May 1, 200817 yr im kicking myself for even asking this, but until i can get a carb'd setup im kind of stuck. my 89 gl 1.8 spfi non turbo 5 spd 4x4 on demand wagon runs good, but up until 3k rpms, if i try and run it hard at all it jerks, now a hard jerk or anything, like it gains & loses power as it climbs in rpms & then once it gets to 3k it runs like a champ. my check engine light isnt on and i know its not my clutch slipping, so what could this be? also it gets better if i run her kinda hard for a while, but its really bad for the first good while after i start driving it. its driving me nuts because the 4x4 works great but i have to rev and dump it or it wont do crap. thanks! Jon
May 1, 200817 yr Have you Checked the Timing? ... That Behaviour was done once in my White Wagon, due to Timing; I just Adjusted it More Advanced, doing the "Drive Test" ... Adjusting it and Driving, then Adjusting and Driving, Untill it Reaches the Optimum Performance. I have mine at 25º. Also it can be a Clogged Fuel Filter / Air Filter, Electrical Failure and Vacuum Leakage. I Suggest to Verify all those Parts. Good Luck!
May 1, 200817 yr air filter, fuel filter, PCV are all good maintenance items anyway if they've never been replaced. any basic history of this car....miles, any recent tune ups at all? there's a ton of things actually that could cause this, not necessarily intake related. how old is the timing belt? Usually you would get a Check Engine light if a sensor signal is causing issues. But not always. Do you know if the Check Engine Light works, does it come on when you first turn the ignition on? FPR - fuel pressure regulator. it's in line with the fuel supply and should have a vaccum hose on it, not sure how the SPFI is set up. pull the vacuum to the FPR, if it's wet inside of it then the FPR is ruptured, just replace it. check all of your sensor connections - corroded harness connectors are VERY common. the CTS (coolant temperature sensor) is a good one to check. TPS and MAF are possibilities but based on your description i would rule out the things mentioned above.
May 1, 200817 yr Check for loose or removed vacuum. I'd stay away from putting a carb on it. I had this problem with a turbo ea82...It did it with a different intake and turbo on it. My friends and I think it was a ring or head problem. How's your spray pattern look on the injector? Run some cleaner through your system then replace the fuel filter. I agree with above, do a tune up, check timing. Replace the replacable to reduce the variables.
May 1, 200817 yr Adjusting the timing is done by rotating the distributor either clockwise or counterclockwise. I would pull and check all your spark plugs. If you do not know the last time they have been changed, then I would change them. Even if they look good, they could be faulty. You'd be suprised how many times Ive solved this kind of problem with new plugs. That, or the coil is on its last leg. No real way to test the coil. They could work great at low RPM however at a higher RPM the system can become weak and cause a misfire which would result in your poor performance past 3k. Both are cheap repairs. -Brian
May 2, 200817 yr Author someone has misunderstood me-i get GOOD performance past 3000 rpms-but BAD in my low end. and it was running on 3 cylinders before i changed the plugs and distributer cap and now its running on all 4 but it feels like one or 2 of them is missing ever so slightly, what do i have to do to rotate the dizzy-take the cap off and rotate it or ??? also-ive been wanting to clean the injector but i have no idea where the injector is located as there is 50 freaking hoses running to my tb.
May 2, 200817 yr Author how do i go about checking for leaks, i havent messed with vac lines much more than plugging them off or running new ones...
May 2, 200817 yr The dist. is clamped with 2 bolts - you'll see them just below the outside bottom edge of the cap, opposite each other. Loosen them and rotate the complete dist. But if you don't have a timing light you won't know what's happening. Also, I believe you need to connect the diagnostic plugs to lock out the computer advance and aim for 20 degrees advance. On my Loyale, these are the 2 green plugs flapping (disconnected) in the breeze near the brake booster. When you're done, disconnect them again - they are supposed to be that way. Check the previously mentioned possibilities for vacuum leaks as well. Spray some WD40 at all the vac. line connections you suspect (one line at a time)- if the revs change you've found a leak.
May 2, 200817 yr You shouldn't be plugging vacuum lines unless you know what they do. Checking for leaks involves spraying something flammable (brake cleaner, carb cleaner - any fast evaporating degreaser really) aroung the engine bay at various "suspect" areas and listening to the sound of the engine. A smoothing of the idle or an increase in the idle speed indicates a leak of some kind. Spray some down the throat of the MAF (avoiding the hot/sensor wires) and listen to the change in pitch - that will give you an idea of what you are looking for. Beyond that, you should run a D-Check of the SPFI. It has the capability to self-diagnose many simple sensor problems. Do a search for D-Check or read the partial FSM linked on my SPFI conversion page for a full description: http://home.comcast.net/~trilinear/EA81_SPFI.html GD
May 2, 200817 yr Author i owned a turbo dsm that i plugged off the egr & much of the emissions vac lines because they were unneccesary, and i will take this stuff into advisement tomorrow, for now, im hittin the sack.
May 2, 200817 yr "You shouldn't be plugging vacuum lines unless you know what they do." Roger that - I opened a huge can of worms a few years ago when I rebuilt the carb on my 84, and had not mapped out the lines prior to disassembly. What a PITA to sort out afterwards. Also, don't get scared of the smpi - I think it's actually more user-friendly than my 84 Hitachi carbed unit, after doing the research here.
May 2, 200817 yr Author how is that a horrible vehicle? it was a very fun ride that looked nice and had tons of aftermarket parts produced for it, dohc and 16 valves, a lot more technically advanced than my current vehicle considering a difference of only 2 years. granted the damned thing needed worked on all the time... lol
May 2, 200817 yr DSM's are junk. The ECU's last 5 years at most due to leaky caps, the engine's are prone to a host of failures, and the overal quality of the cars was very poor. They sold on looks and performance alone - how many older Mitsi's are still on the road? When was the last time you saw any 80's one's around? Oh yeah - they crushed them all. And I hate everything that's transverse. It's a general policy of mine. You'll find lots of folks like me around here. Been there, done that, got the t-shirt, ect. GD
May 2, 200817 yr You'll find lots of folks like me around here. I wouldn't go that far... there aren't many like GD around. However, you cant treat your Subaru like you did your DSM. They are 2 completely different vehicles, with completely different technology. In order to locate a vacuum leak, spray around your engine in spots with carburator cleaner. Do this with the engine running at idle, while warmed up to operational temp's. If you spray somewhere, and the engine idle smooths out or picks up, there is a vacuum leak in that area and deserves some further investigation. Ripping out emissions stuff and plugging off vacuum lines will NOT fix your problems, it will only cause more. -Brian
May 2, 200817 yr DSM's are junk. ... What Car is That? ... I don`t Know what means DSM`s... ...And I hate everything that's transverse. ... Well... I Don`t Like Traverse Engined Cars too. If the Failure is at Low RPM`s, it sounds to me like a Vacuum Leak... Good Luck!
May 2, 200817 yr Author when someone talks about a dsm, they typically are talking about a 90's mitsubishi eclipse-eagle talon-or plymouth laser, all of which are pretty much the exact same car, but with small changes in appearence and rebadging, and some very small changes in the actual mechanics (very small changes). i had one and it was a fun car, gas mileage wasnt great and it needed worked on all the time, but there are all kinds of aftermarket parts made for them and they are nice looking cars.
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