prezucha Posted June 24, 2015 Share Posted June 24, 2015 Hi all, first posting.. I have a '72 Z which we just did an l28 carbed swap. The engine ran very nicely with straight header. Messed with timing a bit and forgot to set back to sweet spot. Got gas in the morning and took car down to muffler guy to fab an 8" pipe with flange to mate header with exhaust system. The car ran OK down to shop. When I went to pick up car in the afternoon the car would barely run. Sounded like it was running on 2 cylinders. Bought new fuel filter. Dropped the exhaust at flange thinking an animal crawled in exhaust pipe and was blocking it. Nothing. Removed plugs and 1 and 6 were dry, others wet. Towed car home. Removed wires from 2,3,4,5 and car ran exactly as when they were attached. Car was running on only 1 and 6. To make a long story a bit shorter, today I took my distributor, cap, wires, and coil from my sweet running '70Z and installed in '72. Oh, both are running the '79 ZX distributor with E12-80 module. Car didn't run. Could barely keep car running on 1 or 2 cylinders. I was kind of hoping it would still only run on 1 and 6 kind of proving the distributor was acting up... So, my question is, any ideas? Could the muffler guy have over revved the engine and done harm? I did do a compression test and they were 160,162, 168,169, 162, 160. Not bad. Just realized 1 and 6 are lowest compression and those are the cylinders that are firing.... Strange. Bad gas? Why would it fire on 2 cylinders? Removed valve cover, and at TDC the cam gear mark was -v right where I think it should be. Don't think the chain jumped a gear... Anyone ever hear these symptoms before? Any thoughts would be appreciated! Thanks in advance. Paul Quote Link to comment Share on other sites More sharing options...
seattlejester Posted June 24, 2015 Share Posted June 24, 2015 Welcome to hybridz. 1 and 6 are at TDC at the same time, that would be a lot of time in-between ignition events. Hoping for it to run on just those two cylinders is a bit of a long shot. That's less then a 3% difference in compression. I don't think it is the compression, if there was no compression that would be a problem, but those are fairly good compression numbers. Do you have a spark tester? Can you test individual spark plugs to make sure the plugs aren't firing? You've done a good job in describing the problem and such, we just need a bit more info. Voltage readings would be helpful, the spark test results would be helpful. In addition to the cam gear having the notch at TDC, are the cam lobes on cylinder number 1 in the bunny ear position? Is the distributor just passing by cylinder 1? It seems strange that it ran down and no longer runs, that points towards an electrical problem, or a sudden fuel problem. All the electrics work fine? If they did a poor job grounding the work piece it could have burnt up a ground by chance. You said some of the spark plugs were wet, are we talking soaking wet or moist? What carb did you put on the car? What fuel pump are you running? Do you have fuel pressure? Quote Link to comment Share on other sites More sharing options...
prezucha Posted June 24, 2015 Author Share Posted June 24, 2015 (edited) Hi Seattle Jester, Thanks so much for your response! At midnight! To answer your questions... Running on 2 cylinders wouldn't get me down to the corner store Or even the mechanic one block away! I thought compression numbers were within 5%. 3 is even better! I will pick up a spark tester today. I removed 2 through 5 and car ran the same so I kind of assumed they weren't firing at all. I know, I know, don't assume. 2 through 5 I would say are moist, not soaking wet. I can barely keep car running now but playing with timing might help. When I say running I am talking barely!! What voltage readings would be helpful? I put distributor, coil, cap, and wires back on my '70. But yesterday I got 11.7 at coil + and - with key on. I will put everything back today and get more voltage readings... I've TDC'ed the car many ways. Feeling pressure in #1, lobes as bunny ears, rotor pointing at about 9:00, etc. Played with distributor so that it's just passing #1 plug. Remember none of this was touched at muffler shop. He simply welded in an 8" pipe to a flange and welded that pipe to existing. Could he have joy rided the car and done something? All electrics seem fine (not clock ). I did put 5 gallons new gas on an almost empty tank... Do you mean that he may not have grounded properly when welding? Do these cars have a ground chassis to engine? My old Sprite did but this doesn't seem to. Fuel pump is mechanical and fuel pours out of hose to carbs when disconnected! Oh, one strange thing is I sprayed starter fluid into both carbs and it didn't do anything! Even the rough idle on 2 cylinders went down! Normally the revs should spike, right? The engine came with a points dizzy but car wouldn't fire. Took the distributor from the engine we removed, a D6K8 with E12-80 module and it fired up instantly! Since the problem occurred I installed the dizzy from my 70, an D6K9 with E12-80 with magnet from the other distributor. This set up works on my car perfectly! I did have a loose ground on coil not allowing my car to start for a day until I found it. Thanks Seattle Jester! I am hoping for an easy fix. My son hasn't driven the car yet with the new engine and he is dying to! Would a loose ground somehow only affect 4 cylinders and not all 6? Cheers! Getting a spark tester now... Paul Edited June 24, 2015 by prezucha Quote Link to comment Share on other sites More sharing options...
Xander Posted June 24, 2015 Share Posted June 24, 2015 Did you replace the ignition leads? I once had the same problem. running on only cylinder 1 and 6. The leads go on counter clockwise. not clockwise. that solved the problem for me . Quote Link to comment Share on other sites More sharing options...
prezucha Posted June 24, 2015 Author Share Posted June 24, 2015 Seattle Jester, Sorry, just reread your posting and you asked what carb... I read "what distributor". The carbs are the Hitachi stock carbs. Looks like 70-71 according to ZTherapy they have the unique heat shield with the "U" shaped cutout and plastic oil filler caps. Just bought the spark plug tester and here are results. Strange. Cylinders 1 and 6,which are currently firing and running the car poorly, have weak spark. All 2,3,4,5 have slightly stronger spark to the tester! Plugs 2-5 are wet! I just took spark plug from 1 and installed in 2 and visa versa. Car started but still the same. NOW, I removed spark plug 2 wire and it ran worse! Replaced. I removed spark plug wire 1 and it ran back on 2 cylinders! Possibly 4 bad spark plugs? How could that be? I bought new ones and will install and report back. Very strange indeed! Later... Quote Link to comment Share on other sites More sharing options...
prezucha Posted June 24, 2015 Author Share Posted June 24, 2015 Hi Xander, I checked and double checked. The L28 engine has same firing order as 240, correct. I just took off distributor, cap, and wires from my 240 (running great) and put on new engine. Does not run. Will change spark plugs and see. Here's a crazy thought. Cylinders 2-5 have slightly higher compression. Could muffler guy have revved the engine high enough to do damage to those 4 plugs? Never heard of this. Will change and report back... Thanks! Quote Link to comment Share on other sites More sharing options...
NewZed Posted June 24, 2015 Share Posted June 24, 2015 Sounds like it's flooded, and the plugs are fouled. Remove all of the plugs, clean them up (or replace with new) and let the cylinders dry out. Don't make it complicated. It ran before, you have spark, wet plugs show that there's fuel. Assuming the "wet" is fuel and not coolant. Shops have been known to hoon a customer's car. Is the wetness fuel, for sure? Quote Link to comment Share on other sites More sharing options...
prezucha Posted June 24, 2015 Author Share Posted June 24, 2015 Ok, Seattlejester and Xander, Someone has some 'splaning to do'. I put in new good spark plugs and it fired up right away! Plenty of smoke coming out but that cleared up. I bring a decently running car in to have a header to muffler flange installed and after he does the work the car is running on 2 cylinders! Now the timing was a bit off bringing it to him as I was messing with it a little but it ran "ok" there. Could he have revved it and somehow damaged the plugs in 2-5 because the timing was a bit off? Plugs physically look ok... Car now does run good. No test drive yet but it revs nicely. I feel like I need to advance the timing a bit more but I ran out of play even after allowing most play moving the plate... I appreciate all your comments and please feel free to comment and speculate. I have fixing something without really knowing what happened! I know the plugs made the car fun but why were others bad? Cheers! Paul Quote Link to comment Share on other sites More sharing options...
prezucha Posted June 24, 2015 Author Share Posted June 24, 2015 Hi NewZed, Sorry just saw your post after posting. Yes, new plugs did it. But why? Hoon? I can guess what that means... Compression is good all across. First thing I checked! If bad, I would go after the guy to have engine repaired... Thanks! Paul Quote Link to comment Share on other sites More sharing options...
seattlejester Posted June 24, 2015 Share Posted June 24, 2015 You have a great attitude and understanding of how to relay the problem, kudos sir. Glad you got the problem solved. No worries, I was unfortunately still at work . There is a ground strap from the engine to the chassis (close to the battery), if the welder was poorly grounded while welding it could have sent some current somewhere where it wasn't supposed to. Kind of a long stretch and that is an assumption if the shop is reputable. I doubt he smashed the plugs by reving the motor, either would have had to skip a few teeth or one of the pistons let go. That would be very easily identifiable. If you want to check for sure, burn the old spark plugs with a torch to clear the carbon off and put them back in and try running the car, if it runs well then the spark plugs were just fouled really badly, this is one of those picture is worth a thousand words situation. I was aiming towards the motor being flooded a bit assuming your voltage readings during cranking were fine. Seems like Newzed hit it on the mark. The hitachi carbs can have the floats sink, the open cylinder would have had the fuel evaporate and possibly fire, but the closed ones could have had excess fuel and the first ignition event fouled the plugs causing a weak spark to be unable to light the fuel mixture. Are the carbs rebuilt? Maybe time to adjust and inspect the floats. Spraying starter fluid doesn't do much on the hitachi carbs as the opening is real small and you would have to lift the pistons and open the throttle plate. Remember starter fluid supplies fuel, but without air the engine can't use the extra fuel so it wouldn't rev any higher without more air being added into the mix. Quote Link to comment Share on other sites More sharing options...
prezucha Posted June 25, 2015 Author Share Posted June 25, 2015 Hi Seattlejester, Thanks and I appreciate your comments. I've read many poor problem descriptions and forum member responses. I tried to explain best I could but being tired and rushed can sometimes not have good outcomes. I'm glad you could assess my problem with the info provided. I will try cleaning the plugs as you suggest and test them. A good idea! I guess I didn't say what happened next... Bought a new aluminum radiator and after a quick test drive water was skirting all over. Radiator has a hole in the bottom! This is the next problem to solve. My son thinks the car drives great though! Very smooth compared to the old engine! I will now install the new magnet in the original distributor when it arrives and get back in the car. Once that is in, with new plugs and wires (I ruined two wires with all the changes I was doing) I will have a local shop sync the carbs and time it properly. Again, thanks you and all for your suggestions and support! Cheers! Paul Quote Link to comment Share on other sites More sharing options...
Tony D Posted June 27, 2015 Share Posted June 27, 2015 I was going to say "wet plugs" - change the set. If the floats weren't set right or stuck, or the starter ststem was on and you flooded...this can happen. On EFI cars it floods from extended cranking and the cold start valve over fueling....or the Coolant Temp Sensor coming unhooked... Quote Link to comment Share on other sites More sharing options...
TimZ Posted June 27, 2015 Share Posted June 27, 2015 (edited) I was going to say "wet plugs" - change the set. If the floats weren't set right or stuck, or the starter ststem was on and you flooded...this can happen. On EFI cars it floods from extended cranking and the cold start valve over fueling....or the Coolant Temp Sensor coming unhooked... Yep - this can happen pretty easily. So yes it's possible that this could have happened at the muffler shop, but if it did it was likely due to simply flooding the engine on startup, not hooning. Also, fouled plugs happen when carbon deposits form on the center electrode's insulator, essentially grounding it out and making it impossible for it to create a spark. These deposits are pretty stubborn, and carb cleaner or brake cleaner won't touch them. The only thing I've found to be effective is to burn the deposits off with a propane torch - you have to hold the flame on the electrode area until it glows red and looks white again all the way around the center electrode. Edited June 27, 2015 by TimZ Quote Link to comment Share on other sites More sharing options...
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