AFR readings???

[argniest]

On a 1978 280z

can anyone tell me what typical/normal readings from an AFR meter like the innovate LM-1 should be reading at idle, normal driving and under heavier accelaration?

[ozconnection]

You have to understand that all engines are built differently and as a consequence, have different dietry needs. To give you 'random' figures as to what will right as opposed to what isn't is risky at best. If I said wide open power AFR should be 13.2:1 and you ran that on a 15psi boosted turbo engine with cast pistons, you'll be looking for me in a real hurry....

Firstly, you need to give us a detailed account of your engine. What mods? How does the car feel in its current tune? Are you looking for max power or best economy?

Ok, on my L28 with stock cam and head, stock compression auto trans, 800 rpm idle, Holley 4 barrel, Arizona 4 barrel dual plane manifold, headers and a 2.5 inch exhaust, MSD 6 and a 280 zx dizzy running 22 static and 34 total without vac advance, I run:

12.8 at idle (to keep the idle strong when the revs drop on selecting drive, in fact I tune my idle in drive for this reason) and when I use the power steer and the A/C is on. Idle vac is 16 inches in gear, 18 in neutral and AFR falls to 11.9-12.2.

Plugs have a nice light grey colour too.

See what I mean!!!!

Cruise is around 14.5 and

WOT I like to see 12.8-13.2

I use Aussie premium unleaded with a octane rating of 98. No pinging is detected.

I use a 180 degree thermostat, water wetter, distilled water an LD28 water pump and a 20 psi radiator cap. All this to make sure no pinging...at all. A large electric thermo fan keeps temps in check.

Do some driving around if you can. Adjust things, get out there and feel what its like to drive. Look at your innovate and get a feel for what 14.5 is like for example. Adjust a bit leaner and how does it run? Does it surge or hesitate? Soon you'll get a feel and you'll know when its feeling strong.

Depends on how anal you are to get it right. I spent heaps of time on it and was able to get things to the point where I was rejetting etc for the seasons! To me, that's where I wanted to be..as good as or better than a factory calibrated car. It can be done.

Good luck mate

[argniest]

You asked for it, you got it. Here is what I can tell you about my car.

I have a 1978 280Z car, stock everything. I am not a mechanic just so you know. Am anxious and willing to learn everything that I can to work on my Z baby. I am reading the EFI bible and FSM as much as I can to learn about things. I just want to car to run safely. Dont need it to be extra fast or extra economy. Just to run close to specs and also without the darn smell that I have to endure right now.

The car drives OK. But I feel it has definately more power to give. And other mechanics are telling me that too. Two separate mechanics have looked at car and worked on it for me, and driven it. Here are some facts about....let the book begin

I always use premium 93 octone BP gas (non ethynol)

After we had new plugs and oil and tweaked the AFM, I was able to lay some rubber on the pavement. Before that, I really dont think it had nearly enough ooomph to even do that. Unless you reallllllllly tried hard, I suppose then you could have. But it felt like a real dog at first.

0. The #6,5,4 plugs seem to get really fouled up (they are black and kind of wet looking, especially #6) even after 75 to 100 mile drive on new plugs, and #3,2,1 look powder grey or brown (and both mechanics said that #3,2,1 were burning pretty normally)

1. fuel injectors are old and should be replaced. I think number 6 fuel injector may not even be working correctly according to one mechanic. He said after 30 seconds of driving in 1st and 2nd gear, that we were only driving on 5 cylinders. This is my relative who has been working on imports since the 70's. And also he said because of that, it wont be getting as good as gas mileage of course.

2. all electrical connections that make sense, need to be cleaned, and grounds need to be cleaned. I am doing that now.

3. I feel that once that happens, it is going to change how the car runs (better or worse dont know)

4. The old JECS air flow meter has both screws turned all the way down. I didnt do that, that is how the car was. Here is the article http://atlanticz.ca/zclub/techtips/afm/index.html

5. I have a new AFM, but when I put it on there and drove a little bit, it ran like crap. I realize the AFM is complicated (for me anyway) and lots of tweaking that can be done (based on an article someone on here told me about). So for now, I have the old one on there.

6.It burns about 3/4 of a quart of oil in 1000 miles. Because I drove it that far over the summer....for better or worse. I base that on the fact I drove about 1000 miles in the summer, and it used about 3/4 from H to L mark on the dipstick.

7. Did compression tests on it and leak down tests. Basically the mechanic who did those told me my rings/seals are bad (or at least getting bad) and therefore wanted to rebuild/refresh the engine. The psi for compression was 125 in 4 cylinders and 135 in two of them. None of them adjacent to each other. I dont remember exact results of leak down tests, except he said the car has piston ring issues that need to be replaced.

I read in the FSM, that the new compression was like 165-178 psi or so...going from memory those are the numbers I remember.

8. Got new water temp sensor in there. That helped it run a little better for sure.

9. When I drive it, the gas mileage averages 11 to 17 mpg. Its 11mpg when plugs are fouled up, and got about 17mpg when I had put in new plugs and new oil.

10. When I drive it, there is a big time smell surrounding the car. I dont know if its a gas smell or exhaust. but it sort of seems like a gas smell to me.

if windows are up, I dont smell anything. But if the windows are down, watch out. Youre eyes will be burning in about 5 minutes. This is a very big concern of mine. Does it mean its running too rich or too lean...I wish I really knew that for sure.

11. All spark plug wires are new/newer. They LOOK new to me anyway.

12. Not that this has anything to do with the engine but here goes: the transmission was rebuilt, the differential was rebuilt, The brakes re-done, all/most suspension issues have been replaced, all bushings, rubbers etc, has new shocks. The car does ride nicely as far as those things go. My relative did all this work for me. But then we have the engine issues that I am living with right now.

13. When I first start the car, and idle for like 1 minute...it seems to blow a little blue smoke or white smoke, but I cant tell which color it is for sure, but its blowing a little smoke at first. After you start driving, I never really see any other smoke. Even if I stomp on it. No smoke. It did this in the warmer weather/summer, so I know it wasnt just from freezing temps we have now outside. The thought is that the valve seats are bad or going bad, and some oil is getting down there overnight, and burning up the next time its started.

14. Per mechanics request, I used several cans of Sea Foam into the gas tank when I filled up. I do feel it helped give me a little more power. Also I used Star Tron from StarBrite. Another supposedly good fuel additive.

15. The engine always seems to start on the first try, and it idles around 800/900 rpm. However, it does feel to me, that its running kind of rough. I dont know if its missing, backfiring, etc. since I dont know enough about engines. However, I would just say it feels kind of rough. I can see the mirrors on the sides of the car vibrating when its idling. Maybe thats normal ??? I dont know. I never drove in a good running 1978 Z car before.

16. Something I wrote about in another post in this forum, was that on Jan 1st and 3rd this year, the car just died for no reason. Then it turned over, and turned over several times and it would not start. I waited 5 minutes or so, then it started first time. This REALLY scares me, because now its just become unsafe and not reliable and could get me killed because of that happening. I am cleaning all the connections and grounds wherever I can get to. Hopefully that will fix the problem. I dont know if that was because of a faulty fuel pump or electrical delivery problem to the fuel pump, or god knows what.

It was 5 to 10 degrees outside both times when that happened. I was driving 20-30 mph or so too, when it happened.

All the snow actually melted on our streets which doesnt always happen in the wintertime, then it rained, and I felt it was a good time to drive the car. And that is when it DIED ON ME!!! And remember, it never did this before in the summer or fall. Very depressing. But I am sure it can be fixed.

17. I think this might be related to #16, I felt the car lurch or hesitate for just a split second. And it did it a few times in a row, and then just kept driving along normally. So I thought anyway....And soon after that is when it died. One time it was like 1 minute or two minutes later after that hesitation that it died. This also happened on Jan 1st, 2nd, and 3rd when I was out driving it. I dont know what that hesitation was all about, but again, it NEVER did that in the summer or fall.

I am trying to find someone with a CO meter, just so I can get a baseline reading for future reference and comparison (I also read about a procedure is FSM on page ET-8 and ET-9 where its talking about having to enrichen the fuel mix when getting a CO reading....so I am not sure about if that applies to all Z cars or what????).

And I recently bought a Innovate AFR meter, so I will be able to take peroidic readings with that...as changes are made.

18. I believe the timing is currently set at specs....10 BTDC. A mechanic adjusted that, when he was playing around with the car one day. The same day he tweaked AFM, took compression readings etc. Although he may have slightly advanced or retarded it. I cant remember for sure. But I know it was fairly close to specs.

19. Valve clearances/valve lash??....Ok now this one is a little fuzzy to me, but the mechanic also pulled the head cover and checked the clearances on the valves. He was saying if they were too tight or loose it could cause problems. He measured them with a gapper tool, and said they seemed fine. And so, he ruled that out, as part of my engine running issues. He put valve cover back on after that and went on to check other stuff.

(while valve cover was off) he also checked the timing chain, and said it felt and looked fine to him. This guy worked on Z's for many years before...so I believe him.

20. ALso the exhaust manifold gasket was replaced. I guess the original one was all messed up and some bolts were not tight. But that was all fixed up.

21. Vaccum leaks? I have been told there are not any by a mechanic who checked it with a guage. I didnt see that test myself. I am going to get a guage and start learning how to check that myself. I have also been visually inspecting all hoses (top ...sides... bottom of each hose). I found one tonight that connected to the air regulator (about 5 or 6 inches long hose that had a crack about an inch long in it, but wasnt noticable, until i took the hose off, so I could clean the wire clip on the sensor underneath it. BUt besides that, I dont hear any hissing. And I also found a few things that were missing clamps and added those onto the hoses

22. Oh yeah, I also bought a good quality (that is all I buy) new alternator for the car. High output. Because I will be installing a loud stereo in it, at some point in the future, when all the running problems are behind me.

23. Front bearings were replaced on both sides of car. They were not in good shape.

24. Lastly, I have noticed since wintertime set in, that there are a few electrical problems that have appeared out of no where. NOne of this happened when it was warm. Back passenger side brake light doesnt always work, side marker lights in front dont work (they used to), one of the dash lights doesnt always work (the one on top of speedometer), the head lights dont always come on, but the bright lights always do....the hazard lights dont come on. And I believe there are a few disconnected wires, so the reverse lights dont work. I just havent had time to track that down all the way. But I did find some disconnected wires that I think have to do with the backup lights.

All other lights and guages seem to work all the time. And the horn did work too, although I havent beeped it lately

So with these kind of ghost electrical problems, I am cleaning all connections. I hope that helps to fix some of these problems I am currently having.

Can I get an award for the longest post on this forum???? or maybe a good slap in the face might help too

Edited January 18, 2011 by argniest

[ozconnection]

Wow, that's some response!!!

I appreciate that you're learning your way around your car at the moment and unfortunately you seem to have a lot on your plate with that machine.

I guess the best place to start...is over. I know you have mentioned that a mechanic has looked over your car and has given you the thumbs up. That's fine, but have you done the checks yourself? When you do, you'll learn more about your car everytime. A check by the mechanic doesn't teach you anything. Mechanics, like doctors, get it wrong sometimes.

Looking at a part and assuming they're right (like your leads) is wrong. Test them. All sorts of electrical mayhem can occur because you've got one faulty ignition lead. Learn how to test them. Google it if you have to. Your FSM might also give you the values you need.

YOU need to establish and continue a systematic checking procedure of all your systems. Get an exercise book and index it. Write dates down when parts are replaced. Take notes and even photograph it. Eventually, you'll build up such a vivid mental picture of the workings of your car, you'll be able to do anything just thinking about it. Experienced Z guys and girls will know what I'm talking about here.

Don't skimp. Don't assume. You'll never get it right if it's wrong and you thought it was right all along.

Beg borrow or steal the tools you need to get the job done. Join a local car club and pick the brains of locals who may have experienced similar difficulties. Borrow their tools. Post questions on forums.

I don't own a Z and my car isn't injected so I can't give you specifics about your car. Someone else might like to chime in here in that regard.

Cheers and good luck mate.

Edited January 17, 2011 by ozconnection

[argniest]

Yeah, but I type fast, so its not a big deal. I totally understand what you are saying. And that is why I am collecting tools, and slowly but surely going to learn how to test everything that I can do myself. I am cleaning things, taking things apart, putting/exchanging a few things on the car...etc

Its not that I dont believe them, but both the mechanics are running/owning very busy shops...and they of course cannot spend nearly the amount of time that I can ...to inspect things. I already know 5x more than I did before winter started about my Z baby. Because I have been on these forums, and reading over the FSM and EFI bible, etc...and been tinkering on the car for several months now.

PS

There are some pics I just added. I still have original tires and rims, but all the rims were a little bent, and all tires had flat spots. So needless to say when i got upto 55 to 70mph the steering wheel was shaking a lot. Also, I found out I had bad bearings in the front left side. So once the bearings were fixed, and the new Eagle GT tires and rims...it rides smooth. I like both the old rims and new rims though. But favor the new ones more.

Edited January 20, 2011 by argniest
I added a few pictures

[ZCurves]

argniest,

Reading your posts, you have my curiosity. Can you post some pictures of your Z? We all enjoy pictures of each others Z's and they help others in resolving problems.

Edited January 17, 2011 by ZCurves

[ZCurves]

Very Nice Z! What is the color code? I really like it. Mine is 510 Lt Met Blue.

[sblake01]

I always liked that color (510)

Edited January 18, 2011 by sblake01

[cozye]

Very nice

[argniest]

Its *supposed* to be 510 blue. But I bought a new air dam for it, and had the air dam painted 510 blue. Well guess what??? The car aint no 510 blue

Its a custom color that is darker than 510 blue. So at least I know that. Someday, once the engine is purring and I have taken car of some other comparably minor issues, I will plan on getting a new showroom paint job. My relative who restores car, also has state of the art painting shop. But one baby step at a time. Who knows how long this is going to take to get it running close to specs. If it will take a partial engine rebuild (like new rings, seals, etc) then that will really put a wrench in the works.

I got a lot of connections in the engine area, all pulled apart and cleaned up as of tonight. And all the grounds too in the engine area. That included cleaning the fuel injector connections. And in the process, I found a few clamps msising and one split hose on the input side of the air regulator. So I replaced that and put new clamps on it. So after all that I had to see if she still started up. Yup No problem.

I am going to clean a few connections inside the car that have been pointed out to me, as potential problems.

Oh yeah, I also got the fuse box cleaned up, and all new fuses put in there.

I will be on here asking for help once I am ready to remove/install the new ones. Just to see if there are any tricks tips or traps to look out for. Because, I have decided I will replace the fuel injectors myself. But the screws holding them in are really locked in there. I put a very little wd40 on one of them, and will get some of that other stuff (cant remember name) to unfreeze them I hope. I am going to be very very careful because I dont want to strip them. The screws seem like kind of soft metal. Not like some of the hardened ones on the car. So got to work on one at a time to get all the screws looose. Once that is done, then I can begin removing fuel rail, and then do the rest of the job. I am also going to buy a much larger screw driver so I can get some serious leverage on those screws. I have lots of big screw drivers now, but they wont fit the screws.

But first I am going to try to fix the light problems in the car. Side markers dont work and I know at least one of them or both did. The hazards dont come on. Sometimes the headlights come on and most the time they dont. Sometimes the passenger side brake lights comes on and sometimes not. So that is going to be a real challenge for me to try to read all the wiring diagrams and trace down the problems and FIX THEM!!!!! I hope! Oh man that could take me weeks or months to figure out. I have never done that before in a car. Oh boy....

I think all electrical type problems only showed up when it got cold here. In summer and fall I swear all this stuff worked. And I know it worked when I bought it 2 years ago. But anything can happen in 2 years, with all the work that has been done on it. So whooooooooooo knows.

In fact the headlights came on tonight after I hooked up the battery again before I started her up. But a little while after starting and stopping it. I decided to flick on the lights. NOPE, they didnt work. And I checked them a few other times this week. And they always worked. But before I idled it last time, they didnt work. And after warming it up, then they worked. This is NUTS! I know, seems stupid to keep testing it like that....but those are games I like to play with the car.

Edited January 20, 2011 by argniest

[FastWoman]

Be careful with those injector screws! A few of mine were frozen. The forward most one on the #1 WOULD NOT BUDGE, no matter what I tried on it, and it eventually broke off. I had to remove my intake manifold (which had to be done anyway, so no great loss) and take it to a machine shop to have that screw and a few other stubborn fasteners extracted. But be careful, because if you're not (and even maybe if you are), you'll end up with enough of your engine disassembled that it looks a bit scary.

PBlaster and Kroil are great products for freeing up frozen bolts/screws. You might also try a miniature torch on the injector screws. I sort of wish I had tried that.

You headlight issue might be a dirty/corroded switch -- assuming you've ruled out your connectors. You can open it up and clean it if you're careful. Don't bend the tabs too much. I've never done it, but I've been told...

[TomoHawk]

I replaced the injector screws with socket head screws so I could get them out easily if I need to.