Jenvey Heritage EFI

[TurboRagtop]

Greg, nice to follow along on your EFI journey, you are doing great.
One thing you will be pleased to know is that the longevity of your engine while running EFI will be significantly improved vs. running carbs.
I worked at Ford (1985-1995) when every engine they made was transitioned from carburetor to EFI. Even hard-core engine professionals never saw this coming: suddenly on every new EFI engine, the warranty claims for upper cylinder lubrication issues (cylinder wear, ring pack wear, piston slap, skirt wear, you name it) drastically dropped to near zero. At first nobody understood why, then they linked it statistically to the change from carb-fueled to EFI fueling. It makes that much difference, not dumping raw (liquid) fuel into the upper cylinder!

[msampsel]

Very impressed, seeing these transitions from the Dellortos you have been so fond of, to EFI.
Thing I dislike most about my Datsun is the emission smell. Did you consider adding a Cat too?

It looks like a tremendous amount of work, and it payed off.

[Gregs672000]

Thank You! It has been quite a journey but it is working pretty darn good. I had the motor out for several months but I've finally been able to do some tuning and clearing some gremlins, and understanding the system, the data I can capture and what it means (that's still ongoing for sure!). I just made some timing adjustments now that the compression ratio is more reasonable and that has really increased torque, and I'm learning how to tweak the fuel map and enrichment systems to avoid lean spikes or over fueling. Autotune doesn't do it all, that's for sure! Power is up everywhere, fuel economy is up slightly. On a recent trip around Mt Rainier that included some significant warp speed blasts at times it got 26.5mpg vs 25.5 previously, and that was before the ignition timing changes. I'm finding cruising loads and rpms from the data logs and will see what i can do to improve economy in those areas by leaning mixtures and advancing timing some more, but thats really secondary to good, safe and consistently powerful operation. I did notice and appreciate that the engine performance didnt change with altitude changes in the mountains now that it can compensate as it didn't bog or hesitate at the top of the mountain pass if I hit it. I have been battling a mysterious injector issue in #4 (lean) that I thought was wiring but now may be some contamination, but I had the same problem in #2 as well and it cleared... maybe #4 too as it has felt smoother since running some injector cleaner the past two days, but I haven't checked the plugs yet.
I recently redid the rubber mounts for the external tank for the fuel pump and that helped quiet it up a lot, but I noticed it was a little loud with the hot temps the past few days... it definitely doesn't like warm fuel. I still need to get together with uncle Pat to see if we can muzzle it some. Sometimes you can barely hear it...
So ya, pretty cool stuff

[Gregs672000]

Despite the fact that the car is more powerful than ever, I still have a significant problem in #4... this plug is way too lean. #2 plug was similar before but now appears nearly the same as the other two. #2 and #4 share common wiring as do #1 and #3, so at first I thought it was a wiring issue. Now I think it's an injector issue, possibly contamination from the install, but I'm testing the theory by swapping wiring and running new plugs. If it's wiring it will show now on 1 and 3; if its an injector in #4 it should read lean again. I need to put 50 or so miles on it to get some deposits to form before I will know. Unfortunately the injectors are not easily assessable by the customer per Jenvey, so I don't know yet how I will see about testing or clearing it, but I will! Zoom in: That plug is ugly and getting worse. The car would still blast to well over 100mph no problem. The orange color is from the Boostaine, which really helps to show how different they are. I look forward to fixing this problem!

[Daryl Smith]

Greg,
Is it just me or is that a coating on those plugs?
The 4th plug being a totally different colour would be concerning...grey, but, still coated? It's like it is getting a different fuel.....No idea what would cause that, oil getting into that cylinder?
I would guess you are still running rich....What AFR are you running at?

You are getting decent milage, near the same as I have been the last few tanks, but, I'm running with a bigger gallon (imperial measure) so you are doing better than mine so far on a bigger engine....My plugs come out almost clean, just a bit of a pinkish colour to them.

Injector pairing for wiring should be the same as the spark plugs, 1 & 4 and 2 & 3...Although I'm not sure it really makes a difference for the injectors...maybe...the computer changes fueling by the millisecond, so, it could make a difference.

[Gregs672000]

Yes, the orange is the Boostaine, and it really shows the difference. I think the plug is over heating due to a lean mix and thats the color and blistering you're seeing. I've researched cleaning injectors and despite what Jenvey said it does not look like there's anything complicated with accessing the injectors. Still investigating...

[twistin]

#4 plug looks like coolant
Check diesel injector repair shops they should be able to help.

[2mAn]

Greg, I love this. Keep it up.

If it was easy everyone would do it

[Gregs672000]

#4 plug looks like coolant
Check diesel injector repair shops they should be able to help.

I appreciate the input. I have not smelled any coolant burning nor lost any, but I'm open to the possibility that there could be something mechanical going on. All typical tests show no issues. I do have numerous pics of the plugs over time that do show a problem in #2 as well that has cleared. Especially in the first pics I took you can really see it was white but again I smelled nothing so I hope you're wrong! That is an angle I had not considered, so again thank you. Testing continues when the weather/family visit permits.

Thanks for the encouragement Simon, and it's always good to hear from you!

[Gregs672000]

Original pic, then after #2 cleared. What looks black on #4 is actually whitish overall. I've looked at this plug closely and it appears to be blistering some from what I assume is increased heat. I will check into coolant more closely however. I have since replaced all plugs with new but need to run it for some time. I swapped wiring and tested #4 injector and it appeared to work fine... we'll see!

[Gregs672000]

Update... swapped wiring, installed new plugs, cleaned injector #4 (at home with a pulse tester and pressurized carb cleaner... not easy but confirmed the injector appeared to spray well). First pic is after 35 miles, second after 135 miles... #4 continues to have problems, but #2 (while greatly improved from the earliest pics if you go back and look) also shows differences, except that it appears slightly richer than the others. This eliminates a wiring issue and suggests the problem remains with the injector OR with something else in #4 especially. I smell no coolant burning and mechanical testing (compression and leak down) has found no differences between cylinders. The final test will be to swap injectors between 3 and 4. If the problem remains in 4 then it's mechanical or an intake leak of some kind. I'm hoping that what I have is contamination from the install that went to injectors 4 and 2. They are first in line to the initial fuel feed through the new lines and internal fuel rail, with #4 being THE first in line for all and maybe the reason why it's the worst. Unfortunately I don't have a local injector testing place anymore, but will also consider taking them somewhere to be tested for flow. Any observations or thoughts welcome!

[msampsel]

Why not just drive it for 1000 miles or so? Seems it was driving fine right?

Wonder about temperature difference at various head locations? Can an IR thermometer detect any difference? You claim it dose not like hot fuel.

Just some rambling thoughts

Might try a different temp range plug in #4, see if it makes a difference?

[Gregs672000]

Thought I'd do a quick, rambling update... I've learned a lot, mainly that it helps to have an unbroken engine to tune on. Mine was broken, more than I knew. To summarize, broken top compression ring in #4 (only the plug showed it, no other testing), worn out intake guides and valve stems (oil contamination) and a leaking head gasket (coolant contamination). Now that it's back together and properly done this time (I hope!) and along with a drop in compression to somewhere between 10.5-11.0, it's finally starting to be consistent with the values used to inject the correct amount of fuel. Makes sense, as the sensors are well, sensing correctly now! Without good data, it is difficult to really tune things...it will run, and quite well even, but not consistently without requiring autotune to be constantly adjusting it. Autotune is a nice tool, but it's not perfect, and it's not meant to be used all the time. In addition, it is very important to have really good electrical connections and proper grounds as is strongly advised, done as they tell you. Our Datsun's are often rusty or with less than optimal connections and that can factor in.

With tuning there's a learning curve of course as you work to understand how the changes made show up on the graphs etc you're seeing and working with, but it starts to make sense and you learn how to "sample" the car or the tune. Right now I'm focused on making sure I don't see any air/fuel ratios leaner than 15 cruising or under light load, and getting rid of lean spikes with acceleration. I've also adjusted the ignition timing map to pull out a bit more timing under higher load at lower (2500) rpms as I heard some ping if I got on it. So cool that I can do that with a few taps on the keyboard on the side of the road.

Some other things I learned is that you need to be careful using some aftermarket parts... fuel pump for example (buy a REAL Bosche). She limped home one day after a long drive earlier this year, 200 yards at a time on a bad pump... no pressure, no go! I also added an inline fuel cooler on the return line and that has helped the pump stay quiet, so I don't need any sound deadening on the swirl tank. Also, it's a good idea to clear your braided fuel lines when you make them/the system before you run fuel to your injectors. All my injectors were spraying different amounts probably from the dust from cutting the lines and making them, not horrible but enough that the tech had to clear and test them all.

Anyway, I'm extremely happy with how it's running, the power, increased torque and top end. The car has never idled so well despite the cam, and the whole engine is much smoother. A big bonus is the increase in fuel economy. One 195 mile trip last weekend returned 32mpg... I didn't believe it and figured that the gas nozzle had just shut off prematurely, but yesterday's 167 mile trip returned 29mpg with a number of warp speed blasts, so that's very encouraging. It was mostly highway driving but still better than the 24-25 I used to get on trips. I have not made any attempt to tune it for fuel economy and have it set to target a 14.2 A/F ratio or 13.5 under heavier load, so in the future that may get even better.

Next up is a trip to the dyno. I want to have them finalize the timing map and make sure this engine is SAFE. My ears can't hear knock like they used to, and longevity is more important to me than max power now. If it's good and things are safe, I'll do a WOT pull as a final comparison on the torque band and peak power vs carbs.

[2mAn]

Congrats on the progress Greg! So happy to hear that its moving in the right direction. People generally assume the conversion to EFI is for more power, but for me its about that midrange, that cruising where a carbureted car simply cant match EFI and you're seeing that now.

Please take a video when it goes to the dyno for that one full throttle run.

Excited for you

[Gregs672000]

Today I decided to pull the plugs and see how things are burning now that the the motor is fixed. I have the fuel ratio set for a richer mix right now (often in the 13's), just to protect the engine some before the timing map is finalized, so I'm not concerned about the darker plugs. They are all burning equal now, no more injector unbalance etc. Did a cold compression test: 10 cranks, clutch in, throttles open. Pretty healthy (205-210)... you can see why I want to finalize the timing map on the dyno... no detonation allowed! I should be on the rollers within the next month, and this time I'll be sure to video document it. Close, soooo close. Pic is always upside down, right side up when selected.