activation circuit and on the test vip on the fuel circuit lead and all have DIM light until I turn on the key then its BRIGHT. I have a bright white spark from the coli when I crank it also....I used the batt charger at the pump feed wire in the relay n relay clicks. I spliced into the pump power feed wire and pump works. I Then I hit the key n cranked it figuring it would fire but didnt fire so this tells me the injectors are not opening either?...Are the injectors and fuel pump using the same input output in the ecu ?...I thought spark n injectors were on the same circuit ? I know its all part of working on these machines till things are figured out but to have it runn n runn GREAT  then to take it off the stands n nothing just makes me go ....UGH ..lol...I've gotten mellower in my old age n think...BE GLAD IT HAPPENED IN MY GARAGE n NOT GOING TO EAT LASAGNA 30 miles away on a sunday afternoon !

[frankensvo]

I went out n checked the injector circuit and it is doing the same thing as the fuel relay n vip connector lo volts "dim test lite" with key off n high volts "brite lite" with key on...I looked up the schematics n found that the fuel pump relay and the injectors both share pin 22 in the ecu....and injectors also use 58 n 59....I'd post a pic but there is no option that I can see on this page ? Is the circuit suppose to have a lo volt current going to it with the key off

[Stinger]

Off is off, on is voltage.

I'd see if the code scanning function works. This is a good indicator of ECU function.

[frankensvo]

I went to trouble codes.net to get instructions as I don't have a code reader. I hooked it up as described in their display and no check engine light comes on or flashes. I have the merkurXR4Ti s.a hareness on my 93 mustang so I don't think the ecu can communicate with the check engine light ...Unless the ecu is fried or I'll have to get a OBD1 scanner

[Stinger]

I don't know if your check engine light is hooked to anything or not so I can't help there. An EEC-IV code reader is under $30.

[frankensvo]

Aug 17, 2022 20:25:35 GMT -5 Stinger said:

I don't know if your check engine light is hooked to anything or not so I can't help there. An EEC-IV code reader is under $30.

Yeppers I've got one on the way...also been sourcing LA3's and LA2's...is there a diff in the 2 other than the year made ?...

[xr2300]

The LA2 and LA3 are essentially the same.

[Stinger]

Correct

[frankensvo]

UPDATE found the problem...not on my own tho but with a member of SVO Mustang ownwers/fans CLIFTON BJORKLAND who nudged me toward ground issue...he even sent a pic of the connector to check "MAIN GROUND FOR ECU". Pushed it together n BAM it started

[Stinger]

Good to hear!