ironing out my powerband

[daeron]

Okay.. this is a problem that I had before I did my headgaskets. The bad hedgasket made it worse; repairing the bad headgasket made my car run ALOT better, but it still seems to putz out at mid throttle.

 

1987 EA-82, SPFI.

 

For the purposes of this post, "full throttle" is not WOT, "mid throttle" is not halfway open on the butterfly.. I am speaking in relative terms.. IE, full throttle is the point where, you can punch the pedal further, but you arent getting any more acceleration.

 

It seems to overcome its difficulty whenever I push it to full throttle.. (NOT WOT mind you... just "full") and I am trying to track it down. it just loses power at mid throttle acceleration.. I mean, loses it, almost seems to starve for fuel when I hit the gas, unless i hit it far enough. Off idle response is not the greatest, either. I am running 93 octane fuel, but I cant rule out pinging because the thing has plenty of other noises that keep me from being able to say with confidence that I don't hear anything that would lead me to believe it was predetonating.

 

The plugs could probably use renewal, but they arent too bad. Less than two years old, but they seem fine. I have to pull them and see what they look like.

 

Fuel filter has been changed lately

Cap, Rotor, Wires have been changed lately (and they look good, and the screw is intact)

Timing is set dead on, 20* BTDC per FSM procedure

check the fuel filter pickup screen, no problems.

Checked TPS function and idle switch, no problems

changed O2 sensor, but disconnecting it makes no difference in my run condition.

Checked MAF function, and changed it anyhow.

Cleaned IAC

checked CTS.

 

Now, when I went to check my CTS at cold temperature, I inadvertently grabbed the BODY SIDE plug first and checked THAT resistance value.. and got 2.3K ohms!!!! why?? The vehicle was off at the time. I checked the resistance value of the CTS itself and it weighed in at 1.75K ohms (the car is somewhat warm, not FULLY cooled off yet... estimate at about 95 degrees fahrenheit. Air temps are in the mid eighties down here today.)

 

I need to run a D-check, but now I am debating the validity of any D check I have run in the past because I read my FSM in much more detail than I have in the past. Apparently, I am supposed to warm the car up, turn it off, connect the green plugs, confirm that the pump is cycling, fully depress the accelerator pedal, return it to half throttle position for 2 seconds, then fully release it... THEN start the engine. If the CEL goes out (as it should when the engine starts) then I am supposed to drive at speeds greater than 5 mph for a minute.. ensure the engine reaches speed over 1500 RPM, check the CEL for blinking, and if its blinking... This is where I get lost. I have nothing in memory, never had a CEL come on.. so I just pull over and check the O2 lamp, right?????

 

All I ever did before, was warm the car up, plug the green connectors in, make sure I ran the engine over 2 grand for a minute, until the CEL blinks, then read my codes.

 

So, why is that last paragraph I wrote, so much shorter than the one preceding it? What all do I have to do to ensure a good D check test? Also, why am I reading 2.2 K ohms on the harness plug for my CTS? is this normal? that was with the key off, btw.

 

This issue has me totally stumped. I have checked everything but wiring... and it just CANT be wiring, i dont have the giveadam to go through all my wiring..

 

anyhow, will run D check as soon as I get a decent answer on that and willcheck CTS (again) in a little bit.

 

thanks all.

[Zebisko]

Just wondering, why are you running 93 octane? Have you always done that?

[daeron]

i ping if i dont. at least, I did before the HG, and it always did for my brother while he drove it. I honestly wonder if that might be what i am experiencing now... but I dont hear any noises that would typically be associated with it, and it also has the odd off-idle stumbling..

 

the stumble is almost like the timing isnt set quite right, but I did it with a light. I simply mean that, it is a stumble that was worsened as the tmimng was adjusted away from spec.. i dont know if i could advance it any more??? might that help? ignition timing is one thing I don't quite grok yet. I understand how the flame kernel takes X seconds to travel across the combustion chamber and all, where the entire combustion storke gets quicker and quicker at higher RPMs.. i just dont really understand how it all comes together well enough to start tweaking it.

 

Are my posts too rambling and difficult to follow? If so, please speak up and say so... I won't take offense.

[Phizinza]

They are a bit long for a half simple question.. But, sometimes more info is good.

 

I don't have an answer to your question. I noticed the EJ is A LOT smoother then the old EA. I have noticed a mates EA82 got a lot better/smoother power when he fitted the weber. But it also uses a lot more juice now.

[daeron]

Thanks, I like to try to avoid having extra questions to answer. I'm trying to make it more simple, too, without the involved stories, and just the facts..

 

In short, I cant believe that I am actually asking how to run a D check test, but the stupid book now has me questioning whether I have ever done it "right" or not...

 

as for mt CTS, i would REALLY like to know why the harness reads that kind of impedance.. something tells me that I may have found a problem. it shouldnt have any continuity, to the best that I can figure...

 

Eh, I'll figure it out.

[Bucky92]

You know...Bucky does the same thing whenever his plugs go bad...Lucky for me plugs are cheap ( yes I use NGKs ...in my cars and in my dirtbike)cause I have to replace them at the very least...once a year sometimes twice...depending on how much he is being driven...He has one cylinder ( number 3) that likes to run a tad hotter then the rest...someday I should have a compression test done.. I know this cause 1,2,4 plugs will have normal wear but 3 will be white white and the electrode will have 3 times the wear of the other 3.

 

do you have a drop in fuel mileage? can you smell raw gas out the exhaust ( not heavily) These are just all the symptoms Bucky gets when that plug starts to go. I never felt the urge to delve into the problem further cause it never bothered me to much and he has been doing it since I bought him...just part of what makes Bucky ..Bucky:grin:

[hooziewhatsit]

For D-Check, I thought if the CEL came on blinking, that meant 'nothing is wrong'. If it comes on solid (like it does for me), it means there's a code, so stop and read it.

 

As for your stumbling issues... is it speed dependent or RPM dependent? If RPM, almost sounds like a bad TPS, which you say you've checked...

 

Oh yea, does this happen cold & hot?

 

-Dave

[Gloyale]

 

as for mt CTS, i would REALLY like to know why the harness reads that kind of impedance.. something tells me that I may have found a problem. it shouldnt have any continuity, to the best that I can figure...

 

 

You're measuring the resistance of that circuit of the ECU

 

The Black w/Red(BR) wire should have full continuity to ground. The White w/black(WB) wire should have a similar continuity to ground as it does with BR wire.

 

1.75 ohms for CTS? that is nearly full conductivtity? that is way low? the CTS should measure as follows:

 

temp=resistance

 

14f = 7-11.5k Ohms

68f = 2-3k Ohms

122f = 700-1000 Ohms

Runnning Temp for D-check(approx. 190f)= MIN. 100 ohms.

 

100 Ohms is the lowest resistance value the CTS should ever have even at running temp.

[daeron]

You're measuring the resistance of that circuit of the ECU

 

The Black w/Red(BR) wire should have full continuity to ground. The White w/black(WB) wire should have a similar continuity to ground as it does with BR wire.

 

1.75 ohms for CTS? that is nearly full conductivtity? that is way low? the CTS should measure as follows:

 

temp=resistance

 

14f = 7-11.5k Ohms

68f = 2-3k Ohms

122f = 700-1000 Ohms

Runnning Temp for D-check(approx. 190f)= MIN. 100 ohms.

 

100 Ohms is the lowest resistance value the CTS should ever have even at running temp.

 

I always forget to MENTION the range of the multimeter, sorry, the CTS was 1.75 K Ohms. at about 90-95*. sorry

 

As for your stumbling issues... is it speed dependent or RPM dependent? If RPM, almost sounds like a bad TPS, which you say you've checked...

 

Oh yea, does this happen cold & hot?

 

-Dave

It is neither, it seems THROTTLE dependent.. if I am already going at say, 3K rpms, and give it *some* throttle, it seems to go bleah..... I have to give it plenty of throttle. As I said in my first post though, its not the position of the gas pedal that makes the difference (like it would be with a bad spot in the TPS) It is the amount of accelerating that I try to do, the throttle position relative to where I would need to hold it to cruise at current RPM.

 

Judgin from the symptoms, my first guesses were the fuel pickup or the TPS. the TPS checks out, and that was really just to rule that out anyhow.

 

After that, secondary diagnoses would be Fuel pressure or air flow meter. Ive changed the MAF, and have not checked fuel pressure. Guess whats next?

 

Oh yah, while I am at it, I've heard of people taking the boot off of their TB to watch the injector spraying.. I take it that this is something done while the engine is NOT even TRYING to actually start?? (since you would be flowing nothing but unmetered air into the car?) I feel dumb, but I've been trying to figure out how you get to watch the spray pattern on your TBI car for many years now... just never asked anyone. I just pop the boot off, have someone crank the engine over, and watch, huh?

[GJTaranto]

bump, im watchin this like a hawk, im having similar problems.

[Numbchux]

go EJ...

 

 

 

in all honesty, I'd check the basics, plugs, wires, cap, rotor, air filter etc.

[Loyale 2.7 Turbo]

... I have noticed a mates EA82 got a lot better/smoother power when he fitted the weber ...

 

Absolutely True!

[daeron]

go EJ...

 

 

 

in all honesty, I'd check the basics, plugs, wires, cap, rotor, air filter etc.

 

Need $$$ for plugs.. the wires I dont doubt, cap and rotor MAYBE... i popped the air filter box open the other day, so it wasnt sucking though it, and it made zero difference. fuel filters been changed, but I probly ought to do that again anyhow because ive run this tank dry a couple of times. My old man is big on never letting me forget that running a tank down to empty sucks all sorts of crap off the bottom that it ordinarily wouldnt...

 

I HATE being broke. and a fivespeed swap would SOOOO come before an EJ swap......... but not in my rustbucket! I dont want to bother fixing all that crap, since it goes under the windshield and all.... This car is ultimately destined for the crusher, i just want to have a good running engine, dammit! Its hard enough to defend this car to people when I can honestly say "yah, she runs like a top!"

 

so anyway, to restate.. i need to get a fuel pressure gauge on the rail somehow (heh, "rail" on a TBI ) and I need to examine the spray pattern of the injector... I may well have a clogged nozzle. how would I fix that, can I just take the injector out of the TB easily enough?

[daeron]

I have a question about all this...

 

What are the chances that my charcoal canister is somehow just causing a hugeass vacuum leak internally?? what would I want to do to CHECK this theory, just pinch all those vacuum lines shut or should some be connected to each other?

 

I've never done any vacuum line or smog equipment removal, because I have never had any problems with it. I am just looking for a way to rule out the possibility of massive vacuum hemorrhaging within the canister, and as far as I can tell simply pinching all the lines should be sufficient to check that possibility.

 

The reason this comes up is, I leave my factory cruise on all the time. Today while driving around, I tried turning it off to see if it altered my problem any, and it seemed like it *might* have gotten *slightly* better.. and operating the AC controls (vacuum switch) seems to be a burden on the engine as well.. (causes hiccups, etc.)

 

Tomorrow I am going to try to get some video of the engine doing its chug-chug missing thing, and see if THAT helps anyone point me in the right direction.. sometimes I start wondering if somehow I am having a MAJOR detonation problem.. heck sometimes it seems like it might be just about anything under the sun.

 

I hate these problems.

[GJTaranto]

Ha, funny you said that, because I had a #35 CEL code, I removed my charcoal canister/purge solenoid valve/associated vacuum lines and capped off the openings and I think it has gotten better. Not to mention I threw a bottle of Chevron Techron (concentrate) in my gas tank and I think it also improved my situation.

[dhise]

One thing my Loyale will do; if I don't have the gas cap completely tightened, it will get moisture in the tank and run like crap when it happens. I don't know what it is about the fuel filler area, but mine seems to attract water like a magnet!

 

-Doug

[daeron]

One thing my Loyale will do; if I don't have the gas cap completely tightened, it will get moisture in the tank and run like crap when it happens. I don't know what it is about the fuel filler area, but mine seems to attract water like a magnet!

 

-Doug

 

I laughed out loud about this... I don't think your problem has anything to do with mine, but your comment about attracting water rang a few bells!!!