I've spent the last few months building a 2056 from scratch and tonight the project finally came to the point where I could fire the beast up. Oil pressure came up pretty quickly (30 - 40 seconds). Once pressure had been established, I installed the spark plugs and fired the motor up. Once running, I had to pump the throttle keep the motor from quitting. Holding the throttle open at any one setting resulted in the motor stopping from what seemed to be fuel starvation.

- Timing: Set this on the fly and it didn't affect this particular aspect of the motor's running behavior

- Stock D-Jet

- Points and dwell: Running a new Pertronix unit

- Fuel pressure and pump: I don't know what the pressure numbers are, but the pump and regulator worked great two months ago on the old motor.

- ECU: Also worked great on the last motor

- Cam: Running a new Raby 9550

I'm pretty worn out, so it might be something more obvious that I'm missing. I should add that the engine sounds mechanically spot-on. Hooray!

Any help or troubleshooting ideas you're able to provide would be most welcome.

My complete progress thread can be viewed at
http://www.roadglue.com/forum/showthread.php?t=209

Thanks in advance!

Fuel lines hooked up correctly? Could be fuel pressure going in the wrong side of the regulator.

BTDT it's easy to do.

if its not a fuel line mixup...What MPS you running? A 037 will kinda work but a 043 runs like sh*t as its too lean but usally it will atleast idle.
Note: with that cam you must adjust the MPS to set the correct AFR.

Geoff, the 9550 is the stockish D-Jet compatible cam. He might be able to get away with boosting fuel pressure only. And maybe a TS2 resistor change.

Trigger points?

Great suggestions

- I'll double-check the fuel lines. It was late when I hooked the last bits of the lines up, so perhaps I did something wrong.

- I have a bunch of MPSs. Which one do you recommend that I use? I'm not positive as to which one I have on the car and won't be able to check until this afternoon.

- I removed the epoxy from the cover screw on the MPS foreseeing that it would need adjustment. However, I've never fiddled with one and don't know what to do one I have access to the inner screw. I'll search the forums for insight there.

- Trigger points looked great and worked fine on the old motor. Take a look if you like (not that the photo shows the critical parts): http://farm1.static.flickr.com/171/4183809...47a5c1730_b.jpg

- How much fuel pressure do you recommend while using this cam?

Thanks!!!

Also, did you get your distributor drive gear installed in the correct orientation?

I would start between 32 psi and 35 psi.

How does this look Mark? This is at #1 at TDC:



What 'cha think?

Looks right on!

Excellent! Cool graphic.

done it myself ...

Ditto

I will do a test tomorrow.

engine with 9550 cam
stock 043 MPS
I'll play with the fuel pressure while its hooked up to a LM1 meter and see if you can get anywhere near the correct AFR across the rpm range including WOT.

If I were you, I would throw some resistance in series with your TS2 (Head Temp) around 270 ohms for starters...it can make a HUGE difference...your symptoms sound similar to mine until I added a resistor. Your motor is running too lean. Or better yet, go down to radio shack and get a variable pot ($3) 0-1000 ohms and set the pot for about 270 ohms for starters...I think you'll be suprised the effect it has on a stock djet. I found that 470 ohms was perfect for my motor.
This is a cheap fix, and easy to check out.
Mark

I guess I can swing by and get a Pot too and test that to see how much it changes the AFR.....

by the term pot you are meaning potentiometer?

Geoff, is this(putting more resisitance in the circuit) helpful even after you have done your 043 MPS adjustments?
Just wondering if I should get one of these hooked up since I am getting close to having my motor finished up...just picked up a brand new CHT sensor today.

Not really as I set up the MPS to have a correct AFR thoughout the rpms range. If a engine needs a richer mix unplugging the temp 1 sensor adds 10% more fuel for a quick fix. Makes for harder starts too.

Geoff...when you say "correct AFR throughout..." are you saying for the 'typical' djet setup...doesn't that vary from year to year, i.e. 74-76 due to the different ECUs, even if the smog is removed and with diff. exhausts? It seems to me there are too many variables (unless of course you know them ahead of time).

Here's Brad's 2 cents from an earlier thread:
"If adding a lot of ballast resistance makes your 914 run better, then do it! Be aware, however, that adding too much may make the mixture vary once the engine is fully warmed up, possibly causing drivability problems.

This chart is from my ECU web page:
It shows the relationship between the Cylinder Temperature Compensation (CTC) circuit output voltage and the resistance of the TS2 (also called the CHT sensor) plus any ballast resistance. Higher values of CTC Vout translate to richer mixtures. The blue trace is for an 037 ECU with an 012 TS2 and no ballast, the other traces show the effect of increasing ballast, up to 500 ohms. The temperature ranges on the chart were deduced from calibrating the resistance values of the TS2 to actual temperatures.

What you see is that if you add between 50 and 270 ohms of ballast, you richen the mixture only through cold start and warm-up. If you add 500 ohms, now the mixture varies once the engine is fully warmed up. The ECU circuit is designed to linearize the TS2 characteristic and to cut off its effect once the engine is fully warmed up."

Ok, the 2.0L 74-76 Djet main parts are basically the same ECU's with the addition of the fuel cutoff to reduce emissions at overrun. The MPS's are the same, 043s.
73 2.0L stuff is not the same.

I see you can richen the mix by adding 500 ohms but how much does it change the AFR? Just pluging something in and going "wow, its better" is too seat of the pants for me.
I am working on a 0-1000 ohm variable resistor right now.

I did some fuel pressure testing this afternoon. going to 35lbs of fuel changes the ratio a half point richer which is alot really. So for some who are getting a slight lean miss or pinging under heavy load (ie up a big hill) can try this after sending out the injectors for a cleaning. Old dirty injector will of course run leaner unless they are sticking open.

Exhaust only comes into play if you go to a header which makes the whole engine more efficent meaning the old setup will run leaner.

which reminds me Geoff.
My car runs a Euro race header....

sorry

shit

Sounds like it is running on the accel enrichment alone. Maybe you forgot to plug the trigger points wire back into the distributor?

Thanks for all your feedback! I've been keeping quiet, because until last night I haven't had much tinker time.

I ditched the MPS I was using and installed a 43 that I had on the shelf and the car runs and idles. The PO (of the MPS) adjusted it for his motor (which wasn't stock either), but I don't know exactly what he did beyond turning the screw.

I adjusted the timing per the Haynes manual, and it seems too retarded. I stopped on my test run and gave it some more advance it pulls pretty hard nearly to redline. Though it seems like it's still running a little lean at higher RPMs. I'm going to check the fuel pressure tomorrow and will likely up it a few pounds.

I'd love to learn more about putting a resistor (fixed or a pot) inline on the TPS and perhaps on the head sensor as well. I probably need to fidget with the MPS a bit more as well.

Tomorrow I'll adjust the valves for the first time since starting the motor, dump the oil and will also hook up my VDO CHT and oil temp gauges. It's too scary trying to tune this thing without having grips on the basic temps.

Thanks again!

Randy,

I've got an LM1 wideband sensor, but you'll need an exhaust bung.

Thanks Mark! I'll be a WCM in Napa on Saturday and I may get access to the dyno and sniffer while I'm there. I don't know though... I haven't been there in over a year and it all depends on the owners mood.

Resistor on the Throttle Position Switch won't do anything good... It might, on the CHT sensor though. (AKA Temp Sensor II.)

--DD

Slip of the fingers (or my mind?), thanks!

Dyno?!?!?!?!?!

CALL ME on Sat!!!

It's just a SMOG dyno, so no HP numbers and KD isn't especially open to having anyone other than customers on it. I don't even know if I can have access to it. Oh well.

I'll give you a call on Sat, but I'll honestly be swamped over at WCM with my car and Eli's Fiat (my old Sedan). Feel free to swing by of course!

I'll come by.

My understanding is that SMOG dyno's aren't really setup up for tuning of any sort. But that's hear-say. I'd love to get some first hand experience.

It'll be great to see ya, just please don't mention the dyno bit when you stop in. Like I said, KD (the owner) might get his panties in a bunch if we start talking about using it. Eli will have to bring it up, but only if the atmosphere is conducive to such.

See ya Sat,

So I drove the car a bunch today and here's what I'm experiencing -

- Runs rough at idle when cold, almost sounds like it's missing a little
- Smells like it's running rich at idle as well
- Pulls very strong and seems very responsive in 1st gear, revs right up to nearly redline (I'm not pushing it all the way up yet)
- Once in 2nd - 5th, it seems a little sluggish and cuts out at higher RPMs when I really get into it. Acts like it's not getting enough fuel.

So, rich at idle and maybe lean at speed. My new CHT sensor and gauge are now installed, but it's not registering anything. I didn't cut or shorten the leads and bent the ring and not the wire to make it fit... anyhow, that's another problem.

- Running a 43 MPS that's been adjusted to an unknown setting by a previous owner
- All other FI components are stock '73 2.0 bits (I think!)
- Using a new Raby 9550 cam
- Oil temps are cool, at 150ish deg on this cool afternoon/evening.

I can lean it out at idle by adjusting the ECU. I'll check the fuel pressure tomorrow.

Cheers,

engine harness in good working order? you do own a multimeter, correct?

took 3 old engine harnesses to make one good one, but it fixed many, many little problems, some of which sound like what you're describing.

i found brittle & cracked wires even inside the hard plastic protective sheeting.
i had to cut it way down to get to still soft wires.

just one more thing to check ...
Andy

The harness worked great a few months ago, but of course it's possible something could have gone a wonky when I pulled it off the old motor and put it on the new one.

I'll check it out if everything else checks out. Thanks for the suggestion!

Time for Megasquirt!!

What cam do you have?

If itsa VDO CHT sometimes ya have to go red to black/black to red when hooking em up to get it to work.

To temp tune the MPS have a helper hold the rpms at 2500 with the gas petal and adjust the inner screw to the "Best" smoothest/sounding engine speed.

I would also look at the dizzy advance to make sure its not sticking. lube the advance plate with a shot of PB BLASTER and move it to make sure its free.

- Raby 9550 (as mentioned above. )

Megasquirt is being planned for a future motor, but I'm pretty confident I can get the D-Jet working to my satisfaction for the time being.

Did you move away from Petaluma already?

That's odd! It is a VDO CHT gauge and sender, so I'll reverse the connections first thing to see if that works. Thanks!



OK, I'll give it a try.



The dizzy is practically new now that I've rebuilt it and the plates aren't sticking. However, I'm having to run the car pretty advanced right now. I can't figure out my advance with my timing light, but I'll be using a better one this weekend and will be able to figure out what's going on there. I tried setting the advance per the haynes manual (27* BTDC @ 2500), and it's utterly gutless at that setting. Another clue perhaps?

How much vacuum does your engine have at idle while warm? How much does it pulsate?

Could it be that you have some leaks?

Oops, missed the post about the cam. D-jet should be ok then.

And yeah I did move already. I decided to move down to SF to be closer to Kylie, but I still commute up to Santa Rosa for work so I am up in your neck of the woods every day.

Do you mean 3500 RPM? Because that's where it's supposed to be set... Vacuum hoses disconnected, of course.

--DD

Yes, 3500 RPM, but with the lines connected. I'll disconnect 'em when I time and tune again tomorrow in Napa. I think I was using the Haynes procedure, and I don't recall it mentioned disconnecting the lines. What? Haynes made a mistake? I'm sure this is really old news around this joint, but, well, I don't spend ALL my time here.

Well, at least you're commuting the better of the two directions! We should do lunch or grab a beer after you get off work sometime soon.

Don't forget to call me when you make those plans.

Who are you and why do you keep stalking me?

Nice seeing you today! After you left I finished bleeding the brakes after installing the four new lines and Porterfield R-4 pads. Got the car on the ground and timed the stupid thing properly. It was really far advanced. I took it for a drive up the block after setting the timing and it ran maybe 20% better.

Brought it back in and then adjusted the MPS. Wow, that was the ticket! Now it's 90% of where I want it and it's pretty darn peppy!

It's still running a bit hot though when driving at a steady speed/rpm above 55/60 MPH. I'm going to try the potentiometer on the TPS (Just kidding Dave!) CHT sensor and see if I can't get things to cool down a bit more.

The VDO temp gauge (thanks for the tip about revering the leads, it works now) has been reporting between 300 - 355*, even with the timing set correctly. Oil temps are fine and have been steady at 160. That's a bit warm on the heads though, right?

The Porterfields seem great, though I know my front calipers could use a good 'ol rebuild. Hard to want to put much effort or $$ into them with the aluminum S calipers and five lug setup on the shelf. That'll be for the fall though.

Thanks everyone and I'll let you know how the pot on the cht sensor works out,

I've been solid at 250 on my CHT. This week it hit 300 probably from the hot weather. And speaking of weather, you're doing your VDO temp adjustment math, right?

VDO temp adjustment math? Are you just f'ing with me now? I probably deserve it for one reason or another.

So you're kidding, right?

They are calibrated for 70F outside air temps.....

Great to know! So if it's 90*, then I need to subtract 20* from the indicated temp. Cool. It was probably around 70* when I drove home this evening from Napa to Santa Rosa, so I still think I'm running hot. However, wouldn't I expect to see the oil temps come up above 160'sh if the head temp was consistently between 300 - 350?

Randy, read this tech article we just put up in the 914Info Section.

Tech Article