Texas_Ace

iTrader: (18)

It is spliced into the Brown with White stripe wire, no idea what it is, i think the black one is ground so not sure what this is or what that wire went to.

And yyeah kinda, it can sorta get past 3800, instead of it acting like a rev limiter at 3800, it hits 3800 and then the motor starts sounding differnt all of the sudden, has no power and will slowly keep revving a little higher but it is totally differnt then what it was. The secondary injectors are at least firing now i know that from the way it is acting.

I might have found some injectors locally, if so i will grab them and see what happens in a few days. If not then i might swap injectors on my car and go from there.

Either the injectors are not working right now or the ECU is not telling them the right thing.

Also gonna try running some injector cleaner through the gas and see what i can come up with doing that.

ItsFun

iTrader: (25)

How doo you know the wire you grounded was actually a ground? Use a DVM? Have you pulled voltage from your boost sensor and checked if its in spec? Have the orfice in the boost sensor line?

satch

iTrader: (1)

Definitely check for the restrictor pill in the vacuum line that connects to the boost sensor.

Texas_Ace

iTrader: (18)

As i said, i don't have a clue what that wire is, just saw that wire laying in the fender well and figured i might as well try grounding it and see what happens. I actually doubt it is a ground after looking at it.

No, i do not have a pill in the vacume line, was not aware you needed one, don't think my old car had one either.

Would the boost sensor cause problems only above 3800? below that it runs great other then the random timing changes, it is only above 3800 that i have issues.

Nope, not there, is it really needed on an NA? what will it effect?

satch

iTrader: (1)

On my car,early 86, installing the additional ground worked wonders for it "used" to stumble at 3800 rpm and although it stumbled it was able to make it through onto higher rpms but it didn't get there w/o a severe lag and now it doesn't. The thing is my 86 boost sensor wires do not match up with the 88 wiring diagram online. Could you give us the color of the 4 wires that are connected to your boost sensor? The 88 wiring diagram depicts only two wires that connects to the boost sensor and the AFM as well. Of these two wires one is black and the other is brown/white but the Br/W wire carries voltage so that couldn't be the correct wire according to the 88 wiring diagram, while B is a ground wire according to the 88 wiring diagram.

Texas_Ace

iTrader: (18)

Well my car was made in 01/87 so not sure if it needs that ground or not.

I can get the wire colors tomorrow when it is light again, too dark now.

I have felt a hesitation at 3800 before, this is not that. Once it hits 3800 it just starts running like junk no matter how high you rev it.

There is a very small possiblity that i am so low on gas that is causing issues but i would think i would have issues all the time. Still gonna try dumping every injector cleaner i can find in the tank and filling it up tomorrow along with changing the fuel filter should eliminate any issues with the fuel system.

This has really got me stumped, not sure what the problem is, i have a feeling it is somthing real simple, things like this usually are.

On another note i also get this REALLY annoying BEEEEEEP anytime the key is on, not the rev limit/water low buzzer but a beep. No lights, codes or anything else i can figure out that would cause it, so not sure what it is.

satch

iTrader: (1)

If the beep is constant or occurs when driving on a bumpy road then it is the ignition cylinder showing its age. The easy tell would be to jiggle the key a bit when the beeping ensues and if that stops it you need to lighten the load of the keychain.

ItsFun

iTrader: (25)

Have you simulated load whhile in your drriveway yet. To me it still sounds like secondaries not coming online at all. If you simulate load and get an assisant you can check voltage for the injectors at the engine. The primarys at 3800 are suppose to cut to half load while the secondaires come online I believe. If you have not voltage change at WOT then they arnt coming online I believe. Again, secondaries don't come online unless a load is simulated.. And always have 12v ( or battery volts) with the key on or car running.

satch

iTrader: (1)

One thing I forgot to mention and that is if you pull the vacuum line off the car, check to see that you have vacuum with the car running for you should. Also, try plugging the end of the vacuum hose from the boost sensor after you verified it has vacuum and then with the hose plugged check to see how the engine runs at higher rpms. Your vacuum hose should have the restrictor pill in it so get one and they are cheap. Lastly, the Factory service bulletin would apply to your car and the ground wire is either black or brown/black and not brown/white.

Texas_Ace

iTrader: (18)

The beep happens anytime the key is turned on, i have not found a way to make it stop no matter what. if the key is on it beeps. Just the key for the car so no weight on it, the cyclinder IS worn though, i grapped the key to my other RX7 and it started this car fine, didn't even notice till later i got the wrong one.

How do you simulate load?

When i was hitting a wall like a rev limiter they were not coming on at all, i know this because on one of my old cars i had to drive it for a little while with the secondaries not hooked up at all and it did exactly the same thing.

Now that it is just running like junk over 3800 i think they are coming online but not working right.

I checked the voltage on the secondaries, when it would not go past 3800 at all it was constant, now they are firing just not right i guess.

Gonna do more testing tomorrow, checking the primaires is a good idea.

Yes, the car pulls good vacume.

With the boost sensor line disconnected it runs about the same as it does with it connected, at least the last time i tried that, still would not passs 3800. I will try it again tomorrow now that it is going past 3800.

So i should reground the boost sensor? when was the cutoff for that? I thought they stopped that in mid 86? mine was made in 87. I could very well be wrong. There is a black wire, i will try grounding that and see what it does. Can't figre out why the PO had this wire spliced into it though.

satch

iTrader: (1)

A plausible answer is it could have been a booboo!

Texas_Ace

iTrader: (18)

It is possible, just kind of a strange boo boo to make

ItsFun

iTrader: (25)

To simulate load warm up car, unplug boost sensor vacuum and plug hose. Unplug tps. Rev past 4k. Load simulated. Make sure car is warm.

Texas_Ace

iTrader: (18)

Well if this rain lets up i will try that and see what happens.

satch

iTrader: (1)

It's a safe bet that the previous owner tried to add an additional ground and chose the wrong wire. With the key to on check for voltage on that wire. Chances are it will have voltage close to 5 volts or so. If it has "any" voltage then it is the wrong wire to ground, guaranteed.

On an additional note, the restrictor pill prevents the ECU from being confused and the car could buck w/o it. I believe the part # is "8931-13-986"

Texas_Ace

iTrader: (18)

Well i will pick up a pill.

So did a little testing today, only was able to do a little due to the rain. Basically tried differnt combos of unplugging the TPS and pressure sensor, no matter what i do it still has no power over 3800. It revs and drives perfect under 3800, over that it drives fine IF i only give it light gas. But if i go WOT it suddenly loses all power and falls on it's face and starts dropping back down to 3800. Doesn't matter if i am at 4k or 7k.

the sound of the engine totally changes when i go from part throttle to WOT and it loses power as well. Gets kinda hollow?

I can't figure it out, gonna try grounding the pressure sensor and see what happens, if that don't work then i am truly lost.

It is somthing eletrical, the engine itself is perfect, runs great. Under 3800 the only issue is the random timing changes that i can't figure out, otherwise it is great.

Gonna have to take a break from working on it anyways, need it for my sanitity also but mainly since i will be getting the last part for my MR2 and will be spending the next few days at least getting it ready for the dyno next week.

satch

iTrader: (1)

Might be poor compression due to a faulty apex seal.

Texas_Ace

iTrader: (18)

Nope, compression is good, tested at right around 100psi, didn't get an exact number just kinda glanced at it but that is not the problem.

Also, it is perfect under 3800, WOT, part throttle anything. ONLY above 3800 does it have a problem.

If i WOT from idle it revs and sounds perfect till exactly 3800 then it instantly changes to a differnt sound and loses power. I can safly say it is not mechanical, it is somthing eletrical.

I might grab a quick video if you think that will help.

satch

iTrader: (1)

Did you end up grounding the boost sensor properly? Are you completely certain the injector plugs are mating with your secondary injectors properly?

Texas_Ace

iTrader: (18)

Was just about to try grounding the sensor when the rain started up again, i will try that tomorrow before starting on the MR2.

Yes, the plugs are secure on the injectors and the contacts are clean so as sure as i can be about that.

This is really starting to drive me bats.

satch

iTrader: (1)

The light green wires which supply the ground signal from the ECU to the injectors are a straight shoot from one to the other with no intermediate connectors involved I believe so checking those two wires (ones to secondaries) should be easy though the B/Y wire starts out as one and is spliced into four and there might be a possible issue there but I think you stated your secondaries are receiving proper voltage though the question remains are they receiving it in a constant fashion.

Texas_Ace

iTrader: (18)

I really tried to understand what you just said, i really did but i am totally lost. A little grammer goes a long way lol

You want me to check somthing having to do with the light green wires on the ECU but what i can not say.

And somthing starts as 1 and is then split into 4

satch

iTrader: (1)

And a thanks to you as well and I enjoy my seat in the back of the class.

You mentioned that you believe your problem centers around an electrical issue. Chances are you believe it is related specifically to the secondary injectors. There are only two wires which feeds each injector. One is voltage, which is B/Y, and the grounding source, which is provided by a light green/striped wire.

The ground wires are a single uninterrupted wire which has the injector on one end and the ECU on the other. This is why I refer to it as a "straight shoot." Checking the condition of these ground wires should be relatively easy and thus remove one item from the equation.

The voltage wire comes out the emissions plug/connector (FEM-02) as two wires which converges into one wire. This one wire leads to the front primary injector. Before the B/Y wire arrives at the front primary injector the wire veers off via crimps in the wire as to feed the other three injectors. An issue could be these crimps are not up to par or there is a break in the wire between the crimp and the injector itself.

Since you tend to believe the primaries are working as required then the condition of the B/Y wire up to the point of the crimps is in proper shape.

Texas_Ace

iTrader: (18)

Thank you, MUCH better lol. Now be sure to work on your home work and turn it in on time tomorrow LOL.

See that i understood perfect and i think you have a point. I am 99% sure it is an eletrical issue of some kind, what or where it lies i am not sure but it somehow only causes problems when the secondary injectors should kick in.

The crimps are possible, the harness looks to be ok but it IS 23 years old afterall and has been moved around quite a bit during the engine swap.

I will try omh'ing out the wires and see what that tells me.

Texas_Ace

iTrader: (18)

Ok, i just omhed out the wires to the secondaries.

The green wire on both is perfect, no resistance. But the strange part is that i get a little connectivity to the other wire on the injector clip to the green wire on the ECU, like 1k omhs but it is still a slight connection. Same on both of them.

That normal? And no the injector is not hooked up.