That damn hesitation thing!!

[boostjunkie]

Well, I've been experiencing that voodoo hesitation thing again. Not like my old car where it would buck but like the power is all of a sudden zapped and then returned from 5000-5300rpms. I've read the NASIOC forums and there are a couple people with WRXs experiencing the same thing. Some of them have pointed out an issue with winter gas and I'm exchanging e-mails with someone who's dattalogging the events on his deta-dash.

So now for the questions:)
1. I know there is a scan tool for the OBD2 cars that can wire into the ecu (by means of a harness) where you can read real-time values (o2, MAF, etc) but is there such a tool for the OBD1 ecus?

2. I'm planning on getting this EMI dual A/F gauge and injector monitor soon, as there could be a possibility that I'm close to maxxing out the injectors . . . Good idea or not?

3. Might look into getting that new S-AFC that just came out. Just like the old one, except it has 200rpm increment adjustments and a knock sensor monitor as well. That is, of course, the problem is in the fuel delivery.

4. The computer's definitely pulling timing . . . is there a way to monitor how much timing is being pulled?

Sorry for the questions . . . It's just that the car drives perfectly, except within that narrow range, yet there is NO CE LIGHT!!

FWIW, I changed the plugs to NGK coppers, 1 range cooler, about 5,000 miles ago, I did the SPG mod, and I was told by Adam that the fuel filter was changed not too long before I got the car. I guess I'll check the air filter to see if it needs to be cleaned.

Any other suggestions/next steps would be greatly appreciated. Thanks!!

Jason

[Legacy777]

Simply put......no there is no monitoring stuff for the OBD1 computers. The only thing out there is the subaru scan tool. I'd honestly be willing to shell out 500 bucks for one, because the amount of info you can gain from it is simply astounding.

I've got similar issues/hesitation......which I don't know if it's caused by a poor auto tranny......or engine.....I would think it's engine......My hesitation is less now then it was when I had my chip in because I didn't do a good job of wiring in the chip, and one of the leads was loose.....so I can't blame the chip. I'm probably goin to try and put it back in, in a couple weeks to see if I notice a difference.

The only other option would be to tie into all the sensors, and have some sort of custom data logger....that you would be able to sort through all the info. major pain in the butt.

I think the gauges are a good idea....don't think it will tell you anything about timing though. You may have to do what I may do is pay for an hours time of a tech....have him bring a select monitor with him, and just go drive the car around....and see what sort of info you are getting back from the select monitor.

How come you went to a colder range plugs? what sort of boost are you running consistantly? Have you pulled the plugs to see what they look like. If they are not reaching their self cleaning temp, you'll have issues....and the spark could be blown out.

Were you getting detonation/pinging issues with the standard plugs? If you weren't.....I'd probably not mess with them. I'd also try and check the duty cylce on the injectors.....see what they are running at your higher boost levels.

[boostjunkie]

I'm running a bar of boost. The car ran really crappy whenever I would boost more than 7psi. When I pulled out the old plugs, they were the bosch ones, so they needed to be changed out (I heard they suck). . . I replaced them with the V-coppers and the car ran silky smooth. Upon inspection of the electrodes, I found no signs of lean run or fouling.

I developed this current hesitation issue once the temps started to get really cold around here. That leads me to believe that:
1. Cold air might be too dense and I COULD be running lean, or
2. The gas stations around here started finally running the winterized gas.

Of course, I could be way off base.

I do know a mechanic that has a snap on scan tool, but he used it for my other legacy, which was OBD2. Do you think he'd be able to use it for OBD1? Is that software backwards compatible?

Now why wouldn't the car throw a CE light?

[entirelyturbo]

I do know a mechanic that has a snap on scan tool, but he used it for my other legacy, which was OBD2. Do you think he'd be able to use it for OBD1? Is that software backwards compatible?

I was told by a mechanic at my job that he's got a $3k tool that can plug into any ECU, period. It can supposedly tell you a/f maps, ignition timing, even compression...without pullin' spark plugs...

I suppose I'd have to tear the passenger carpet up and he'd have to plug it directly into the ECU...

Or does this sound like a bunch of BS? Kinda does to me...

[Legacy777]

Jason,

yeah the bosch plugs don't run real well in the subie motors. When you put the NGK's in to replace the bosch's.....were they the temp range colder plugs? Have you tried a set of NGK coppers and the correct heat range? Do you have any specs on how much colder the plugs are that you have?

Personally.....I would buy a set of plugs meant for your heat range and stick them in........ngk's are cheap and it'd be a simple troubleshooting step.


Other thing with the temps is that you've maxed out your injectors hence causin your lean case.

I would probably say that the tool your mechanic has is for OBD2 stuff. The problem with OBD1 stuff is that it is propritary. Everyone's setup/plug is completely different from each others. No standardized system. code 11 on our cars could mean something different then code 11 in a ford.

I think now.....all the basic codes are the same across the board for all cars.......

If you wanna give it a shot.....it may be worth it to at least try......I don't think it will...but ya never know.


I think the mechanic at your job doesn't really know what he's talking about.....mainly for the reasons I said above....plus the compression thing......unless you have a pressure sensor......you can't directly measure compression. You may be able to calculate estimated pressures by looking at exhaust temps.....but even then, not a lot of cars have EGT sensors.

BTW.....the ECU's on our cars are not under the passenger foot rest.

They are up under the dash on the driver's side. left of the steering column. I was in there this past weekend......trust me....it's a bitch to get to.

Here's a pic that may help.

[boostjunkie]

Hehe, I wasn't the one who knew the mechanic with the "false" info

At any rate, Adam told me that since I'm running much higher boost that I might try the colder plug. I'm not sure about the specs between stock range and the ones I have, but I'll try to pick up the info off the web.

Other thing with the temps is that you've maxed out your injectors hence causin your lean case.

That's what I was thinking, which prompted me to look into that injector duty cycle gauge. I'll see what I can come up with . . .

Thanks for your help!!

[Legacy777]

Do you have a multi-meter?

A med/good model should have a hz/duty cycle option on it. Mine does....just haven't played with it yet

[IggDawg]

I get hesitation if my boost is too high at part throttle. You have a MBC, so I bet that's what it is. Since there's no throttle position sensing capability, you're getting the evil full-boost-part-throttle thing. you're running leaner than normal, and with the throttle plate blocking the full boost (which really needs WOT) you're getting high intake temps due to inefficiency. I bet your EGTs are also higher than normal. I dunno if you have a EGT sensor? anyways, I think this is your problem. most people with MBCs have it. basically, you can be at 0-20% or 80-100% throttle. is this kinda what your'e experiencing? I got rid of my boost controler for the time being because of the reduced drivability. it was driving me crazy.

-IggDawg

[boostjunkie]

Nope, no access to a medical grade volt meter

[boostjunkie]

IggDawg, the only problem is that the hesitation is present at WOT (I make sure I don't boost AT ALL when not WOT). I can't explain it. If you got any other ideas, I'd be glad to hear them.

I went to autozone and picked up some fuel injector cleaner (maybe they're a little clogged - 177,000 miles - just maybe) to see if that would help. Plus, I'm stopping by Extreme Motorsports this afternoon to pick up that injector duty cycle monitor.

I also got a pretty good deal on a S-AFC which should be getting to me in a week or two, so I'm guessing the tuning/dyno work at TurboXS will be sometime in Feb.

Maybe then I can get some answers with some of their scan tools.