RMVR53

I'm so sick and tired of this.... In my on-going pursuit to find the cure for my firing problems, I have replaced half the car...ok that sounds stupid but heres where I'm at.... New: plugs, wires, cap, rotor, CAS (yes I finally bought one...and it didn't fix my problem which REALLY pisses me off) fuel and air filters (ok..I was throwing parts at it early on)... cleaning/etc: removed all ground wires and cleaned at contact; removed all connections/plugs and cleaned contacts (under the hood for both); heres where I'm at: once the car warms up, the tach will bounce wildly and 99.9% of the time while under load/acceleration will miss and literally quit. Get your foot out of the gas and tach comes back and miss-fire quits. Get it going fast enough when this happens and under deceleration everything is fine...its just under throttle. Can the TPS switch do this kind of electrical crap with the tach ? If that wasn't going on I'd be looking at the TPS for sure but right now I'm at a loss... as a precurser - this is all after a 10 month tinker rebuild to replace a cracked head...ran fine prior to teardown. thanks Bill

well, other than removing the existing pipe, cutting it back to where I can get into the cat and clean it, any other recomendations? (other than a custom made piece from a shop)

no spacers... my pipes bolt straight to the heads Bill

I need to "remove" the front cat on my 87 XT (non-turbo). Will an early car (say 82 GLF) fit? Need to keep the O2 but run just the mid-pipe cat Bill

June 87 build and no vacuum advance...and I tried to swap in a dist from an 88 and the plugs are different. I then swapped the plug from my 87 onto the 88 dist (same wire count and color) but it would not work. Went to my neighbor who had a 88, put the dist in his car and it ran fine...go figure...

you sure on the years?..I not doubting you G, just funny how the brain stayed the same but they used a handfull of distributors that aren't interchangeable!!

will a replacement have to come out of an 87 MPFI XT or what are my options? thanks Bill

I had a chance today to work on the XT again. Got it warmed up and when the crap started happening I stopped and removed the alt belt. Problem continued so that is ruled out but thanks for the idea. next thought anyone? Bill

question...how can the alternator cause the tach to jump wildly and at the same time the cause engine to try and die?

yeah I know...you'd think after all this time passed it would be fixed. But it ain't. I have narrowed things down a bit however. I borrowed a friends XT and we put my dizzy in his car. He drove on it for a month (it took that long to catch back up to him) so it ain't the dizzy. So now I'm lookng a open loop/closed loop issues. Car runs fine when cold, starts this miss/bouncing tach crap when warmed up. Runs fine if you keep the rpms below 1800, above 1800 and the above miss/bouncing tach problem rears its ugly head. I considered the TPS but can that really have an effect on the tach/firing? Same for the AFM... ideas gang? thanks Bill

yeah I know...you'd think after all this time passed it would be fixed. But it ain't. I have narrowed things down a bit however. I borrowed a friends XT and we put my dizzy in his car. He drove on it for a month (it took that long to catch back up to him) so it ain't the dizzy. So now I'm lookng a open loop/closed loop issues. Car runs fine when cold, starts this miss/bouncing tach crap when warmed up. Runs fine if you keep the rpms below 1800, above 1800 and the above miss/bouncing tach problem rears its ugly head. I considered the TPS but can that really have an effect on the tach/firing? Same for the AFM... ideas gang? thanks Bill

you mean as in output, short or ???

to answer your question .... no. I haven't found a CAS yet to my financial liking. I put another dizzy in the hole and I thought it was cured. Drove it local about 10 miles and had no porblems. My daughter shows up about 10 minutes later and heads off to town in it. She got to the end of the street and it started all over again....so at this point I really have my doubts about it being in the dizzy... Bill

supposed to be for 2 wheel

Thanks, thats kinda what I thought. My question arose from how they were sold. They were sold the 88's together and the 87's together. Thats what got me wondering if there was a difference other than left/right. When I get them put on I'll offer up the other set (unless I find another XT to put them on!!) Bill

I picked up 2 pair of struts on E bay a while back for my 87 XT. 2 pair with 2 different part numbers 1 number apart. Pretty sure they are made by Monroe. Would these be a left/right or anyone have an idea..or know what the actual PN's are.... on the boxes it says 81788 and 81787 ideas? Bill

The two big harness'/plugs I worked with were above the tranny - but in a plug clip of sorts. And yes I unplugged/cleaned/plugged those as well. Anything I moved or disconnected I cleaned....which in doing all this I did find a bad ground wire (chassis to Alt bracket) but installing a new wire did nothing for the condition...unless this wire being bad caused the CAS to go bad from bad/no ground. Bill

A late update but better than never..... Finally had time to do some diagnosic work (called cleaning every frikin contact on the engine). I was able to get the problem to surface in a controled manner...I think. When the engine warms up, if you keep the rpms under 2k you can control when/if it fails. Stable rpm's over 3k and you can "feel" it going south...engine starts to stumble/load up, then start to backfire etc. then die. BUT if you get out of the rpms (back under 2k) it will continue to run for about 5 minutes under 2k before that starts to load up. Now the not so funny part... Shut it off, restart it, and you can drive away...about 30 seconds later it starts to fail again. Shut it off, let it sit for about 2 minutes, and you can drive it for 5 minutes or so. So... I assume Im replacing the CAS at this point unless someone offers another solution... Bill

so if the short block is the only thing that I can use, I might as well work with whats sitting in the car so long as its not case related failure. Bill

no clue...the guy who has it just says the engine is shot so not sure what it needs. Since I can get the "L" motor for $150 I didn't figure it was worth messin with if it was a viable swap Bill

ok its not anywhere close to new but what the heck.... I'm looking at a 93 AWD Turbo Legacy sedan. Great shape but toasted engine. I found a Legacy L (non-turbo) wrecked but a good engine. Can I swap it out under the turbo stuff? Bill

I'll check it this afternoon. Thanks!!

but...will it effect the tach as well?

Unfortunately, I don't have another one to drop in. I was at the yard Tuesday and there were no new prospects to scavenge from. Is there another plug on or in the dizzy I am missing or is the optical unit a part of this total harness coming out of the head? Based on your (extensive) experience, I don't feel so bad right now...not that that helps the situation!!!

OK...so we will refer to it as a CAS instead of an IM...good to know the correct terminology!! I used contact cleaner on it to make everything as clean as I could prior to plugging it in. Is there a plug anywhere other than in the harness between the dizzy and sidewall (under coil area)? Dizzy was from same month GL. I had to make 3 different trips to the yard (over a 2 month period) to find this one with even the same plug on it. Just got lucky it was from the same month. I did try to swap in a later unit - made a harness adapter for it (4 wires were the same color from both units) - but must be different enough as it didn't work. any who... BTW..thanks for your responses Skip. You are quite knowledgeable!