rickyellow zee Posted July 28, 2012 Share Posted July 28, 2012 I have a 78 280z with a stock L28ET swap( stock injectors, fuel pump, etc) and have the timing set to 8 deg BTDC as per the shop who did the swap. I take their word as they are the premier Datsun shop in the area. I checked the FSM and it states the timing should be 24 deg BTDC for the turbo model. The shop says they set the timing that way to avoid pinging when I turn the boost up to 10 Lbs. I trust them but want to know.....What you guys have your timing set to for stock L28ET swaps like my own? Thanks. Rick Quote Link to comment Share on other sites More sharing options...
randy 77zt Posted July 28, 2012 Share Posted July 28, 2012 i did an 81 swap into my 77 and I ran 20btdc.the zxt ecm's dont have much of a timing curve built into them.factory spec was 20 for a 81.I ran 12-13 psi boost at road race tracks no problem.make sure you have new or flow tested injectors.a lean cylinder will preignite.when I installed my engine I used new injectors. Quote Link to comment Share on other sites More sharing options...
rickyellow zee Posted July 28, 2012 Author Share Posted July 28, 2012 THanks for the reply. Im gonna bring it back to the shop and get the timing set back to stock and see if things improve. The car made 110 lousy hp on the first pull on the dyno. I had my tuner friend Paul take a look at it and he said the air fuel ratio was super rich so he leaned it out by altering the AFM. WE did another pass and did 130whp. Still really low hp for 6 lbs. Im hoping turning the timing back to stock fixes things. Any thoughts? Quote Link to comment Share on other sites More sharing options...
dexter72 Posted July 28, 2012 Share Posted July 28, 2012 Why didn't your tuner friend just advance the timing while it was on the dyno?. If he adjusted the afm, he could have advanced the timing too. Quote Link to comment Share on other sites More sharing options...
rickyellow zee Posted July 28, 2012 Author Share Posted July 28, 2012 (edited) There was no room left to adjust the timing at the the distributor. I believe thats what he said. He was looking to get 18-20 deg but could not get it by adjusting the dizzy. He was talking about modifiying the disk in the dizzy that has the little whole drilled in it to get the desired timing. Anyhow.. So I called the shop that did the swap (differnt guy than tuner) and they said they would put the timing back to stock. They also said not to bother modifiying the distributor disk as it would make matters worse and that they had the ability to do timing correctly. Maybe its off a tooth somewhere? Dunno. Im gonna get them to do that and then bring it back to the dyno and see how we look. Ideas?? Edited July 28, 2012 by rickyellow zee Quote Link to comment Share on other sites More sharing options...
letitsnow Posted July 28, 2012 Share Posted July 28, 2012 I would bet it is off a tooth if you ran out of adjustment. Quote Link to comment Share on other sites More sharing options...
NewZed Posted July 28, 2012 Share Posted July 28, 2012 I would be nervous about the shop if they got the timing wrong the first time, on a stock engine. Are they the premier Datsun shop, like expert in old Nissans, or the premier Nissan shop, like don't know much about old Nissans. I would be nervous about the "tuner" guy. If he knew that you had a stock engine and you couldn't get the timing advanced, modifying the disc in the distributor is not the obvious first solution attempt. I would also be nervous about his AFM adjustments, also not the first thing to do for a rich mixture. If it's all stock - "stock L28ET swap( stock injectors, fuel pump, etc) - with a stock ECCS, there's really no tuning to do on a dyno either, as I understand the stock system. What non-stock part have you added that can be tuned? Quote Link to comment Share on other sites More sharing options...
rickyellow zee Posted July 28, 2012 Author Share Posted July 28, 2012 The shop that did the swap deals with z cars exclusivley, mainly old z cars. As for my tuner hes been tuning cars for decades and tuned my other car (Honda CRX, SOHC 1.6 11 lbs 235whp). He knows his ****. Hes not very familiar with Z cars but took a look and figured out the AFM and made the mix leaner in minutes. I trust him entirely. As for non stock parts an aftermarket FPR was added, thats it. It appears that the AFM was tampered with prior to the swap as one of the glue blobs were broken. I figured I would run it on the dyno to see if the afr was good and check the timing as well under load. Everything was off. Now its a matter of trying to fix things starting with the timing. What other way is there to alter AFR on these cars? I thought the AFM was the only way? Quote Link to comment Share on other sites More sharing options...
NewZed Posted July 28, 2012 Share Posted July 28, 2012 I was just pointing out some flaws in the picture. "He knows his ****. Hes not very familiar with Z cars" seems like a contradiction though. It looks like the shop and the tuner are learning on your engine. Reading the chapter in the FSM about the L28ET engine control system would have told them all about the timing and the other things that can cause a rich AFR. Is the aftermarket FPR adustable and is the fuel pressure set to the factory spec.? If they didn't know how to set timing, they probably are guessing high on the fuel pressure. Hondas probably run 45 psi or higher. If they couldn't get the timing to spec., there's no need to do more tuning, since the ECCS needs the right timing. It was off by 16 degrees. Another odd thing - "The shop says they set the timing that way to avoid pinging when I turn the boost up to 10 Lbs." Is the stock L28ET boost adjustable? How are you going to turn up the boost? Why is this experienced Z shop thinking this way? Anyway, good luck with it. I just hate to see a wallet being abused. Quote Link to comment Share on other sites More sharing options...
B. Whisky Posted July 28, 2012 Share Posted July 28, 2012 Maybe post the dyno results, hopefully more can be learned. Ignition timing makes quite the difference on the et', as static compression is way on the low side on these. Get that down first, then deal with the fuel mix. There are numerous tricks for tuning the eccs, but get the basics ironed out first. Make sure it reaches operating temp, all electrical and vacuum connections are solid, proper fuel pressure at idle, etc. Quote Link to comment Share on other sites More sharing options...
dexter72 Posted July 28, 2012 Share Posted July 28, 2012 The oil pump may be installed incorrectly and thats why the timing cannot be advanced. Have the shop that did the swap check for that. Quote Link to comment Share on other sites More sharing options...
rickyellow zee Posted July 28, 2012 Author Share Posted July 28, 2012 NEWZED, It has a manual boost controller to raise boost. Pretty simple actually. I have one in my CRX. Turn a knob and get more boost. Never heard of one? Google Turbosmart MBC. I'd have to go by the shop to get the dyno results, I may or I may not. Doesnt matter. Timing was off and that needs to be set, bring it back to the dyno and see what the results are. Fuel pressure is 30 psi so its correct. Im thinking the oil pump was installed incorrectly as well which would explain why timing could not be set correctly. Ive got 2 different shops working on the car so things can get confusing. Since I got the car back both shops have been in contact with eachother so we can get things right. Not worried. Thanks for all the replies. Keep ya posted. Rick Quote Link to comment Share on other sites More sharing options...
NewZed Posted July 28, 2012 Share Posted July 28, 2012 (edited) No need to get smart. Your first post says "stock" and describes a bunch of very basic mistakes from your professionals in getting a stock engine running. Your money... And 30 psi is not right. You can't fake this stuff. There's too much easy information out there. Edited July 28, 2012 by NewZed Quote Link to comment Share on other sites More sharing options...
cgsheen Posted July 28, 2012 Share Posted July 28, 2012 (edited) Extremely easy to check proper install of the oil pump shaft with the engine at TDC on the compression stroke. Just pop the distributor cap and check the rotor position. I hate to see people screwing with the AFM - it seems to always be the first thing noobs go to - when it should be the LAST... The pic you put up before - with the "broken glue blob" - was the blob on the wiper arm. The screw for the spring setting was intact (and should remain that way (or, possibly "should have")). I hope your tuner friend marked the original position... The L28ET ECCS is actually really easy to trouble shoot and the Factory Service Manual is fairly concise and easy to follow. It's a step-by-step guide. All the tests there should have been gone through first... Edited July 28, 2012 by cgsheen Quote Link to comment Share on other sites More sharing options...
rickyellow zee Posted July 28, 2012 Author Share Posted July 28, 2012 NewZed, not being smart, just sayin. It seems as YOUR the one being smart in some of your replies. Im no hater or smartass. Truce? Ill have to check the FSM to set ther right fuel pressure since its wrong. Thanks. Rick Quote Link to comment Share on other sites More sharing options...
FricFrac Posted August 6, 2012 Share Posted August 6, 2012 The stock EFI system is very crude. If you want to tune your car run and aftermarket ECU. It's a very worth while investment. Playing with the AFM is akin to bubble gum and twigs tuning. Are you running an intercooler or the stock J pipe? Are you running the '81 turbo CAS or the 82-83 optical dizzy? What year ECU? Do you have the stock base for your dizzy? There are a significant number of diffferent distributor based for the L series engines. Quote Link to comment Share on other sites More sharing options...
Pyro Posted August 6, 2012 Share Posted August 6, 2012 There are 2 bolts to adjust the timing. One on top and there is another on bottom that is hard to see that bolts the distributor to the adjustment plate. The bottom bolt also has adjustment. Quote Link to comment Share on other sites More sharing options...
rickyellow zee Posted August 7, 2012 Author Share Posted August 7, 2012 Im running no intercooler at the moment but plan on installing one. As for the ecu its from an 81,so is the afm. The dizzy is from an 83. I have since had the timing set to 20 deg btdc and had some success with getting some power to the wheels. So much in fact that i felt the clutch slip as i hit 4500 rpm. Now i need a new clutch. This car seems doomed. lol I have a prescision intercooler that came off of one of my other turbo cars that i plan on using once i get the clutch issue resolved. Quote Link to comment Share on other sites More sharing options...
softopz Posted September 6, 2012 Share Posted September 6, 2012 Hmmmm ecu from 81 was auto . The wiring is almost the same and uses a completely different type of ignition pick up hey bro not being an ass trust me and the other advice on here go with something more tunable you want reliability and better performance your not going to get that from a 30 year old ecu. So go aftermarket there's many choices or go with the z31 ecu it will probably be the cheapest and fastest conversion. You can also then add nistune and start the real tuning good luck. Quote Link to comment Share on other sites More sharing options...
HowlerMonkey Posted September 9, 2012 Share Posted September 9, 2012 The "pickups" send the same signalling to the ecu. The only difference you need to deal with in a 1981 vs 1982/83 system is that the 1981 system uses a dropping resistor while that dropping is done within the ecu on the 1982/83. As suggested above, try to set the indexing of the wiper arm back to stock. If you need to fiddle around, you can play around with spring tension (mark stock position) to get good running. If you have good running already but an idle issue, you might be able to smooth it by adjusting the screw for the air flow meter bypass port..................screwed in is richer and unscrewed is leaner. Try to start with a stock setting there as well. Now anything else wrong with the car can cause you to screw your adjustments up by compensating for the real issue which causes issues again once you discover and fix the failed part.....such as a stuck aux air regulator, vacuum control valve, cracked hoses on "modified F" shaped connector that mates a bunch of 1 inch diameter hoses together, or even a throttle body and tps that is adjusted improperly. Quote Link to comment Share on other sites More sharing options...
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