Troubleshooting: 2.0 won't stay running Options

[gasman]

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

[Nate]

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.

[Java2570]

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.

[Nate]

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

[boxsterfan]

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?

[Nate]

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.

[Bartlett 914]

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.

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?

[Nate]

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.

[Phoenix914]

Glad you found the problem, Nate.

(IMG:style_emoticons/default/smilie_pokal.gif)

[Nate]

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.

[914_teener]

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.

Question:

Did you degree the cam in at zero lash?

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

[Nate]

Question:

Did you degree the cam in at zero lash?

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

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

[914_teener]

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.

[Nate]

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.