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Gloyale

Turbo Cams/Non Turbo Ea82? Update, full story

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Does anyone have any experience with this?

 

I recently neutered my Turbo wagon. Installed high comp(9.5) pistons, mounted the MPFI heads with oil and water ports blocked off, and bolted on a Spider intake and spliced in jumpers for the TPS, CTS, and idle solenoid. Along with some other creative PCV routing using and early XT snorkus. Anyway......

 

 

It runs like ABSOLUTE GARBAGE!:confused::mad::-\

 

Symtoms: Lumpy idle, but fairly steady. acts like it is misfiring, but will rev. smooths WAAAY out above 3500 for the most part. But when you drive it, there is no Umphhh. Sputters and struggles to build RPM, gains some power and smooths out in 1st after 3500 rpm again, but will not push second.

 

 

New parts: Freshly rebuilt longblock, new Fuel injectors, Fuel filter, PCV, plug wires, cap, rotor, almost new plugs from old motor

 

Swapped w/known good parts, no change: identical ECU, Disty, MAF.

 

 

It has brand new rings, bearings, and completely uncracked (expert welded) heads.

 

I have sprayed all around the base of intake and all hoses with starter fluid and no vacuum leaks.

 

No codes.

 

 

 

So my question now is, would the turbo cams really be this bad in an NA motor?

 

Or is it the fact that I am using a turbo ECU on a non turbo motor?

Edited by Gloyale

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Does it have the right timing curve for a 9.5 CR engine or is it running over advanced thinking its got 7.7 CR and the knock sensors pulling it back ?

 

If you have a late hotwire AFM engine I'd be running the NA computer , if its an early flap AFM I'd be running the early NA EFI computer and mechanical distributor .

 

A .

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Also from memory the turbo cams are 14-56 56-14 where the NA ones are I think 16-60 60-16 .

 

You should look at late USDM NA Spider engine cams because I think they are 20-60 60-20 , always helps to run a std set of components and those Spider ones are supposed to be it .

 

Cheers A .

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Gloyale,

 

I did something similar with my 1987.5 XT Turbo (castrated to NA EA82). I have been having similar problems. I keep finding a glitch here or there, but it's still not running well.

 

Mine was similar, idle well, rev fine but definitely lacking some serious power, i could get it to move, but not drivable.

 

I retained NA cams on mine though, so that's not causing it for me. Though I have no reason to think this, I would think an NA EA82 would be drivable on turbo cams.

 

I'm sure you know more about this than I. 1987-ish vehicles can be annoying. There were some quirky differences between 86/87 and 87/88 years. At least for the XT's and some other EA82 stuff.

 

Verify the year/EA82 style of the ECU?

 

I assume you checked fuel, spark, timing, disty is lined up properly, etc?

 

I really don't know what to think, but i'll be trying to do something with it later this summer. (like EJ swap!!?!???)

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Also from memory the turbo cams are 14-56 56-14 where the NA ones are I think 16-60 60-16 .

 

 

So this is all in an 89 GL turbo wagon. No longer turbo. Tried 2 different known good turbo ECUs

 

Spot on about the Turbo cams being 14-56-56-14. That indeed is the cam I am running.

 

SPFI are 10-54-49-15.

 

N/A XT mpfi (what the spider intake would have been on) is 16-60-60-16

 

So the turbo cams fall right in the middle of both those NA cams. So I don't think it is the CAMs

 

 

 

My new idea, is I am goin to try to jumpering the boost switch to trick the ECU to think it is under boost and needs more fuel. <<<<<<this was dumb......87+ systems don't use the boost switch for ECU, just for the stupid dash light.

Edited by Gloyale

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Reading the O2 sensor voltage/observing the O2 light may provide some clues about mixture strength.

 

I would advance the ignition timing 5-7 degrees and see what happens.

 

A non-turbo PCV may be worth a try.

Edited by naru

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So this is all in an 89 GL turbo wagon. No longer turbo. Tried 2 different known good turbo ECUs

 

Spot on about the Turbo cams being 14-56-56-14. That indeed is the cam I am running.

 

SPFI are 10-54-49-15.

 

N/A XT mpfi (what the spider intake would have been on) is 16-60-60-16

 

So the turbo cams fall right in the middle of both those NA cams. So I don't think it is the CAMs

 

 

 

My new idea, is I am goin to try to jumpering the boost switch to trick the ECU to think it is under boost and needs more fuel.

 

There is also a pin on one of the wiring harness connectors for the engine that is a "turbo ID" pin. I believe grounding it fools the computer into thinking you are driving a turbo engine. If you swapped out to a higher compression, the computer may be using the wrong fuel map?

 

Unfortunately I dont have my FSM in front of me to tell you what pin on what connector.

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Hope you post back what you find out. If you have a pin number or details on this boost switch, that would be AWESOME. I think I swapped an entire NA manifold so I won't have the boost switch connector unless it's not part of the intake wiring manifold.

 

Maybe it's that joker on the p/s strut tower?

 

Have you tried an N/A ECU, I think that's what I have now. I believe the 87 wiring was really close between turbo/non-turbo XT's. Have you checked the 89's?

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There is also a pin on one of the wiring harness connectors for the engine that is a "turbo ID" pin. I believe grounding it fools the computer into thinking you are driving a turbo engine. If you swapped out to a higher compression, the computer may be using the wrong fuel map?

 

Unfortunately I dont have my FSM in front of me to tell you what pin on what connector.

 

Could it be pin 28, Black/yellow wire labeled as "identification of specifications" in the FSM chart?

 

In 89, there were no non-turbo MPFI GL's and there weren't any turbo XT's, so for 89 FSMs they don't specifically state *turbo/non-turbo* discrimination.

 

However a browse back to the 86 FSM reveals a pin on there ECU labeled *turbo/non-turbo*, and it is also a Black/yellow wire.......interesting......the pins and whole ECU are different, but perhaps this is a clue to wire color on the 89 ECU.

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compare 1989 XT and 1989 Turbo wiring?

 

i don't recall seeing a pin like that on my XT Turbo, but maybe I missed it.

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compare 1989 XT and 1989 Turbo wiring?

 

i don't recall seeing a pin like that on my XT Turbo, but maybe I missed it.

 

89 XT FSM also shows pin 28 to be a Black/yellow wire labeled*specification code*

Edited by Gloyale

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Crap. 87 FSM shows pin 28, Black/yellow wire to be the CA/49 state discrimination. Apparently they got less specific with the wordage in 88 and 89, but it is the same ECU, pins, wires, etc......so no go. no turbo/non-turbo discrimination on hotwire MAF systems. Damn.

 

I may have to actually get a non-turbo ECU from an 87+ XT:mad:

Edited by Gloyale

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new train of thought.

 

 

The *new* injectors I used are actually 80's nissan Maxima injectors.

 

They are identical to the original GL turbo injectors, and were rated at the same flow. Same color and appearance.

 

Still, somehow the whole problem seems to be not enough fuel. It is running really lean, popping through intake, and stumbling all overitself with no power. But, oddly, resists stalling out, seems like it *wants* to run better, just won't.

 

Timing belts are correct, ignition timing correct, tried a new fuel pump today.

 

Compression is good in all cylinders 160-165.

 

I am officially stumped.

 

Gonna try the old intake and injectors tommorow.

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Popping through the intake screams incorrect cam timimg

 

 

And yes you would be much better off running a NA ecu.

 

 

Yeah, but these cams are very close, a bit milder, than the factory Non-turbo XT cams are.

 

That is basically what I have created, SPFI block, with MPFI heads and a Spider intake.

 

I think if it's not the injectors (i'll find out by swapping back to the non-spider manifold with the old injectors in it) then it must be an ECU issue.

 

Who's got a N/A 87 1/2+ XT ECU.

 

It's either that, or rewire an use an old Flapper MAF and ECU set-up, and ground out the *non-turbo* pin. A MAJOR PITA

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Do the Nissan / OEM Subaru turbo injectors have a higher flow rate than the N/A injectors? If so, switching back to the N/A injectors may actually make your problem worse, IF it is indeed running lean. The turbo ECM will have compensated for higher flow injectors by turning down the non-boost injector pulsewidth. If you combine that with lower flow injectors, that will actually make the lean condition worse, I think.

But, if it's running rich instead, that would help by leaning it out a little bit.

 

Get a can of carb cleaner, starting fluid, brake cleaner, etc, run a good-sized vacuum line from the intake into the cab, and have an assistant cap it with his thumb. Go for a drive, and have said assistant spray the juice into the hose while driving/ creating the symptoms. If the hesitatioin/bog/running problem lessens, it's lean and needs more fuel. If it gets worse, it's rich. If it doesnt change, it's likely it's not fuel-related, possibly timing or mechanical.

 

+1 on possible cam timing issues if it's popping back thru the intake.

Are the sprockets different between the turbo / N/A cams? Alignment dowels in different spots?

 

Excessive back-pressure would cause it to stumble and hesitate as well... especially on a MAF system.

 

Just some thoughts.

 

88RxTuner

Edited by 88RxTuner

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Easier to remove(and plug) the vacuum line from the FPR for a temporary enrichment test.Pinch the return line for even more fuel.

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i have some XT ECU's, but not sure what years. i think i have a 88+ NA, but not positive. i went through this last summer and don't recall what all i have. i'll be helping a friend with his car tomorrow, if i remember i'll try and snag my XT ECU's and post part numbers.

 

if i have one you can just try and send it back, buy it from me, use it while you look for another, whatever you want to do.

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Sorry, I am certain that you know better, but the simple things still have to be asked:

Did you leave the green ECU connectors connected?

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So, I should update.

 

And fill everyone in on the *full* story of this engine.

 

So, this is a freshly rebuilt engine. I had it toghether, with a turbo on it, for all of about 50 miles. Drove it down to a local 4x4 spot, waded through a river channel I have crossed before, and the nose sunk like a rock.(someone with 35" boggers chewed out a big hole)

 

I shut her down, no hydrolock. But the car was submereged for about 3 hours til we could exctract it. The water forced it's way past all the seals into the engine, and transmission (4eat)

 

So I tore down the engine, inspected the rods for bends, and put her all back toghether, this time deciding to ditch the heat problem prone turbo, and run NA, so I put in some low mileage SPFI pistons, with the fresh rings.

 

I cleaned as much of the milkshake oil out of it as possible, including removing hte oil pump, and filling the pump housing with WD-40. Then, after fully assembling motor, I pulled the Pressure relief valves out of both Cam Cases, and primed the oil pump with a 12mm socket on the pulley and an air ratchet. Pumped until all the oil squirting from the heads was clean.

 

SO..............

 

I got to thinking......popping through intake.....hmmmmmm.....tight valves? Could be the Hydro Adjusters are stuck solid and not letting the valves close? Kinda like an opposite TOD issue. Come to think of it, there was not a trace of valve clatter.

 

So I ran a about a quart of some special Diesel engine detergent/friction release stuff I got from the Diesel mech next door.

 

Seemed to help, alot, the motor now revs smoothly, not so much popping. I was able to get her up to about 50 mph, and into 3rd gear, but still lacking power and popping a bit. I am hoping another treatment with that stuff will help.

 

Any further lack of power COULD be from the differences in the NA and Turbo ECUs.

 

 

 

On a side note, after flushing 5 times, to the tune of almost 100 bucks of Dex/Merc, the trans fluid finally looks more like ATF than Strawberry Quick!

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So........

 

I may have solved it.

 

Problem seems to be the injectors. As I said, they where brand new early eighties Nissan Maxima injectors. Supposed to have the same or slighlty higher flow rate. Well they don't work with the stock ECU.

 

I swapped back in a set of used Subaru EA82 turbo injectors(way easier with the spider) and the car runs fairly normal. Still using the turbo ECU and Cams!

 

It runs well enough now to finish the exhaust, put a good O2 sensor in it, and tidy up the wiring. Then I have to put back in the interior(i pulled it all after the *swamping*)

 

At that point, if I can re-evaluate any further needed tune up, and possibly swap in a Non-turbo ECU

 

 

Again, for a conclusion to the Cam issue, it seems that it runs pretty well on the turbo cams without a turbo.

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