ggcnash Posted April 19, 2015 Share Posted April 19, 2015 Hi guys to make a long story short my 4.0 in the mj was on its last leg and on top of that the donor aw4 that I put in during my swap was really coughing up some heavy chunks of metal, so on to the present my buddy had a 91 engine complete that had a rebuild from a "trusted" engine builder about a year ago sitting on his shop floor with a 96 aw4 and 231 Bolted to it never installed! He was gonna put it in his xj but never got around to doing it so I bought it when I say never installed I mean never has been turned over straight from engine builder and bolting the trans and tcase is far as he got! So I started this swap last week engine really looked great. First problem alternator pulley was froze fixed that. Moving on bought and installed new distributor,complete cap and rotor, new plugs and wires, TPS, IAC, CPS, O2, and NSS. So on to the problem couldn't get this thing to crank has good fuel pressure and has spark with a spark tester (although I thought it looked weak) first thing I done was double check TDC and Reindex my distributor now I've read different things about this and people say it should actually be rite past #1 at TDC so this is where I first indexed it, I also refreshed the grounds again? Still nothing so my dad shows up he is confident its out of time so we go through the process again TDC and Reindex he wants it to be directly on #1 but he actually gets it at the leading edge. We try again it fires! Running like crap and backfiring all over the place. So first thing he thinks 180' out first we swap wires 180' nothing, so then we went 180' with distributor nothing. So then we take the new CPS off and put the old one from my original engine on nothing change but now we got a CPS code so we went back to the new one no code but still same results both CPS check out we also tried original distributor and cap same results but this time it was indexed directly on #1 cylinder nothing? Pls help gotta get the Manche running already got to borrow a car tomorrow to go to work Link to comment Share on other sites More sharing options...
ggcnash Posted April 19, 2015 Author Share Posted April 19, 2015 And guys when I say it was back firing and running like crap were talking it out a dent in my muffler! Link to comment Share on other sites More sharing options...
ggcnash Posted April 19, 2015 Author Share Posted April 19, 2015 ^Out =blew^ Link to comment Share on other sites More sharing options...
ggcnash Posted April 19, 2015 Author Share Posted April 19, 2015 Also replaced the ASD relay with AC still no change? Link to comment Share on other sites More sharing options...
1987Comanche Posted April 19, 2015 Share Posted April 19, 2015 How did you set the static timing before dropping in the dizzy? Might be worth an old school check. Pull the #1 plug, turn the engine over by hand, put thumb over #1 hole, and feel for air puffing out. Bring to TDC using this method and you know 100% you are on TDC for #1. My renix behaved exactly as described when I put in hecho en Mexico reman engine #1. Timing was way out. I fixed that and the thing proceeded to eat it's cam bearings. Dang ATK reman engine... Link to comment Share on other sites More sharing options...
Eagle Posted April 19, 2015 Share Posted April 19, 2015 I think you indexed the distributor wrong. Spark timing should be set to fire before top dead center. Since the distributor on the 4.0L is not adjustable I don't even know if the timing spec is published, but with the engine at TDC (on the compression stroke) the blade on the rotor should be at or past the turret on the cap. Link to comment Share on other sites More sharing options...
Jeep Driver Posted April 20, 2015 Share Posted April 20, 2015 The trailing edge of the rotor should be just leaving #1 when at TDC. Sounds like you may be a tooth off. Link to comment Share on other sites More sharing options...
ggcnash Posted April 20, 2015 Author Share Posted April 20, 2015 Well I pulled dizzy and plug #1 as described again and went through TDC process as described went a step further and pulled the valve cover just to make sure and both valves relaxed at TDC the rotor pointing to 5:30 no start Link to comment Share on other sites More sharing options...
ggcnash Posted April 20, 2015 Author Share Posted April 20, 2015 This is with the old dizzy put new one in same thing Link to comment Share on other sites More sharing options...
ggcnash Posted April 20, 2015 Author Share Posted April 20, 2015 I'm lost and frustrated so I put it away this evening spent all weekend trying to get this to fire keep the ideas coming please I'll be back at it tomorrow Link to comment Share on other sites More sharing options...
ggcnash Posted April 20, 2015 Author Share Posted April 20, 2015 Gonna buy some new plugs tomorrow these look fouled now that I been dumping gas with no start thinking of getting new CPS and distributor? Dunno just lost gotta get this thing going? Link to comment Share on other sites More sharing options...
ggcnash Posted April 20, 2015 Author Share Posted April 20, 2015 The trailing edge of the rotor should be just leaving #1 when at TDC. Sounds like you may be a tooth off. Got it there still no start? Link to comment Share on other sites More sharing options...
Jeep Driver Posted April 20, 2015 Share Posted April 20, 2015 Wrong flex plate. Link to comment Share on other sites More sharing options...
ggcnash Posted April 20, 2015 Author Share Posted April 20, 2015 Wrong flex plate.91 flex plate thought of that too, also thought about orientation but read somewhere if it's on its rite because it will only bolt up 1 way? Link to comment Share on other sites More sharing options...
ggcnash Posted April 20, 2015 Author Share Posted April 20, 2015 Wrong flex plate.Is there any way to check this with the inspection plate pulled like a part# stamped or something, like I said he had a 91 rebuilt with original flexplate don't think he would have put another or even had one but I shouldn't assume so if there is a way let me know if I gotta drop the trans I will. Thanks Link to comment Share on other sites More sharing options...
Jeep Driver Posted April 20, 2015 Share Posted April 20, 2015 You state in your OP that he had a 96 AW4 attached to the engine.........I'll be you anything that the flex plate is a 96 and not a 91. Link to comment Share on other sites More sharing options...
Strokermjcomanche Posted April 20, 2015 Share Posted April 20, 2015 Was there a difference in the 91 to 96 flex plates? I thought the renix and HO are different . Link to comment Share on other sites More sharing options...
ggcnash Posted April 20, 2015 Author Share Posted April 20, 2015 You state in your OP that he had a 96 AW4 attached to the engine.........I'll be you anything that the flex plate is a 96 and not a 91.this is possible but he doesn't have another flex plate he said the trams just had converter on it when he got it I've been drilling him all weekend on the phone! Is there a way to check it without dropping trans? Also to strokers question is there a difference in 91 to 96 if he happened to do that? Link to comment Share on other sites More sharing options...
HOrnbrod Posted April 20, 2015 Share Posted April 20, 2015 91-95 (OBD1) flex plates are compatible, 96 (OBD2) was different. The 96 flex plate won't play with the OBD1 ECU. But if it's firing up and running, rough as it is, I think you have a timing problem. Are all your sensors from the old 91 OBD1 engine? BTW, have you checked for fault codes using the ignition key sequence? Link to comment Share on other sites More sharing options...
ggcnash Posted April 20, 2015 Author Share Posted April 20, 2015 91-95 (OBD1) flex plates are compatible, 96 (OBD2) was different. The 96 flex plate won't play with the OBD1 ECU. But if it's firing up and running, rough as it is, I think you have a timing problem. Are all your sensors from the old 91 OBD1 engine?All sensors are new for a 91, except map it is from my original 91 it's on order though. Link to comment Share on other sites More sharing options...
ggcnash Posted April 20, 2015 Author Share Posted April 20, 2015 And to the codes yes sir I did never got any abnormal codes (except ac, it's unplugged) until I thought cps so I put my original from my engine in place of the new one it the threw an 11 CPS don't know if it's just because I unplugged it but there was still no change? Link to comment Share on other sites More sharing options...
ggcnash Posted April 20, 2015 Author Share Posted April 20, 2015 Sorry tapatalk doesn't wanna load fast enough Link to comment Share on other sites More sharing options...
ggcnash Posted April 20, 2015 Author Share Posted April 20, 2015 Also has new ignition MSD I picked up cheap from jegs. Link to comment Share on other sites More sharing options...
HOrnbrod Posted April 20, 2015 Share Posted April 20, 2015 And to the codes yes sir I did never got any abnormal codes (except ac, it's unplugged) until I thought cps so I put my original from my engine in place of the new one it the threw an 11 CPS don't know if it's just because I unplugged it but there was still no change? Changing the CPS should not throw a code 11. Never has for me. Check for the 5V reference signal (w. IGN ON) on pin 3 of the CPS connector near the fuel rail. Use pin 2 for your meter ground. Link to comment Share on other sites More sharing options...
HOrnbrod Posted April 20, 2015 Share Posted April 20, 2015 Also has new ignition MSD I picked up cheap from jegs. I saw it on the firewall. Was this on your old 91 when running? If not, bypass it if you can easily. Link to comment Share on other sites More sharing options...
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