Help me make it to DGRR! Car will not rev...

[Max777]

Ok, this is a continuation of a previous problem.

The car starts just fine, then idles kinda high, and then the idle goes down and it stays idling. Sometimes the car will die if it isnt fully warmed up. When I try to press the gas at all, the engine just falls flat on it's face and dies.

I have now gotten an RTEK 2.0 for my car and took some logs, however the ECU will not let me disable the MOP for some reason (says "unsuported") for whatever reason.

Interestingly enough, I hooked up the stock ecu and the car started and ran, but would not rev, now that I finally hooked up the RTEK the problem remains. I got some data logs but i dont know how to upload them to the PC?

One thing I noticed is that the AFM air temps and IAT sensor aitr temps varied by 20*F. I dont know if this afects anything on this car.

Some things I did:

made sure there are no vaccum leaks when I reassembled the manifold the second time.

removed emissions, all new vaccum hose, put RTV and bought new gaskets for everything, ziptied vaccum caps, and just generally made sure everything is nice and good.

Tested TPS: on the bench it checked out ok, then I adjusted it with a self made TPS tester yesterday, it was way out...

Tested AFM, here are the results:

E2-Vs terminals: closed: .400K ohms open: 114 ohms

spec is:closed: 200-1000 open: 20-800

E2-Vc closed-open: 279 ohms value does not change between closed/open.

E2-THA: @ ~45*F I got 3,693 ohms, this in alldata specs is around ~32*F, so this value seems in spec.

I tested the TPS that originally came with the car and it checked out ok. I DID buy a new throttle body and another sensor that came with that was bad... so i put the OEM one on.

I will have more info in a bit.

[FerociousP]

with as little time as you have I would be trying as many spare parts as I could... mainly afm, and tps.

obviously its not compensating for you pressing the pedal by adding fuel, so it doesn't know your pressing the pedal or doesn't know its getting air... If I remember correctly the car won't run at all with a bad MAF. Have you tested the tps sweep for dead spots? Tested resistance at the beginning and end of the sweep?

Are you 100% sure you don't have a ginormous vacuum leak? :)

[vex]

Did you hook up the primaries to the secondaries on the harness and vice versa :suspect: not that I have ever done that before...

[FerociousP]

Did you hook up the primaries to the secondaries on the harness and vice versa :suspect: not that I have ever done that before...

is that physically possible?

[vex]

is that physically possible?

Yes

[Max777]

I am pretty damn sure I did not hook them up backwards.

I have an S4 map sensor I borrowed, as well as my original CAS, the one in there right now came with the shortblock 13B I bought, and I was wondering if maybe that could be it?

Would a bad CAS cause this type of problem?

I will call Kevin, Chris Ludwig, Banzai, digital tuning, and a couple other places to check.

If I bought anew TPS, and it didn't solve the problem, can I return it? lol

Man, I really wish I knew how to diagnose stuff better, Tech schools can only each you so much in a semester... :D

[Max777]

Ok, so I spoke to Chris Ludwig, who sold me the RTEK, and it turns out that the unit he sold me was actually an older unit that did not have the MOP feature available. I explained to him how I blocked off my MOP, and trimmed the plug off the harness, and he told me that this might be my problem.

I called DTI, and sure enough, the unit is one of the earlier models which does not feature the MOP delete option. Fortunately, I can order an update chip for $10 and then it should be up to date on all the specs, including the MOP option.

This has given me much relief, and is very likely all that there is to my problem, however this also means that I will not be able to drive to DGRR this year..... :(

Oh well, there's always next year, and apart from this little issue, which was out of my control, I kept my promise to get it done and running by DGGR! :D

If there are still issues after I install the chip, I will update this thread again.


Max.

[Max777]

Here's a video of the car running, sorry for the bad quality, i took it with my cellphone.

http://www.youtube.com/watch?v=4rV8dKq7ALw

[FerociousP]

strip the harness back and splice in the wires!!! I'll send you a pigtail if you need it...

[C. Ludwig]

Worst video evar. :lol:

Seriously, that's not limp mode. Vac leak is what I would guess.

[Max777]

i know it sucks.... oh well, I ordered the chip... (it was only $10 to update)I'm going to get a can of propane or something to test for leaks.... and get a better video camera.

[djmtsu]

Yeah dude, splice the OMP back in, tie it back and roll on!!!

[Phoenix7]

Ok, so if it's not a ginormous leak (at the intake tube) then look at your spark to make sure the leading coil is firing right....I was just twlling someone else about the spark and thought about your problem max....

This is a tough one.

[djmtsu]

Ok, so if it's not a ginormous leak (at the intake tube) then look at your spark to make sure the leading coil is firing right....I was just twlling someone else about the spark and thought about your problem max....

This is a tough one.

I think that isn't the problem. He said the Rtek will not let him disable the OMP, so that part of the ECU requires it to be there.

Without an OMP plugged in- no go!

[Phoenix7]

but it'd go into limp mode without the OMP, no?

[WE3RX7]

without the OMP plugged in, you can still rev the car... just cant drive it...

I'm still banking on TPS issues or MAP sensor...

[Max777]

What Ludwig said, is that I can rev it in the short range of the rpm, but I cant rev it in the "wide" range of rpm. Now, I already made up my mind that I'm not going to DGRR this year.

My chip will be here friday, I will install it, and run the car again, then post the results.

I think that part of the problem is all the adjustment screws on the Throttle body, like the thermal pellet and all that crap....


One problem I also noticed is that my BAC WILL NOT TURN OFF! I posted this before in a diff thread, but no one gave any feeback on that.

Is it possible I have a bad BAC that's contributing to this on top of everything? I will test it friday also, and post the results.

[Boostmaniac]

Does the BAC make a sound when it won't turn off? I hear a small clicking/pumping sound coming from it after I re-installed my engine. It didn't do that before (and my idle sucked ass before).

[Max777]

yeah, it just kinda "whirs" or whatever, non stop, sort of like how a loud fuel pump might wirl if it was continually turned on.

The thing is, this is with KOEO, so the motor is not running, why is the BAC still on, it did not do this before, you're right.

[Max777]

Update:

Got the update chips, installed them, and had no connectivity with the PDA.

Installed old chips, car works fine, but still have OMP Fail code. (removed pump)

I THINK MY BAC BAD on top of this!!!!

All of you guys kept saying "sounds like a vacum leak" there you go! I mentioned that the BAC would constantly "Buzz" and stay on with KOEO (key on engine off).

The car ran a lot better when I unplugged the BAC, and I could rev now, but the timing is off.

In the RTEK, timing reads: (720~780rpm)

T-Timing: -5 degrees

L-Timing: -20 degress

In the FSM, it says timing should be that, but with positive values. When I lightly rev the car, the timing goes into positive.

I tried hooking up a timing light to the L1 wire, conected the "Check" connector to the car, and set timing... I think it still runs rough...

DTI is shipping me another set of chips, so when the GOOD ones come in, I will install them, and post a HD video of the engine running.

In the mean time, does anyone have a working S5 N/A BAC valve?

[NoDOHC]

Unfortunately, The BAC valve is not likely your problem... I am guessing that there is a wire crossed somewhere to the BAC. The BAC should be pulling air in through the AFM anyway, so it shouldn't be a vacuum leak.

The BAC is a solenoid and will operate when it gets voltage. I think yours is working just fine, but getting a signal when it shouldn't.

If you want to test it, apply 12 volts to it to verify that it opens (take it off the manifold and watch the plunger). If it opens when energized and closes when de-energized, it is working properly.

Your timing sounds just fine (I think negative indicates ATDC which is the factory spec).

[Max777]

Well, I will check the solenoid, just found how to test the BAC in the FSM, so I will do that when I mess with the car next time.

[Max777]

Ok, I tested the BAC valve, Ohms resistance reading on the car was 11.2, and the solenoid clicked when I applied 12v to it like it said to do in the manual.]

The UPDATE chip came in, I installed it, and was finally able to select "disable OMP" option on the ECU.

I am about to mess some more with the timing...

[Max777]

Ok, so I still had the revving problem with the BAC plugged in. I unpluged it, and could actually drive the car down the street for the first time in like a year!

Right now, the car will stall out at a stop sign, or when I put it in neutural, it has low revs, etc.

Power steering works, brakes work but need bleeding, clutch works, but there is a whine when I let go of the clutch pedal. (Replaced the throw-out bearing so it might be the pilot or the transmission itself)

So, I need to fix this stalling issue soon, but other than that, the vert is almost ready to go!!! :D

[Max777]

I almost got it!!!

Ok, so I was looking around, and decided to mess with the throttle body.

My "Fast idle cam" was way out of adjustment, at 75* it was between the 30 and the 70 mark. I got that adjusted, then adjusted the gap in the primary butterfly to .018"

After that, I plugged in the RE-Tested and cleaned BAC valve, and all worked great, my car could now rev with the BAC valve just fine, and ran better than my first outing.

My current problem: The engine stalls when I pull to a stop.... this is now with the Timing and TPS adjusted, and BAC plugged in and functioning.

[TehMonkay]

Did you adjust your idle fuel mixture yet?

[Max777]

idle fuel mixture?

You mean the screw on the very top of the TB to set idle? yes

the idle is at around 700~800 right now, it doesnt stay exactly steady, but I tried to dial it in a bit.

I dunno, it runs ok at throttle, but it just stalls and the idle is weak. I think I might have a vaccum leak, but i think the big problem lies elsewhere.

[Max777]

Ok, so with a LOT of searching, I managed to find that a possible cause COULD be the dash pot not being adjusted properly and my spark plugs being foulded a bit causing a bit of a fluctuating idle....

Interestingly, the dash pot and another two sets of screws on the TB are not even listed for adjustment in the FSM, I found that really odd, my Dash pot i think is a bit off, I was looking at it when I readjusted the fast idle cam.

I am wondering about the people however that completely removed their thermowax pellet and no longer have a dash pot...

My car starts, then idles at 3000, drops to roughly 1,400 rpm, and then it will idle if I dont touch anything, but as soon as I put the car in gear it dies.... when I start it back up, it will hold idle but it would be kinda weak. I'm wondering why it would die when put into gear with clutch pedal still depressed? I have a whine when I depress the clutch (new throw out bearing) so it might be the pedal being mis-adjusted too.

When I timed the car, the L1 wire lined right up with the mark, but it didn't quite line up exactly on the trailing side... but I did not adjust it for the trailing side.

[NoDOHC]

You might have something with the vacuum leak theory. Does the car misfire while idling or purr along? If it misfires, it is likely running lean (less than 13.5:1 at idle) due to a vacuum leak letting in unmetered air. Stock RX7s run very rich of stoich at idle.

edit: My '86 would start at rev to some insane rpm unless the shifter was left in gear, when it would start, rev to about 1500 rpm and then settle down to a good idle.

If I had to guess, I would say that your idle setting (reached by placing the car in gear when starting) is too low (not 700-800 rpm, like you think).

[Max777]

Ok, I spreayed some Throttle body and air intake cleaner to test for vaccum leaks... could it be that TB cleaner is not as volatile as carb cleaner?

I could not find any leaks

[TehMonkay]

idle fuel mixture screw is near the map sensor, someone couldve adjusted it to too rich when the car did have a vac leak now you're too rich at idle causing you to stall.

I reccomend adjusting it according to the fsm.

[NoDOHC]

I don't suppose that you have a wideband, but maybe you can use the RTec to read the narrow band O2 sensor. It should be go into the rich region and never leave it until it gets into a higher gear and is cruising.

Obviously a misfire will cause an erroneous lean reading, but you should be able to watch the trend.

Stalling does occasionally happen, if I pull my '91 into gear right after it has come down to low idle (I have set to 600 prm) without giving it gas, it will stall. If it is warm, it won't.

[Max777]

I dont think that my car is supposed to have the idle air mixture screw, it's an S5 model, I think only the S4 had that screw.

As far as stalling goes, my car stalls ALL the time when warm, I would be cruising with water temps over 178-F, and if I put it into N and release the clutch, it just drops RPM and the engine dies...

[Max777]

Hey guys, so I was wanting to know something...

Are the primary injectors supposed to be running at 100% duty cycle when the car is at idle?

I thought that it would run them a lot lower...

also, how many inHg is the MAP sensor supposed to hold? I tried to test it with a vaccum pump and it looks like it wouldnt hold vaccum.

(When I put my finger over the hole, and pumped the vac reading was fine so I know the guage works.

[need RX7]

^That's not right. They shouldn't be running more than 80% at redline, let alone at idle.

[Max777]

ok, i figured out the injector thing.... it was primary injector ratios at 100%, not pulse width. sorry for the confusion.

right now I'm awaiting a new map sensor. After I get it, I will redo some stuff with the intake manifold.