Trying to use 450cc on older CA18ET motor

[KaZ (VaBch)]

Hey all...

I've installed a few upgrades on my '84 200SX, but I can't get it to run now...

What I had before:

T28 Turbo w/ Split Flange Downpipes2.5" Exhaust Stock InjectorsStock MAFNo IntercoolerRunning ~7PSI

What I installed:

Volvo IntercoolerHyundai Radiator & Fans (Fits inside the Volvo Intercooler)2.5" Piping from MAF to Turbo, Turbo to Intercooler, Intercooler to Throttle BodyZ32 MAF Sensor450cc DSM InjectorsCA20E Intake Manifold (Forward Throttle Body Orientation vs Side with CA18 Manifold)SAFCII Limited EditionWideband O2

I was "hoping" it would run...

I've got all the sensors wired and working (I believe). And no leaks in the intake tract...

I had it running a week ago WITHOUT a MAF, it would idle up and down and up and down and up and down (you get the picture) but when we hooked a MAF to it (Z32 or stock) it died. I haven't really been able to get it to run since... I've since gotten a Z31 MAF (similar in size to a Z32, but more compatible wiring), and a KA24 Throttle Body (similar to my stock one but a little bigger).

I tried the Z31 MAF today, and it still won't start. I finally figured out she's a little flooded, and cranked it over with the injectors disconnected and it just turns for a few cranks, then actually starts, runs for like 2 secs, and cuts off (once its used the fuel). If I reconnect the injectors, it starts for a split second, then dies, and I have to repeat the above process.

I've checked most of the sensors, and it should be receiving enough air to idle, but its just getting too much fuel. I even installed the AFC and leaned it out by 50% and it still won't run... =( the 450cc Injectors are a 66% increase over stock (270cc), but the MAF diameter incease was close if not exactly the same (why I went with the Z32 & 450cc injectors). Anywho, I've about given up, and I'm going searching for a stock sized injector tomorrow at a local yard (I broke one taking it out). Any thoughts or suggestions before I do towards getting this thing running?

Thanks,KaZ

[paul_s13]

It doesn't sound to happy does it, it sounds like the safc isn't knocking the duty cycle down enough, also there will be diffrences in the voltages of the maf sensors, maybe finding out what the idle voltages for both MAFs might help.

Maybe try running it with some CA18DET 370's and MAF if possible.

[KaZ (VaBch)]

Good thoughts... I'll probably need to check those items... Do you know if the CA18DET Injectors are high or low resistance?

[boost_boy]

They are high impedance!

[KaZ (VaBch)]

D'oh... Older CA18ET motors use Low Impedence... Crap... Guess I'll need to find another donor.

Thanks,KaZ

[paul_s13]

D'oh... Older CA18ET motors use Low Impedence... Crap... Guess I'll need to find another donor.

Thanks,KaZ

I do believe Ford Sierra Cosworth injectors are low impedence and they cost next to nothing in the UK, also they are about 380cc.

check the RS forum at http://www.rsownersclub.co.uk/

[KaZ (VaBch)]

Well those are not much smaller than the 450cc injectors I already have... I thought the car would be able to handle them, but I guess I was wrong...

Strange thing is it ran rather well that first night we were tinkering with it... but I haven't been able to get it to run like that since...

[boost_boy]

I would try another ecu 1st. Who knows, maybe the ecu couldn't handle the voltage input from the z32 maf as well the Super AFCII or something went wrong. Sounds to me that something just took a crap and the car is now refusing to train anymore.

[KaZ (VaBch)]

I kinda thought that myself... but the ECU isn't putting out any codes... so I'm not sure... I do have a Z31 turbo sitting in my driveway my brother is parting out... maybe I should pull the injectors outta it... any idea what size they are? '86 Turbo.

Thanks,KaZ

[boost_boy]

Back in 1999 when I had my ecu done by JWT to also accept the Z32 MAF, my car started fine for few seconds and then died with no intentions of running again. I put back in a stock N/A ecu and it fired right and ran just fine. Put the JWT unit back in and nothing but rotation. AFM section burned out and will create a no-start condition. And since you are using a super AFC, so go figure.

[KaZ (VaBch)]

I'm kinda lost on your statement there... first half made sense... second half got lost in translation... can you rephrase that? What did you mean by the SAFC?

KaZ

[float_6969]

The way the SAFC works is by modifying the signal that goes into the ecu. It can possibly put too much signal (electricy) into the circutry of the ECU and burn (literally) some of the circuts up.

[boost_boy]

Quote »The way the SAFC works is by modifying the signal that goes into the ecu. It can possibly put too much signal (electricy) into the circutry of the ECU and burn (literally) some of the circuts up.[/quote] You said that better than I did:D. But that could be the case and yours won't be the 1st nor the last.

[float_6969]

You said that better than I did:D. But that could be the case and yours won't be the 1st nor the last.

The question is, are you suprised? I know what I think....Hehehe, JK Dee, I gotta give ya trouble.

[r34 gtr]

wait, wait, wait. dee, you just said the ca18det injectors are high impedance? are you sure about that? ive gotten alot of responses saying theyre low impedance, which is the same as the dsm injectors. there are several people on here using the dsm 450cc injectors with no problems. the injectors must be working correctly if hes getting fuel, right? or could the wrong resistance load on the injectors cause them to remain open or on?

- tim

[float_6969]

I'm pretty sure they're high. You can use DSM injectors, you just have to add a resistor to the circut of each injector to increase the resistance/load/impedance.

For EVERYONES future reference: You can use low impedence injectors on a high impedence system by adding a resistor to the circut of each injector. You CAN'T use high impedance injectors on a low impedance circut. Don't even try, cuz thats a good way to burn up an ecu...

[boost_boy]

CA18DE have low impedance injectors. CA16DE have high impedance injectors hence the need for the injector resistor. Now, the RWD CA18DET have high impedance injectors hence the reason for the injector resistor as well. I can stand to be corrected as I'm too lazy to go into my closet and check the resistance.

[r34 gtr]

ah, ok. when i asked, people seemed to leave out a lot of information. for future reference, which injectors can i run on my ca that i could get for cheap without any modification? rx-7 turbo II are low impedance? the 3rd gen rx-7 are high (?) so they should work alrght? what about a supra injectors?

- tim

[float_6969]

any top feed should work, but I don't know if the plugs will be the same or what the impedance is. So a lot of help I am!

[boost_boy]

RX-7s do work, but you will need their plugs as well because they are different.

[float_6969]

Just do like I did and get a hook up on some brand new, never been used or installed NISMO 555cc CA18DET injectors for 400 shipped from japan.

[r34 gtr]

yeaaaah...im looking for something more like $50 for all 4, shipped if necessary. you forget how insanely broke i am. for and idea, i got my bank balance and it said ive got $59.67 in there. this means if i buy some injectors for 50 bucks, ill have less than 10 dollars to my name..w00t!

by the way, dee, what year and model rx-7 injectors work? and are there any strange cars i might be able to steal from? like the merkur xr4ti?

- tim

[boost_boy]

Tim,

I think you can get them from all turbo II models. The 550s are the primaries and I think the secondaries are 700 something cc. AS far as any other car, I say go to the track on event weekend, catch some of the show boys slipping and help yourself:D (I've seen it happen).

[KaZ (VaBch)]

In a loud evil voice... ITS ALIVE... ITS ALIVE... MUHAHAHAHAHAHA!!!

Seriously though... she's running... it was the AFC settings... I had a brain fart with the switching MAF thing. Darrell in Cali IM'd me off the board and gave me a good smacking of AFC know how... Although I had to fugger with it at first... He suggested a 2 In 7 Out... but that didn't work at first. 2 In was correct... but the 7 wouldn't work... I tried 5, 6, 7, 8, 10, 14, and a few others... some it was ok on... others not. I think everything between 4 and 10 works ok... it would stumble occasionally. In the end I think I have it on 2 In 6 Out... with a 50% decrease at 1000, and it moves up to a 30% decrease around 3000 I think, and from there on out. Moved from 50 to 30 from 1000 to 3400... A/F on the wide band is around 11.0 (more in the 10s really, its rather rich). Oh, and this is on 87 Octane...

Oh, and the clutch is toast... :ylsuper

I was out tweaking things with my buddy (ghetto fabbed boost gauge, AFC, and wideband; him holding the last two, me with the gauge in my left hand...). 2nd good... 3rd good... 4th on the highway, SLIP

So... she hit ~12psi peak... normal she goes right to 10psi... but it fluctuates here and there. This is with no Boost Controller and no BOV. Surge is rather audible... I'll be getting a BOV and controller shortly. I've got some photos, but I need to resize before I post.... thanks to everyone for the suggestions! My brain must have taken a vacation!

Oh, and I did get it working with the setup I wanted...

Z32 MAF & Intake450cc DSM Injectors2.5" Intercooler piping (most places)Volvo IntercoolerHyundai Radiator (1 good fan, 1 bad)T28 Turbo...

:ylsuper

I'm going to bed now...

[KaZ (VaBch)]

She's ghetto I know... but here is a shot...



Anyway, I'm off to bed... its 2:22 AM EST, and I have to be up around 6am... d'oh.

Later Peeps. Thx to all again!

KaZ

[quest]

all the rwd ca18det injectors I've ohm were low imp, between 2-3so were the DSM 450sAll turboII have 550s, primary and sec. Came lo & hi imp, depend on yr

which t28 do you have, volvo ?

[float_6969]

*Applauds

[Nismo1182]

ok, its for sure then? The CA18DET injectors are low imp?

I have a set of 450 DSM injectors that I want to put on soon.

[boost_boy]

I'm going to have to test mine and see!

[KaZ (VaBch)]

What's an "optimal" a/f ratio?

Thanks,KaZ