rayven14 Posted September 23, 2012 Report Share Posted September 23, 2012 Well since we all like OIC's lets start with that: heres my lil crown jewel. Here is a pic of her heart, ... that Im ready to remove and replace!!!! Ok so heres the problem: So, I got a New Timing chain and associated hardware, got my lil bunny ears at 11 and 2, got the oiler at 11:28, dropped the Distributor in and its point Ohhh bout 1-130 ish. I drop the distributor in and set it dead center of the adjustment screws, reach for the key, she fires right up and purrs like a lil baby kitten. I mean it literally sounds sweet!!! Problem is it wont rev past 3 grand without boggin down and loosing power. sounds like the vacuum advance is all screwed up or something. Valve clearance is set at .25 across the board. Its a rebuilt head, fuel injected (obviously) new fuel pump, new fuel regulator. If I retard the timing its runs about 1500 rpm and is a bit more responsive at the throttle, if/when I advance the timing it returns to about 800 RPM and once again purrs like that kitten I was talkin about earlier. Could a vacuum leak cause this? Ive sealed every thing really well so I doubt there is a leak. What about the MAF or the TPS? Id hate to go run off and spend that kind of money and have it not be the culprit. Any advice? Quote Link to comment
rayven14 Posted September 23, 2012 Author Report Share Posted September 23, 2012 The 5th and sixth pic are incorrect, they were taken before I pulled the valve cover and turned the motor to tdc. The oiler is in fact at 11:28 Quote Link to comment
Dat Lurka Posted September 23, 2012 Report Share Posted September 23, 2012 Sounds like EFI Quote Link to comment
Sealik Posted September 23, 2012 Report Share Posted September 23, 2012 What about the MAF or the TPS? Id hate to go run off and spend that kind of money and have it not be the culprit. Any advice? MAF...?....you mean the air flow meter What did the TPS and and AFM come off of.......? You can eliminate those 'culprits' with some resistance tests. Also...you could slap a vacuum gauge on the engine Quote Link to comment
datzenmike Posted September 23, 2012 Report Share Posted September 23, 2012 Vacuum advance is highest at idle and light throttle. It becomes less and less as the throttle is opened. If at 3K full throttle there will be virtually no vacuum advance present. Where are you getting the vacuum for the advance anyway?? If it fires up that well you must be close to perfect. Your timing is about 12 degrees???? You have an E12-80 matchbox on it? I would have to say EFI for now. Quote Link to comment
rayven14 Posted September 23, 2012 Author Report Share Posted September 23, 2012 MAF = Mass air flow meter The whole system came from a 1980 nissan 200sx Ok so what are these resistance test you speak of Mr Sealik? Ok, help me out here, Im a novice mechanic,.. what would the vaccum gauge/test tell me? Hmmmm, perhaps that Im not getting enough vacuum for the throttle advance ... HMMMMMM Quote Link to comment
rayven14 Posted September 23, 2012 Author Report Share Posted September 23, 2012 Datzenmike... say it isnt so!!!!!!! Ok so worse case scenario its EFI.... so now what? I have another ECU I can plug in. Again Im a pretty novice mechanic but this system seems pretty... Well, Simple. Hell my dumb ass figured it out. Quote Link to comment
Dat Lurka Posted September 23, 2012 Report Share Posted September 23, 2012 Try that! Quote Link to comment
Sealik Posted September 23, 2012 Report Share Posted September 23, 2012 MAFs came out later.... Your early AFM has a flap in it....(vane style).....certain positions will read a different amount of resistance....same as the TPS You need the Haynes 200sx 80-83 book....has all the tests in it Quote Link to comment
rayven14 Posted September 23, 2012 Author Report Share Posted September 23, 2012 See I told you I was a novice mechanic.. I dont even know the difference. Quote Link to comment
datzenmike Posted September 23, 2012 Report Share Posted September 23, 2012 Make sure the 'flap door' is free to move all the way. Maybe the carbon track is worn... Quote Link to comment
Sealik Posted September 23, 2012 Report Share Posted September 23, 2012 See I told you I was a novice mechanic.. Either am I........buy that book..........read up. I would start at the TPS....confirm it's wired and working correctly.....then proceed eliminating the other components Quote Link to comment
rayven14 Posted September 23, 2012 Author Report Share Posted September 23, 2012 DatszenMike... Nice find! Sealik, ... well there are only two possible culprits: The TPS or the AFM. That or Ive got a big a$$ air leak somewhere. I dont think the warm up regualtor will have that big of an affect. Quote Link to comment
Sealik Posted September 23, 2012 Report Share Posted September 23, 2012 Yes....the air reg/choke has 'no' effect unplugged....coolant/head temp is another story I made a new wipe pattern a few years back....just shifted the elec board Can see it here.....sort of Quote Link to comment
rayven14 Posted September 23, 2012 Author Report Share Posted September 23, 2012 Hmmmm I see what appears to be several tracks, looks like 4? which makes sense if that little arm has two "wipers" So when you say you shifted the board did you simply unscrew it, shift it down or up and tighten it down? is this the 200sx AFM? Just ordered a new TPS, $37bucks, not bad for peace of mind, hopefully its not bad out the box. Beck Arnley is usually pretty good. Quote Link to comment
Sealik Posted September 23, 2012 Report Share Posted September 23, 2012 Yes...... 4 tracks Board was shifted toward the arm....creates a larger area for the arm to sweep across ...................the board. Loosen the 3-4 screws holding it......see if it can be shifted It doesn't take much and pattern cannot run off any 'edge'. Might have to augment holes. 37 bucks??? I would of bought the Haynes and a multimeter 1 Quote Link to comment
datzenmike Posted September 23, 2012 Report Share Posted September 23, 2012 DatszenMike... Nice find! Sealik, ... well there are only two possible culprits: The TPS or the AFM. That or Ive got a big a$$ air leak somewhere. I dont think the warm up regualtor will have that big of an affect. A leak that big would not allow it to idle. Quote Link to comment
rayven14 Posted September 23, 2012 Author Report Share Posted September 23, 2012 LOL Well I have a multimeter just gotta get the Haynes. Well honestly I elected to go with a new one only because the first one I had looked like it was in perfect condition (junk yard pocket item) I hooked it up and NO BUENO! so I used the original one that came with the system (it has a hole in the side of it and very speculative at this point) so for the $37 bucks, I figure hell at least I can eliminate that as a possible problem. Do I need to adjust the dual wiper arm at all, like make it so its tighter against the board? I adjusted the range of the wiper by loosening the screws, moved the board down a bit and screwed it all back together. Quote Link to comment
Sealik Posted September 23, 2012 Report Share Posted September 23, 2012 That AFM looks clean ....................................................................... ...."Do I need to adjust the dual wiper arm at all, like make it so its tighter against the board?"..... No...leave it the way it is. I would position the AFM horizontal while tuning though Quote Link to comment
bananahamuck Posted September 23, 2012 Report Share Posted September 23, 2012 Sounds like you just changed the timing chain?? And I noticed you have a pressure regulator , could you have bumped it or dropped it somehow .. does it read correctly ?? Maybe it`s just starving for gas. Totally guessing (edit) ,,,the EFI system you have on that car is beautiful piece of machinery .. :blush: Quote Link to comment
rayven14 Posted September 23, 2012 Author Report Share Posted September 23, 2012 I did do a timing chain, thought that may have been the culprit. I was wrong!, but at least now I can scratch another item off my checklist. OMG I took that piecs of crap FPR off, it was screwing up fuel pumps, two to be exact. I had the factory FPR laying around and so far its working like a charm and it made the pump alot quieter... so far its working well, at least at idle. Wont know for sure until I can get all the other gremlins worked out. Quote Link to comment
bananahamuck Posted September 23, 2012 Report Share Posted September 23, 2012 I see,,, so the not reving over 3000 was going on before the chain,, hence you did the chain,, well that throws my idea out the window.. The fuel injection on our 83 zx has tormented me on many occasions,, sometimes i think i have just miracled it into working. Quote Link to comment
rayven14 Posted September 23, 2012 Author Report Share Posted September 23, 2012 Yes, thought the darn thing skipped a tooth or something ... anything. So I decided to do the chain, it looked fine and everything lined up but since I had it apart... Quote Link to comment
wayno Posted September 23, 2012 Report Share Posted September 23, 2012 This is one beautiful engine bay!!! :thumbup: Quote Link to comment
doomdatsun Posted September 23, 2012 Report Share Posted September 23, 2012 I'd say AFM or vaccum leak, did you say that valve clearance were the same on all valves ? it should be for cold 0.008 intake and 0.010 ex, bad clearance will not let the engine do the correct breathing and combustion correctly so check that first don't assume that since its a rebuilt head that everything fine. since you installed a new chain did you make sure it matched the marks on sprocket and the crank Quote Link to comment
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