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Posted by: Nate Nov 26 2014, 03:36 PM

Hey everyone! Hope you are all preparing for a nice thanksgiving.

Wanted to see what ideas you guys had about my original FI 2.0 from 73. Some of you may have seen a few other threads of mine but I'll give a little synopsis. I rebuild the motor in my garage. New Pistons and cylinders, all new bearings, lifters. Ground crank and cam. Heads rebuilt by a reputable shop. For the rest of the car. New fuel lines, cleaned and coated fuel tank. New fuel filter. Cleaned and flow matched fuel injectors. Rebuilt distributor. Tuned dwell angle and set static timing.

So I've done all of that and the car won't stay running. It'll start and run for 20 seconds with a high idle (approximately 2500 rpm's) and then it will die even if I'm feathering the throttle.

I'm looking for ideas as to what and how to troubleshoot the car. IF this car was a person I'd strangle it to relieve my frustration.

P.S. I went through the ecu harness and ohm'd everything out and there are no shorts in the wiring and the grounds are solid. I also replaced the throttle position switch and have that set up according to the book and have messed with the idle mixture knob a bit.
Anyone have any ideas on where I should go from here?

Thanks and I wish everyone a good safe holiday.

Posted by: saigon71 Nov 26 2014, 04:21 PM

Have you tested your fuel pump?

Posted by: gasman Nov 26 2014, 04:32 PM

Got to put a gauge on the fuel system..(fuel rail). Also try replacing the fuel relays.

Posted by: Nate Nov 26 2014, 04:41 PM

I have not bench tested the fuel pump but I can see it pumping fuel through the clear fuel filter while cranking the motor. I will look into the fuel relays. Thanks for the tip. I have not had a chance to check fuel pressure as I don't have the necessary apparatus and haven't built one yet.

Posted by: saigon71 Nov 26 2014, 04:59 PM

Fuel pressure test should show if the pump is working properly. I picked up a kit at Harbor Freight for less than $15 (I think) to check fuel pressure. Just pull the bolt out of the drivers side fuel rail and hook up the gauge.

Keep us posted on what you find out.

Posted by: 914_teener Nov 26 2014, 05:31 PM

Find somebody close to help you.

Posted by: Nate Nov 26 2014, 05:34 PM

Good call on a harbor freight fuel pressure gauge. I'll pick one up and let you guys know what I find!

Posted by: toadman Nov 26 2014, 07:56 PM

Although they are nearly bullet proof, I had starting problems that I traced to a bad ECU/fuel injection brain. I found it by accident. I was troubleshooting and accidentally touched the ECU and felt a hot spot on the case. Something failed inside and it generated some heat that heated up the outside of the ECU.

Posted by: boxsterfan Nov 27 2014, 12:13 AM

Cylinder Head Temp Sensor?


Been through the pbanders site?

http://members.rennlist.com/pbanders/DJetParts.htm

Posted by: Java2570 Nov 27 2014, 09:56 AM

Check out your trigger points in the base of the distributor, maybe swap them out with another set; also make sure the connector is secure and not vibrating loose when the engine is running.
Check the condition of the points plate ground wire in the distributor.

Posted by: Luke M Nov 27 2014, 10:08 AM

Cylinder Head Temp Sensor?

I agree check it.. A friend and I spent several hours looking over his engine to finally find a bad sensor.. it was a quick fix once we figured it out.. We never thought about it as it's out of sight out of mind type of thing..

Posted by: pvollma Nov 27 2014, 01:46 PM

I'm interested in adding a pressure tester to my toolbox. Is this the Harbor Freight pressure tester you referenced?

http://www.harborfreight.com/fuel-injection-pump-tester-92699.html

However, the description states that it does not work with Bosch systems.

Posted by: saigon71 Nov 27 2014, 08:21 PM

Just checked...That's exactly the one I bought. I just used a hose clamp on the fuel rail and used the supplied fittings up to the gauge.

It did what I needed it to do. Maybe they are referring to newer Bosch FI systems?

Posted by: Nate Nov 28 2014, 01:18 AM

This points plate ground wire that you speak of. Is it a small braided wire type of deal?

Posted by: Java2570 Nov 28 2014, 06:47 AM

Yes, the small braided copper wire is connected to both plates.

Posted by: Nate Nov 28 2014, 04:18 PM

Okay guys. So, I resoldered the points plate ground wire since that had come off of the top plate. I also verified that the fuel pressure was at approximately 30psi. Still no dice. I'm going to pull the head temp sensor and test that. I'm kind of worried as to what I do if it's bad though since they are so hard to get ahold of for the 1973 2.0L. I guess mine requires the 0 280 130 017 Bosch part number which are near impossible to obtain.

Posted by: 76-914 Nov 28 2014, 08:19 PM

You can add a resistor to the std temp sensor or install a variable resistor instead.

Posted by: bandjoey Nov 28 2014, 09:03 PM

Points and condenser or the little electronic gadget that replaces them? Like Pertronix?

There was a thread talking about the screw holding the Pertronicd plate to the distributor was grounding the unit and to cut doen that screw.

Posted by: Nate Nov 28 2014, 09:05 PM

Alright guys. I've tried everything you have recommended I check. Just finished installing a potentiometer in line with the cylinder head temp sensor and have messed with different ohm values to try to get it to run. This is a 73 and I'm not running the ballast resistor. Could that be the problem?

This car ran 10 years ago. I just rebuilt the motor but didn't change any sensors or electronics aside from rebuilding the distributor with new cap, points, etc. I should also mention that it ran better than this a few weeks ago before I realized the injectors were gummed up and sent them off for cleaning.

Any other diagnostics I can perform to get this thing going? It needs to get back on the road and it's so close!

Posted by: Nate Nov 28 2014, 09:06 PM

Joey. I'm using stock style points and condenser.

Posted by: bandjoey Nov 28 2014, 09:24 PM

Sounds like it's time for a BBQ and repair party. Good luck.

Posted by: Java2570 Nov 28 2014, 09:35 PM

Yep, being in Southern CA you should be able to get some local help in your area. Offer up a beer & food event and you'll get some good help! The ballast resistor will only add about 270 ohms to the resistance of the CHT. You could try disconnecting the intake air temp sensor (on the plenum, right by the TPS)...it will slightly richen the mixture. See if that helps at all. I've also heard of people getting stuck injectors after getting them back from being cleaned. I'm sure at this point, you feel like you're chasing your tail...nothing beats getting a new set of eyes on the issue(s).

Posted by: boxsterfan Nov 28 2014, 10:47 PM

Tried a different ignition switch? Injector to ecu connectors on the right ones? Spark plugs wires going to the right locations? Cracked relay board? Bad/intermittent voltage regulator? Pinched fuel line (is the fuel pump fairly quiet or does it make a bunch of noise....ie sound too loud)?

Very tough problem. Sounds like it cranks. Sounds like you got fuel. Sounds like you got spark.

Posted by: Nate Nov 28 2014, 11:38 PM

Could be a pinched fuel line since I dropped the tank back in. But I don't really think so. I'll check that tomorrow. Connectors are on the right injectors. Plug wires are routed correctly. Relay board looks perfectly fine. Haven't checked the voltage reg but I will.

Ive pretty much run out of the big ticket items to check. Even if there is a peripheral item that is malfunctioning it seems like the car should run somewhat. All that I've been able to muster is about 10 seconds of run time and that is after I haven't tried to start it for a while. After that initial 10 second run, it shuts itself off and then all I get is for it to run for a couple seconds and then it shuts off each subsequent time I try to start it.

Posted by: boxsterfan Nov 29 2014, 12:20 AM

My car has been on jackstands all fall since a failed fuel pump. I had the tank back in a couple times. One time it ran but wouldn't stop with turning off the key. Eventually degraded to a no-start.

In your case, perhaps enough gas is getting through a pinched supply line. Once you start the car though, the suction from the pump closes the supply line completely and there you go.

I put in the 30R9 fuel hose. Stuff loves to bind up.

Posted by: gasman Nov 29 2014, 07:13 AM

When the engine stalls....do you still have 30 PSI at the injectors?

Posted by: Bartlett 914 Nov 29 2014, 11:54 AM

My first thought was a pinched or kinked fuel line but this does not account for the high idle. You may have a couple of issues. I would look into a pinched fuel line first.

Posted by: Nate Nov 30 2014, 04:05 PM

Okay. So I checked for a kinked fuel line and did not find one. Gasman, I have noticed that I have 30psi while cranking the motor but as soon as I stop cranking the psi immediately drops to 20psi and then slowly falls to zero from there.

Posted by: boxsterfan Nov 30 2014, 04:22 PM

What's the PSI look like right after the car stalls? Or as it is headed into stalling?

Other places to check for "kinked hose" (besides up at the front gas tank) are where you connect the hose to the fuel rails. Also, where you connect the fuel rails to the injectors. For example, when I was putting my new fuel line in, I didn't quite get the clamp up far enough and it was half on/half off the end of the fuel rail and pinching the hose.

Posted by: Java2570 Nov 30 2014, 04:35 PM

You never really said whether you were using the original fuel pump or a new replacement. I ran my car earlier today and still am showing about 10psi on my inline pressure gauge. It shouldn't fall to zero that fast....perhaps your fuel pump is either not working correctly or on it's way out? I think you said you bench tested the pump but maybe the pump wiring has got an intermittent issue while the car is running.

Posted by: Nate Nov 30 2014, 05:02 PM

I'm not sure what the fuel psi is right before it stalls. I haven't been able to start it today. I will try to check that out though. There are no kinks in the lines between the fuel rails and injectors either. I'm not sure if the pump is original or replacement. It appears original. When I say the pump falls to zero, what I mean is that after the fuel pump stops running the psi immediately drops to 20 and then it takes another 45 minutes or so for it to slowly drop from 20 to 0. I know that the pump has a check valve that holds pressure after the pump shuts off but I have read that the chances of that effecting anything as long as the pump is running are minimal. But I guess at this point I'm down to the less common problems...

Posted by: Bartlett 914 Nov 30 2014, 06:08 PM

The Fuel pump has a check valve in it. The fuel is leaking back into the tank past this valve. This amount of pressure drop after the pump shuts off is pretty common and not a real problem

Posted by: Nate Nov 30 2014, 06:23 PM

That's the impression I was under. Thanks for confirming.

I think I'm going to try some new FI points in the bottom of the distributor. These weren't part of my rebuild kit and I figure it couldn't hurt to try them out because they are cheap.

Can anyone confirm which distributor I have though? There is stuff crossed out so I want to be sure I have the right one and order the right points.



Looks like 039 905 205 A. This doesn't appear to be the right distributor for my year (73) but I know the car ran before with it.

Posted by: Phoenix914 Dec 1 2014, 07:11 AM

The fuel filter may be partially clogged and restricting the fuel flow. You may want to replace it for good measure.

I was having a similar problem with my '73 - it would start sometimes and run for a few seconds, and then die and not start until it sat for a while. I finally took the fuel filter off and found it was really clogged. I haven't put a new one on yet, but that was definitely part of the problem, if not the entire problem.

Posted by: Java2570 Dec 1 2014, 07:53 AM

The 205A was for '74 2.0L, it should work ok for your car....not sure what was changed on your dizzy. Maybe it was recurved to be a 205A? 205B was the dizzy for '75-76.
As far as I know, the trigger contacts were all the same part # shared with all the different engines. Be careful buying new trigger contacts, I've heard that some being sold are counterfeit.....I don't think new units are being made anymore. Contact Bruce Stone for good trigger contacts, he should have some.

Posted by: 914_teener Dec 1 2014, 09:21 AM

So..... why would you check the trigger points before you would check flow at the injectors?

Hint:

Rhetorical quesrion.

Posted by: bandjoey Dec 1 2014, 10:15 AM

Fuel filter flow on backwards?

Posted by: Nate Dec 1 2014, 12:11 PM

Fuel is flowing through the filter the correct way so that's not it. I'm not sure why someone would spend the money on the points before checking flow through the injectors. But my injectors are flowing so I'm moving up the line at this point.

Posted by: 914_teener Dec 1 2014, 01:38 PM

At the right rate? If not then that sounds like something to check out...assuming you are referencing the trigger points and not breaker points.....unless your are running something else. Those rarely go bad...although I have had a set go bad......the fiber blocks were almost worn out.

It was suggested a while back that it just might be a bad ECU....if all other components on D-jet check out...logically...then you may want to consider a known unit that is confirmed on an engine that runs with no problems.

It just sounds like you are frustrated and chasing your tail from your posts. Do the logical things in the right order and you will find the problem.

If you don't know what those steps are.....then you will need to start from the beginning to eliminate something you missed.

There are plenty on posts via searching here on this site plus the vaunted Anders site.

Ask me how I know all this?

Posted by: Nate Dec 1 2014, 08:28 PM

I pulled the plugs today. Don't really know why I didn't do this sooner. Probably because they were brand new with the rebuild and I didn't think they would be at fault. They were a bit oil fouled. Possibly from the break in of the engine. So I cleaned them up and will see what happens. I'll keep you guys posted.

Posted by: gasman Dec 1 2014, 10:55 PM

Remove and clean the relays on the board in engine bay. There are four spaces on the board with the two middle relays controlling fuel. If you can, swap them with your headlight relays and give it a try. Make sure the fuses on the board are clean and tight also. There are tests you can do on the board if you are good with electric diagnostics

Posted by: Nate Dec 3 2014, 08:00 PM

A little more info to add to this dilema. I stepped away from it for a couple days to clear my head haha. Went back at it today for a bit. Tested spark at all plugs. All strong blue sparks. Tested fuel through the injectors into jars and was getting fuel. Funny thing I did notice today, engine seemed to run better while cylnders 1 and 2 were not firing. It would actually idle for a few seconds. Albeit it was a rough idle. I don't know if this means anything.

Summary of what we know:
Getting spark
Getting fuel through injectors
CHT sensor set up with a variable resistance pot and set to 1400 ohms for "cold" starting
MPS checked out with the ohm meter at 90 ohms and 350 ohms on the appropriate terminals and when I apply vacuum (read: suck on the port) it is holding the vacuum.

Posted by: Java2570 Dec 3 2014, 08:27 PM

Since you are going through all of this testing, etc....when was the last time the valves were adjusted?
I would put that on the list of things to double check.

Posted by: Nate Dec 3 2014, 09:06 PM

When I rebuilt the motor. Motor has maybe 20 minutes of running time on it total.

Posted by: boxsterfan Dec 3 2014, 10:04 PM

Can't remember if you checked these:

Ignition switch? I don't know what/how to test though.

Throttle body butterfly valve operating properly?

Try change the round black relays on the relay board for the FI?

Maybe AAR stuck shut? Try disconnecting vacuum hoses from it completely.

Trigger points on distributor? Can't remember if you looked at this

Borrow an MPS to try?

Borrow an ECU to try?

Posted by: Nate Dec 3 2014, 10:34 PM

Throttle body and TPS are working and busted according to the book.
FI relays wouldn't be a problem if I'm getting fuel through the injectors right?
I'm getting good spark and I don't think that would be the case of the trigger points were bad. Or maybe not?
I will try disconnecting the AAR hoses in case it is stuck closed.
I'm starting to think that the ECU may be to blame so I may be trying to see if someone has a working one I can borrow to troubleshoot.

As always, thanks for the ideas and help. It is always appreciated.

Posted by: Bartlett 914 Dec 4 2014, 07:41 AM

Trigger points are associated with injectors not spark plugs. One set of points work with one bank. The other set works with the other bank. How did you test the injectors? Did you test them in the car or did you do something else?

Posted by: Nate Dec 5 2014, 02:20 PM

I tested the injectors on the car.

Just wanted to let you guys know that I found the problem. Apparently, at some point, one of the bolts holding on the rocker assembly for cylinder 4 stripped right off the stud. I checked compression yesterday and was getting 30 psi on cylinder 4. So I popped the valve cover off and the issue was staring me right in the face. So I'm happy that I found the issue but also a bit confused as to how this occurred. Valves were all adjusted to spec during the rebuild. I guess it's possible that I cross threaded the bolt onto the stud but I was very careful during the process. Both the stud and the bolt threads were stripped.

Posted by: Phoenix914 Dec 5 2014, 02:33 PM

Glad you found the problem, Nate.

Posted by: Nate Dec 5 2014, 02:44 PM

Seriously! Got the job offer yesterday that I'd been gunning for and figured out the porsche problem. Haven't had that good a day since...god knows when! Haha. Thanks for all the help. All your guys' help was paramount to me finding this issue.

Posted by: 914_teener Dec 5 2014, 03:36 PM

Question:

Did you degree the cam in at zero lash?

Or did you set the lash and then degree the cam?

Posted by: Nate Dec 5 2014, 04:41 PM

Please explain? I'm not sure what you're asking. The lash between the cam gear and crank gear?

Posted by: 914_teener Dec 5 2014, 09:17 PM

Nate:

Maybe something went wrong with your cam assembly...kinda late now the motor is in the car.

At this point I'd put your rocker assembly back together and then reset the valve lash to spec.... .006. and make sure the motor spins freely. You also may want to check the timing marks against the distributor on the No. 1 cylinder...just a check with both valve covers off.

Then see if it will fire and stay running now.

Posted by: Nate Dec 5 2014, 10:46 PM

I know that I lined up the cam gear and the crankshaft gear correctly so that's not an issue. I also made sure that the machine shop indexed the cam gear correctly to the cam shaft so that's not it either. The motor spun freely before I put it in and I checked valve clearance to the Pistons during assembly. I'm kind of thinking that the bolt must have just been cross threaded onto the stud. It's been a pain diagnosing but I don't believe there is any collateral damage. I think I got lucky.