Weird running issues

[Zaffer]

I haven't done a compression test yet, but hoping to this weekend since it'll be baby free! I keep leaning towards the AFM, but would like to check everything else before going that route. I'll check the vacuum lines as well to see if anything changes.

Thanks for letting me know about the cam timing. I didn't think a tooth off would effect the revving of the engine, but some cars have weird little ticks that others don't and head are still new to me.

[bradartigue]

I haven't done a compression test yet, but hoping to this weekend since it'll be baby free! I keep leaning towards the AFM, but would like to check everything else before going that route. I'll check the vacuum lines as well to see if anything changes.

Thanks for letting me know about the cam timing. I didn't think a tooth off would effect the revving of the engine, but some cars have weird little ticks that others don't and head are still new to me.

A tooth off affects the timing of one cam or another; worse yet, it almost always indicates some slack in between the head and crank, because the timing belts don't seem to fit snugly or correctly when things are out of line. I forget how many teeth are in the camshaft wheels but each one probably amounts to 6 or so degrees of timing, that's quite a bit off.

[Zaffer]

Update:

I checked the fuel pressure and it's where it should be. I figured out that the reason the car starts for a few seconds and then dies is due to the cold start injector pushing just enough fuel for this to happen. When I disconnected the CSI to check fuel pressure, the car wouldn't start at all. Once I reconnected it, it would start and run for a few seconds.

I checked the no. 1 injector connector for power and I have power on both leads. Is this normal? Also, with the car cranking/running, I don't see any pulsing with the test lights (one is LED and one is incandescent).

The dual relay is clicking on when I turn the ignition on and I don't hear it click off until I turn the ignition off.

The AFM is no longer an issue as I sent it off again to be inspected/rebuilt and the flap is once again working the fuel pump correctly. I confirmed this again by crimping off the fuel return line, which lets the car run normally, I'm guessing by forcing the injectors open by pressure alone, because as soon as I un-crimp the line, the car dies.

I re-checked the timing belt timing and it is still spot on.

I'll check the wiring diagram for the injectors to see if I can find anything there.

Any other ideas I'm not considering?

[RRoller123]

Supply and return to the rail could be swapped?

[Zaffer]

Nope, they are correct. I was looking at the wiring diagram and it looks like the dme is supposed to switch the injector on and off? Is there a signal the dme sees that maybe it's not seeing in my case?

[124JOE]

out on a limb but mabey your pickup screen is pluged?

[Zaffer]

Pick-up screen as in for the fuel, or signal for the dme? If fuel, the pressure is good while "running". If for the dme, where is this located, the distributor? Also, is this what signals the dme to "fire" the injectors?

[124JOE]

fuel sorry

[RRoller123]

Pick-up screen as in for the fuel, or signal for the dme? If fuel, the pressure is good while "running". If for the dme, where is this located, the distributor? Also, is this what signals the dme to "fire" the injectors?

dme = ??

[Zaffer]

DME = Digital Motor Electronics

[76was124]

Also, with the car cranking/running, I don't see any pulsing with the test lights (one is LED and one is incandescent).

One lead to the injectors is +12 volts all the time, the other pulses to ground (0 Volts ) very briefly through the ECU. All injectors fire together.

So if you connected the test light to the leads from the FI connector, it would be on most of the time and flicker off briefly. If you aren't, seeing it flicker, then your main injectors aren't getting the pulse to fire from the ECU.

Double check you have a proper ground for the injector circuit. There should be two black wires under one of the bolts on the intake manifold, close to the firewall.

There are other things to check like wire Injector wire continuity back to the ECU and whether the ECU is getting the pulse from the ignition to tell it to fire the injectors. ( could be a pick up coil problem with the distributor.) Did you gap it properly when you replaced it? Was the new magent, line side down? You could search the forum for help on checking the wiring further.

[Zaffer]

I didn't even think about the gap with the pick-up in the distributor! I'll check that and the grounds to see that they are okay. I'll also recheck the injector to see if it's pulsing with a pulse check tool.

Parallel thread of another person having the same issue: http://www.fiatspider.com/f15/viewtopic.php?f=6&t=31489

[Zaffer]

Update:

Checked the gap with the magnetic pick-up and it was WAY off. Corrected that, but still no spark. Checked and cleaned all of the grounds, including the 3 for the ECM, and they are all good. Checked the continuity between the coil and the ECM and it is good. Checked continuity of the temp. sensor in the "T" via the ECM connector and it is at 4.598 megohms! Checked the connector, and it is loose, but not enough to account for the continuity issue. I guess I'll be replacing the sensor and see if that corrects anything.

One quick question about the temp. sensor: Will the cold start injector still fire, even though the temp. sensor is bad? I guess I just figured that is the other injectors wouldn't fire, the CSI wouldn't either, but this doesn't seem to be the case. Is this correct?

[Zaffer]

Another update:

Got a new temp sensor and connector. Before I replaced the sensor, I tested the old sensor with the new connector (before splicing it in) so I could text just the sensor and it is within spec as it read about the same resistance as the new sensor, so I'm beginning to think it's a wiring issue.

Am I supposed to get any resistance reading between the head temp sensor and pin 13 on the ECU? I ask because I get the same reading whether I'm testing b/w pin 13 and head temp sensor or b/w pin 13 and temp sensor at coolant "T".

Also, when I pulled back the wiring cover at the ECU, all of the wires except 2 are white, but they look factory and untouched. Is this correct? The wiring diagrams I'm looking at don't indicate white wires nor any connection between the two temp sensors.

Any ideas would be great! Thanks!

[So Cal Mark]

a couple of responses back you mentioned no spark. Why would you be focusing on the FI if you have no spark?