nofords

iTrader: (9)

I have a complete engine drop out of an '87 N/A A/T car that I have swapped into my 88 N/A M/T car. The "new" engine was taken out without removal of the harness off the engine. Not wanting to disrupt the intake to remove the secondary injector sockets, I chose to sever both harnesses on the engine side (between the MAP and primary injectors) and amalgamate to two.

Now, neither harness will not mate as the wiring is different. Neither harness fully matches the FSM. yeah, it was a dumb idea but now i have to fix it!!

Does anyone have an itemized list of the the 31 wires that go to the engine?

On the 88, I have four black with yellow stripes that I cant find on any of my schematics and the same goes for the 87 which has several striped tan wires unaccounted for.

I've been looking at schematics for the last 4hrs and my eyes are not happy!!

Thanks in advance!

HAILERS

Too hard to fix. There are a number of wires that are spliced together inside the harness. Like all the brown/white wires at each sensor are spliced together inside the harness and terminate at pin 2A of the ECU as one wire.

Same can be said of the ground wire at each sensor. On a early series four they are colored brown/black at each sensor and are all spliced together inside the harness and arrive at the ECU as one wire. Later cars use a pure black wire as gnd at each sensor but do the same as just described......come to the ECU as one wire at pin ??? 2C.

Early series four that had the solenoid resistor package, will have two black/yellow fuel injector wires coming out of X-15 and then get spliced together shortly after and go to the solenoid resistors round plug. But on later cars with no solenoid resistor package, there will be four black/yellow wires going from X-15 directly to the fuel injector plugs.

By the way, the secondary fuel injector plugs are easily accessible because they are right out in the open on the right side of the engine. The primarys are under the intake manifold.

What it sounds like to me, is you have a harness meant for high resistance fuel injectors (88) and a harness for low resistance injectors (87). If your putting in a 88 engine in the 87 body, then just use the 88 EM harness even if you have to pull the upper Dynamic chamber off. Takes but twenty minutes to do so. Then resplice that harness back together.

Online manuals only show the later cars with high resistance fuel injectors. The early 87 and 86 are shown in the attached jpg.

HAILERS

Sorry, the site or moderator won't let me post the jpg of the early 87 cars. I've posted that jpg recently on other threads.

Anyway, go to this therad: https://www.rx7club.com/2nd-generation-specific-1986-1992-17/power-injector-problem-s4-tii-838464/ and I posted a jpg of the fuel injectors on a early car there in the second post. Then compare that dwg with the ones you have and you'll see the difference b/t the early 87 and the later cars i.e. no fuel injector resistor package hence four black/yellow on the newer cars. X-15 is called FEM-01 on the newer cars dwg's.

I click on MANAGE ATTACHEMENTS and nothing happens til the SOMETHING times out and then I can at least leave the site or go on to another post. Same thing with going to the thread sited just above. Click on the jpg and nothing happenss until SOMETHING times out so I can leave the post/thread and go on to something useful.

DrKillJoY

PM me with the error you are getting when trying to attach a jpg. Thanks.

arghx

iTrader: (3)

If you value your sanity, post a "want to buy" ad in the for sale section for an 88 nonturbo manual harness. Then replace everything. Use it as an opportunity to redo the vacuum lines and such, which will have to be done anyway.

nofords

iTrader: (9)

I looked at that link and the photo at the bottom is an appendage I have on the 87 harness. So, I guess your right! Cool finally something that makes sense.

Now, would it be wiser to reassemble the 88 harness, replace the 87 injectors with the 88 ones and use the 88 ECU or reassemble the 87 harness and use the 87 ECU?

As far as replacing the vacuum lines, the engine is a recent rebuild that runs well (well, at least it did!!) so, the lines actually look decent.

RotaryRocket88

iTrader: (7)

Does the '87 harness have a resistor pack and low imp injectors (offset tab)? If not, then the injector wiring will be the same on both the '87 & '88 harnesses, and both will require high impedence injectors (centered tab, red).

nofords

iTrader: (9)

both sets of injectors have center tab and red. However, there is a resistor pack on the 87 harness.

In any case, I soldered the 88 harness back together and swapped the injectors and the car runs. I am just having an issue with it running well now.

Just starts and dies. I'm too irritated and tired to work on it! I fear that the seal on the upper intake is not as good as it needs to be.

HAILERS

Two things you might look at. Get a meter out and go to the ECU. See if the ECU is seeing the afm signal. Compare your readings with the key ON to the FUEL AND EMISSIONS seciton of the FSM. In specific the pages called CONTROL UNIT.

Also take a look at the water thermo sensor signal at the ECU. It should read 2-3 vdc if the engine is cold. The value will drop down to a half volt when the engine gets hot. If you don't see 2-3vdc, then see if the plug is on the water thermo sensor or not. We know you have the elect plug on the AFM. Right? Right

Also the engine will be difficult to start if the water thermo sensor signal isn't there. The ECU uses it for the internal Start map inside the ECU. I'd post a jpg but there's still something that keeps me from posting jpgs.

HAILERS

.

nofords

iTrader: (9)

Well...the engine ran right away when i did the swap and progressed to running then dying and now won't even sputter now. I'm going to try the metering tomorrow. See what I get!

Thanks for the help!! I'll post my readings.