Powerloss at 3800..
 

From what I can figure out, my secondary ports are opening but my secondary injectors aren't firing..

I don't know how to check that though.

The car loses power and wont accelerate further anywhere after ~3800
ex: driving 65mph and flooring it will jump it up to 5k and then it wont move at all, just stick there.

So, does my assement sound right?

Oh, it also bucked when I was going up a hill at about 60 and then put it down to 3rd gear [this is an Auto btw.], and tried to accelerate [this is when I could most clearly see it was right around 3800]

I read the articles on FC3S Pro, but those are for the T2, so I don't know if they're the same. [Mine's an 87 NA]

..and I have been tending to use cheap gas.
[mostly arco, but 76/conoco more often recently]

Would injector cleaner help?

-Thanks!

The NA does very well on 87 octane.

The ECU brings on the secondary injectors ONLY IF vac is low & TPS is high, and the tranny is not in neutral.

Start by checking the TPS and the boost sensor.
It could be the boost sensor is not plugged in.
The tranny neutral switch could also be a problem.

ha, another auto owner. My Torque Convertor is finally starting to go out. I can't even idle in drive now. I have to constantly pop it in neutral when ever coming to a stop. But I still love it. btw, SS, check your pm.

How do I check them? [We've got a fair number of tools at my house..]
and where are they? [I know the TPS adjustment thing is below where the PS pump would be - I don't have PS]

Thanks!

Does it just hit a wall at 3800? Or does it just seem to have no power after that? IF your secondarys are opening like you said they are, it could just be a clogged exhuast. Maybe your cat took a dump. Also check your air filter.. could be really clogged up choking the motor down.

automatic huh?..have you checked your fluid level(trans)..lately?..they are finicky for that..makes it feel like loss of power..top the fluid off...good luck to ya

na hes having the same problem that i cannot for the life of me figure out.... and im damn handy when it comes to cars... so are al lthe other mechanics i work with at the shop. ive put in a different computer, brand new fuel pump, filter, secondary injectors, took intake off and cleaned, wired my 5th/6th ports open, added grounds to all ecu grounds, battery, fuel pump, and other random places. the secondary injectors are just plain not coming on and the car just hits a wall at 3800 rpm and will not go past. someone todl me to unplug the boost sensor and drive around and see if that helps and if it does then its the boost sensor... im off tomarrow so im going to try that ...

I haven't checked the trans. fluid, but I doubt that's it [It clearly has no power in all 3 acceration gears]

I checked the air filter and it's clean, changed the spark plugs [half the old ones were in the wrong places, but it still didn't help]

but still, the boost sensor, ecu, etc I don't know how to check their operation..

I did try pushing the secondary's open and that was about as easy as it should've been, and I tried wiring them open, so they seem to be working fine. [Plus it makes sense that if they are opening that would hurt my power there.]

So, how do I go about checking things?

Ok, I got out my haynes manual last night, and it looks like the boost sensor is the little black box behind the air filter box, correct?

Should I try Disconnecting that and driving around for a while?

Ok, I just tried:
taking the vacume hose off the boost sensor [didn't help]
Checking the resistance of the TPS [OK - 180~]
checking the other end of the connector's ground [questionable: ~300?]
and that was all I could check, since I don't have time to get to the solenoid resistor, or to test the main relay


So what now? is the TPS's ground too weak?

Next – check the transmission neutral switch.
In the on-line factory manual, fuel & emissions section, there is a diagram of the ECU pin-outs.
Although it’s a pain to pull back the passenger carpet & remove the foot rest panel, all the signals can be checked there.

I have a link to my mirror copy of the manuals in my sig.
Download & print what you need.

Okey, I'll try and do that when I get home [actually my pass foot rest panel is missing a screw or something, because it's not down all the way, so that's not much of a problem]

I'll let you know if that works

Oh, and I'm not sure what my multimeter was trying to tell me when I was checking the ground for the TPS connector - it should've made a noise, but instead it just put out the number 300 [my dad - who owns it - says that in that mode it shouldn't have anything but a 1 or a 0 on the screen?]

The TPS is a varible resistor with a range of ~0 ohms to ~6K ohms.
With the cold start fast idle cam pulled off it should show 1K ohms on the hard idle stop.

As it wears out, it can show drop outs in the sweep from 1K to 5K.
The ECU goes nuts when that happens.

ive got the same problem with my 5 speed 87 n/a. it just wont let it go past 3800 rpm's like the computer just cuts it off when it hits that specific rpm.

Try checking your fuel filter, your inline and ur in tank, then try checking your 2ndary injectors, you can try to listen to the clicking

I'd get a auto mechanic stethoscope or a long piece of thin rubber tubing and see if I could hear your secondary injectors opening (like vietxdragon said) at that engine speed. Your 3800 RPM problem tells me your secondaries aren't coming online... Also, your TPS should read 1 ohm at closed throttle idle. It should sweep smoothly up to 6 ohms on your digital multi meter. You can pick up a used (hopefully tested in spec) TPS for under $40. You can get a brand new for $100 ish. Like sureshot said... the TPS is a source of many problems for these cars... : (

And about your catalytic converter, is it rattling from beneath the car at all??? Did this 3800 RPM problem happen suddenly or a gradual power loss? Hope you fix it soon : )

I meant the ground wire [the other connector - the one going to the car, not the TPS], the multimeter didn't make a sound [which it's supposed to do if there's continuity]
I was touching one probe to the negative terminal, and the other to the pin on the connector that goes to the car

Does this all mean I should try and do something about this [Grounding?] or proceed with the neutral sensor check?

Before I bought the car there was a rattling underneath, but it was only the shield, and they welded that back in place before we completed the sale.

This all happened sometime when I was driving normally [the next time I tried flooring it, I noticed it was doing this - though i didn't know what was going on so it was harder to describe. ]

Oh, and I had the car off while I was doing all the electrical tests [shouldn't matter though? - the grounded wire should always be grounded..]