So after a long sitting(all winter into spring) i finally slapped all my parts onto the car. 87 TII, RevII exhaust, BNR Stage 4, RC 750 p/s, Rtek 1.8, emissions removal, and other stuff that i feel would not effect this. After the reinstall of the parts and first start up i thought the cutting out was due to the Bee R Rev limiter, as it seemed to be doing it right where i had it set. So then i tried to drive it... NOPE. Getting a HUGE stumble/hesitation. So today I unplugged the rev limiter and im still gettign the same thing. I went right to the TPS hoping that was my issue, nope... well withing spec, using the Ohm test. Next, grounds. Ran brand new grounds from the ecu to the battery, still nothing. checked and cleaned all other grounds.

It will idle fine, but sometimes just die, AFM? not sure have yet to test that. No fuel leaks, no vacuum leaks. I will post a couple videos below. There doesnt seem to be just one RPM range that it does this. If i blip/stab the throttle i get no reaction really, except my boost gauge does respond, i tried to get both the tach and boost gauge in one shot in the video.

I feel I am so close to getting this thing driving, yet im lost... please help. ill try to provide any more info i can if needed.

Satch? Hailers? Aaron?

 

It free revs just fine? And is the charging system still good after sitting for a lengthly period of time? Alternator should output close to 14.4 volts immediately after starting (might drop a bit afterwards due to heat). You can replicate engine load by unplugging the TPS and disconnecting the vacuum hose to the Boost sensor.

 

it does NOT free rev fine but it free revs better than if i try to drive it. ill go check the alt output right now. will report back momentarily.

 

ok, so could an overcharging alt be an issue? i know its not a great thing in general but in this scenario could it be causing my issue? i was getting no less than 16v from the mazda, just to check the meter itself i threw it on my passat and im getting a steady 14.4-6 from that.

 

never heard of an overcharge causing a stumble in my life.

if it wont revv over a certain rpm thats typically an ignition timing issue being too late.

can you use partial throttle to revv it to redline? <-- might not be a good idea if its all cold.

 

breaks up under partial throttle as well

 

check timing.

and listen for a hissing vac leak. maybe a little carb cleaner can help you out here.


does the Rtek allow the factory ecu to go into warmup mode? im not too familiar with those. it might be worth it to try and keep the motor alive with partial throttle until its warm and see what happens.

are you sure all the remaining vac lines are hooked up correctly? take a look at these pics i posted in this thread. its all the stock setup. make sure that what you have left matches.

https://www.rx7club.com/2nd-generati...stion-1062966/

 

only vacuum lines left are boost sensor, blow off, and injector air bleeds. Rtek eliminates AWS. whether cold, or fully warm i get this issue. i dont think my timing would throw itself off from just sitting...

 

un likely that it would from sitting but its wroth a 5 minute look.

any leaks at the manifold? what about a loose charge pipe?

not to be a dick, but you sure you got the right coil(s) going to the right plugs? i once got that backwards. car ran like poo

 

all piping is tight, yes coils are on right plugs. couldnt find my can of carb cleaner to search for leaks today thats on the list for tomorrow. im trying to gather some ideas of where to look when i go back out tomorrow.

 

Even if it's not the cause you should still address the 16 volt output by the charging system. Perhaps you could unplug the output cable and briefly check to see if the engine runs better at least while idling.

 

Yah, solve the overcharge issue. I once had a loose plug at the alt and got about 16-17v. these are internally regulated alternators so you'll have to get it rebuilt if the regulator is toast.

2x check that your TPS sensor is reading correctly. hot idle is 1K resistance, 5K at WOT. and the throttle rotor will stop touching the TPS plug long before you get to WOT. not sure if you kept your thermowax valve or not. If you didnt, then you can set the tps to 1K cold. wont make a difference.

i hear that the block off plate for the unit below the BAC commonly leaks...i forget what its called. not sure if you have any rtv on there or not.

You can use wd-40 if you want to test for vac leaks, but just be even more careful than you are with carb cleaner.

one thing to check with carb cleaner, is spray a little directly into the intake at the filter with the car running. if you have a vac leak that will tell you quickly "YES/NO" on a leak in general. the idle will smooth out suddenly after a slight delay for the fumes to make it into the intake tract. after that you can start chasing it to a specific hose. IF its a boost/vac leak.

also a home-made boost leak checker might be good for you to make. about 10 bucks. if you do this, take some soapy water, like dawn dish soap in a spray bottle and spritz it around rather generously. in the airplane world we call this "Snooop." it will bubble up if you have a boost leak. NOTE: this is only for the boost test. I know that the same passages see boost and vac, so what i mean is, this is only for when your intake path is pressurized using a tester like the one below. otherwise it will suck in a bunch of soapy water.

Boost leak tester
How To: Boost leak tester for $5.02 - evolutionm.net

i was going to make one, then i stumbled on the leak in the process. i think the HT-18 inlet is 60mm. thats like 2.38in.

if none of that shows anything, id check your plugs and make sure there wasnt some manufacturing issue with them, like one was missing a ground or something ridiculous like that. id also hit the plug wires with a multimeter just to make sure the resistance is within spec.

lastly if i had a long hosed' compression tester id do a fast compression check. just make sure you are getting even bounces.


are you sure you got all your grounds correct and back on when you were working on the car? ECU ground could cause all of this.

 

all block off plates are SEALED copious amounts of RTV were used so i wouldnt need to do it twice.
I know all about the TPS adjustments. Almost anything post WWII is internally regulated i wouldnt rebuild, id just get a remanned from the parts store.

ECU grounds are literally brand new today(straight to the battery), only grounded pins 3A and 3G though, maybe ill try grounding every single one thats in there...

 

was able to find a cheap ECU, once that shows up ill throw it in real quick. wondering if i burnt something up while de/resoldering the rtek.

 

soooooo i must have burned at least one connection in the ECU during install of the Rtek. Threw the new ECU in just now and she idles just fine, and free revs fine. Havent moved it yet as its still in a few pieces. Hopefully driving it tomorrow. I got ahold of the guys at Pocketlogger and will be sending the ECUs to them to either move the 1.8 to the good ECU or just going with the 2.1 instead.
Bittersweet that that was the issue, glad it was an easy fix, but bummed that my soldering skills arent what they used to be i guess lol

 

I made the mistake of just ordering the Rtek chip.
After trying to tackle it I gave up.
I 'used to' be able to see stuff that gadddamn small...(now I know why most electronics are made in "them there countries"..lol..Small hands!)

 

Yeah, my fault, oh well. Might have found an ecu with a 2.1 and palm pilot. Hope it works out, this car has been off the road too long!

 

If it is who I think it is Dawg,you are in good hands.
He's on my list as a top notch buddy!

 

took her for her first drive today with the stock ECU. Runs great! stayed out of boost due to no real fuel control for all the new parts. New issue which is also pointing to a bad Alternator, when my Taurus fan kicks on it will slowly idle down, then die... oh well planned on getting a new Alt anyway, and ive still got to install the dual belt pulley on it too.

 

2.1 ECU ordered up! On a side note, my "Cooling Fan" light is always on now. I know its because that went bye-bye with the rest of the a/c stuff, im also not running the stock thermo switch anymore either, using the starion one so i only needed one relay to wire it up. So could i just throw that factory wire to ground? or just ignore the light?

 

The Meter fuse powers the idiot warning lights w/key to on. The reason the lights don't come on is because they are lacking the ground signal to complete the circuit, thus you want the Black/Red wire of the cooling fan control unit to have enough voltage on it to preclude the warning light from illuminating.

 

soooo no grounding it then... guess ill just ignore it

 

got the wideband hooked up today, and wire ran for the water temp. quick question for anyone with an autometer wideband. im not sure if its normal to have to push "mode" everytime i turn the car on and have to wait for it to sweep through AFRs? I remember my buddies (different model im sure, this was years ago) would just turn on and go like i feel mine should... It turns on but i have to hit "Mode" before it will do anything, i just get the 3 --- until i press something...

 

Ok so instead of starting a new thread ill continue here. Installed my rtek 2.1 today and ran the set up. Now i have 750/750 injectors, after much tinkering and talking to mike at digital tuning themselves i think i may have an idea of my problem.
Problem: with the preset set to 550/550 or 550/720 the car idles perfect and afrs are good. Now when i change the preset to 720/720 the afr goes full lean and the idle is terrible if it runs at all. Now im thinking my issue may be due to the fact the stock o2 is out right now to run my wideband for testing, so the wire is unplugged and im running a starion thermosensor in place of factory for my taurus fan, factory wire unplugged. Full emissoons removal. No vacuum leaks. Stumped...not sure why it idles great on one setting but not the other...

 

Tired fuel pump, clogged fuel filter?? And only the primary injectors are used during idling so switch from 550 secondaries to 720 for idling should not make a difference.