idosubaru Posted August 29, 2008 Share Posted August 29, 2008 1987.5 XT MPFI (non turbo) timing is 20 degrees, no check engine light occasionally the engine will not produce any power, like the fuel is being cut. goes from driving to nothing - just coasting. i can make it happen more by flooring it = %100 throttle, it'll happen more often. the exhaust is really loud (needs doughnut gasket), so it's easy to tell. as soon as it happens the exhaust goes from loud to non-existent, so the engine is obviously not doing anything. i guess it's either not getting fuel or spark? as soon as it "cuts out", if i ease up on the throttle a bit it will correct itself? could the FPR cause this? fuel pump shouldn't....that should either work or not right? Quote Link to comment Share on other sites More sharing options...
McDave Posted August 29, 2008 Share Posted August 29, 2008 It certainly sounds like a fuel volume problem. Is this the car that had a stopped up screen filter at the pump inlet? Quote Link to comment Share on other sites More sharing options...
suberdave Posted August 29, 2008 Share Posted August 29, 2008 EA82 looses all power did they ever have any power? just kidding, if it only dose it when you open the throtle plates 100%, check your TPS for a flat spot. also check fuel pressure. put a gauge on it and drive it with it taped to the windsheld. this way you can see if you are loosing pressure under WOT. i have replaced many fuel pumps (on nonSubarus) that had plenty of pressure at low RPM's but did non pump enough volume at higher RPM's or under load. also make sure you dont have a dirty air filter, or a dirty MAF. if you suspect a bad MAF, (i think 87.5 is hot wire) get some MAF cleaner and clean it out. just a few thoughts. -=Suberdave=- http://www.suberdave.com Quote Link to comment Share on other sites More sharing options...
idosubaru Posted August 29, 2008 Author Share Posted August 29, 2008 i knew someone was going to mention the "EA82" being the problem! thanks for the tips. i just drove it again. it's not just at full throttle and doesn't get better necessarily if i let off the pedal. same car that had bad fuel and a non working fuel pump, i put another one in. it'll do it any time...at take off or at highway speeds. it'll be very rythmic sometimes...accelerate for 2 seconds, decelearate 2 seconds (no power, no exhaust sound), accel 2 second, decel 2 seconds... no particular RPM, speed or gear. it's obviously much more noticeable on inclines but that might not mean much. Quote Link to comment Share on other sites More sharing options...
idosubaru Posted August 29, 2008 Author Share Posted August 29, 2008 New fuel pump - same thing. I'm going to try and look into the FPR next....as soon as I find one. Quote Link to comment Share on other sites More sharing options...
torxxx Posted August 29, 2008 Share Posted August 29, 2008 disty could be failing. my 86 did the same thing and I tried everything except disty, finally did it car drove for 100k more miles how you are saying it cuts on wide open and then starts to correct itself when you let back off. this is the same thing mine did. I'm not positive thats whats wrong with urs but worth a shot. Disty may be hard to find because its gotta be off a MPFI non turbo. and IIRC its gotta be 1985/1986. I paid 75 bucks for it Quote Link to comment Share on other sites More sharing options...
idosubaru Posted August 29, 2008 Author Share Posted August 29, 2008 Disty may be hard to find because its gotta be off a MPFI non turbo. and IIRC its gotta be 1985/1986. I paid 75 bucks for it mine's a 87.5 so you're dead on. it's got to be a very specific one for sure. good point, probably not a bad idea to just have one on hand anyway since i don't have any. Quote Link to comment Share on other sites More sharing options...
NorthWet Posted September 1, 2008 Share Posted September 1, 2008 It's gotta be asked... how are the plugs, wires, rotor and cap? I have had also sorts of bad behavior out of marginal wires. Quote Link to comment Share on other sites More sharing options...
idosubaru Posted September 1, 2008 Author Share Posted September 1, 2008 shouldn't be those, i think i replaced them. but i honestly don't know so i probably should give it a whirl. actually i might have a minute to go buy those parts now before we leave! Quote Link to comment Share on other sites More sharing options...
idosubaru Posted September 2, 2008 Author Share Posted September 2, 2008 swapped MAF and coil, no change. I bought a new cap and ordered the rotor today, so i'll find out soon if that's any help. The points in the cap are definitely warn, but i have no idea if it's "too much" just by looking. At idle the spark appeared to be fine, i could see it in broad day light and it would jump a good 4+ inches....any more than that and it *jumped* through me! Quote Link to comment Share on other sites More sharing options...
idosubaru Posted September 4, 2008 Author Share Posted September 4, 2008 update on this 1987.5 XT (non turbo) manual trans that cuts out. I've replaced/checked these items with no change: Wires, cap and rotor, plugs are fine Ignition coil TPS MAF Unplugged O2 sensor Distributor Fuel pump Intake hose is fine Timing belts and timing are golden No check engine light I guess the ECU i got from a subaru store in Colorado could be bad, but i doubt it. Quote Link to comment Share on other sites More sharing options...
robm Posted September 4, 2008 Share Posted September 4, 2008 Fuel filter? It wasn't on your list... Quote Link to comment Share on other sites More sharing options...
idosubaru Posted September 4, 2008 Author Share Posted September 4, 2008 Fuel filter? It wasn't on your list... thanks rob - i installed a new fuel filter as well. Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted September 5, 2008 Share Posted September 5, 2008 Timing belts and timing are golden Did you replace them or just check that they are there? I ask because I had a hesitation problem on an SPFI motor that was due to loose belts. I tried everything under the sun and it never got fixed till one day the passenger side belt broke and after I replaced them it runs like a new engine. It's starting to sound like this could be a wiring issue. With the XT's having the ECU in the trunk you may be running into the "corroded-wireing-under-the-carpet" bug that some folks have seen. With all the time you have already invested it might be wise to just lay eyes on every inch of sensor/ECU harness - especially those parts that are under carpet or door sill plastic. The only thing I can think of that would cause your complete power loss and not set off a code at the ECU would be complete power loss to the ECU itself. I would consider running some LED's off the power supply pins of the ECU itself and put them where you can see them just to verify that you aren't losing power to the ECU and thus shutting down the injectors, coil, or fuel pump. GD Quote Link to comment Share on other sites More sharing options...
idosubaru Posted September 5, 2008 Author Share Posted September 5, 2008 GD, i can double check the belts, but fairly certain i replaced them. it seems to be too predictable and idles perfectly, i wouldn't think a wiring issue would do that. but i will check under the p/s seat. my mind is cloudy by now but it did seem to get worse over the past couple weeks driving it and back then it seemed to be worse when the car was warmed up, which could point to wiring. the distributor wire has been spliced together, and there's that shielded wiring all sprawled out over the place. one of the wires must be that two part kind...internal wire with strands of silver wire encircling it. i guess the external shielding wire was pushed out of the way. i'm going to get a new one, but i doubt that's causing it. Quote Link to comment Share on other sites More sharing options...
idosubaru Posted September 5, 2008 Author Share Posted September 5, 2008 update for forgetting two things (thanks to members asking): Wires, cap and rotor, plugs are fine New fuel filter Ignition coil TPS MAF Unplugged O2 sensor Runs the same with knock sensor unplugged Distributor Fuel pump Intake hose is fine Timing belts and timing are golden No check engine light Quote Link to comment Share on other sites More sharing options...
McDave Posted September 5, 2008 Share Posted September 5, 2008 the distributor wire has been spliced together, and there's that shielded wiring all sprawled out over the place. one of the wires must be that two part kind...internal wire with strands of silver wire encircling it. i guess the external shielding wire was pushed out of the way. i'm going to get a new one, but i doubt that's causing it. Well, shielded wires are shielded for a purpose. And improperly spliced shielded wires are easily shorted... Quote Link to comment Share on other sites More sharing options...
ple1ades Posted September 27, 2008 Share Posted September 27, 2008 I am having a very simular problem with my 87 RX but only over 5k rpms at wot when I back off the throttle it stops very strange I am thinking TPS but dont know. Quote Link to comment Share on other sites More sharing options...
rpholz Posted March 1, 2009 Share Posted March 1, 2009 ahh! it just stops. lol i am having the exact same issue with my 86 xt mpfi non turbo and am looking for an answer with minimal amount of spending. Quote Link to comment Share on other sites More sharing options...
Gloyale Posted March 1, 2009 Share Posted March 1, 2009 mine's a 87.5 so you're dead on. it's got to be a very specific one for sure. good point, probably not a bad idea to just have one on hand anyway since i don't have any. Should be able to use any disty from 88+ MPFI or even SPFI disty. There MAY be 2 pins to swap in the SPFI to use it for MPFI, I don't remember excactly, but they are all the same CAS style disty Only the early Flapper Style MAF systems had a different disty. Quote Link to comment Share on other sites More sharing options...
akc Posted March 2, 2009 Share Posted March 2, 2009 Mine was doing the same thing we tried the same thing after several days of tinkering we checked the fusable links and all the fuses for conections when we were done it worked fine. apparently one of them was not in all the way or?? the other thing that I have found on mine is it only runs good on premium gas it sputters and is underpowered on regular (fuel additive works good too) we also thoughly cleaned the carb. (it was not getting enough gas) Quote Link to comment Share on other sites More sharing options...
rpholz Posted March 2, 2009 Share Posted March 2, 2009 well problem fixed, at least on my xt, replaced the pcv spark plugs and coil, didnt do anything then i noticed the fuel pump was really freaking loud all of the time inside and out of the car so i broke down and finally spent the hundred bucks on a new one and runs like a top..... FINALY!! Quote Link to comment Share on other sites More sharing options...
RMVR53 Posted March 2, 2009 Share Posted March 2, 2009 Gary, did you fix yours? Mine is also an 87.5 XT and doing the exact same thing with one addition...the tach/timing starts to jump right as it starts to die. Mine is also a warmed-up thing. Runs great till it warms up then, my guess anyway, is that when it switches from open loop to closed loop it starts this crap. And yes, the distributor for the 87.5 is specific to the XT/non turbo ONLY. No other Ru used this unit. I finally found one at a Suby dealer - how 'bout $528 for a new distributor!!! seems the module is not available separately for this car/dizzy like it is for all other models. I installed a dizzy out of an 88 and the car runs like crap (warm or cold). Anyone know what we have to do to change dizzy to newer to go back to an earlier unit (all the way bacxk to points if I have to!!) Bill F Quote Link to comment Share on other sites More sharing options...
twhb Posted March 5, 2009 Share Posted March 5, 2009 disty could be failing. my 86 did the same thing and I tried everything except disty, finally did it car drove for 100k more miles how you are saying it cuts on wide open and then starts to correct itself when you let back off. this is the same thing mine did. I'm not positive thats whats wrong with urs but worth a shot. Disty may be hard to find because its gotta be off a MPFI non turbo. and IIRC its gotta be 1985/1986. I paid 75 bucks for it I am thinking that jargon is hard to figure out. Would a "disty" be a distributor? My EA-82T cuts out when I push the acclerator hard toward the floor and then it starts running ok when I back off. If I ease up on the accelarator the engine runs up to higher rpms. Any thoughts? Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.