Reassembled Plenum to Motor - No Start - 0 RPM Cranking

[dondon]

Hi

I think I've diagnosed a future ECM rebuild in my future, however I decided I wanted to put the plenum back on, make sure the car is running as it was before then send the ECM away.

Well after putting the plenum back on (this is #2 for me - 1st one solo) the vehicle cranks, but does not start. While I didn't check the actual fuel pressure, on touching the shrader valve, lots of gas was available. So I'd like to think that isn't an issue, I then made the room dark, hooked a spark plug to #1 observed no spark. I also somewhere in that sequence observed the RPM while cranking on a Tech 1 and it showed 0 RPM.

My gut says 1 of the 4 connectors under the plenum to the DIS is not seated correctly, however the back 2 (observable with a camera phone and MAP sensor removed) appear in good shape. I saw some discussion about accidentally unhooking the coil connectors when plugging in the DIS connector... If they are the two observable from just behind the fuel pressure regulator then they appear pretty tight as well. I was also able to remove the DIS connector and take some photos to verify the pins looking in good shape.

Any thoughts on what idiotic thing I forgot when reassembling or where to check or should I just pull the plenum again and hope to observe something amiss?

[XfireZ51]

Originally Posted by dondon

Hi

I think I've diagnosed a future ECM rebuild in my future, however I decided I wanted to put the plenum back on, make sure the car is running as it was before then send the ECM away.

Well after putting the plenum back on (this is #2 for me - 1st one solo) the vehicle cranks, but does not start. While I didn't check the actual fuel pressure, on touching the shrader valve, lots of gas was available. So I'd like to think that isn't an issue, I then made the room dark, hooked a spark plug to #1 observed no spark. I also somewhere in that sequence observed the RPM while cranking on a Tech 1 and it showed 0 RPM.

My gut says 1 of the 4 connectors under the plenum to the DIS is not seated correctly, however the back 2 (observable with a camera phone and MAP sensor removed) appear in good shape. I saw some discussion about accidentally unhooking the coil connectors when plugging in the DIS connector... If they are the two observable from just behind the fuel pressure regulator then they appear pretty tight as well. I was also able to remove the DIS connector and take some photos to verify the pins looking in good shape.

Any thoughts on what idiotic thing I forgot when reassembling or where to check or should I just pull the plenum again and hope to observe something amiss?

If no spark, then ignition module must not be firing coils. Undo the plenum and yes check the harness connectors. Make sure crank sensor is plugged all the way into DIS. No need to disconnect ignition housing connectors at back of coil packs, just the 4 connectors on Ignition module itself.

[LGAFF]

I think I had this same issue...bent PIN on the DIS, easy fix

[dondon]

Thanks to everyone for the help.

Today I took plenum off again. One pin looked a little fishy, I corrected as best I could. Reassembled... No Start.

I began to scour the net for information, made an offer on a DIS module currently on EBAY. Researched more, and went back to chart A-3 (page 3 of 4). Followed the eventualities and ended up checking the fuse for the "Guages".

It had blown. Replaced the fuse with another fuse in the box. Turned the key and car started right up. Apart from the ego blow and the loss of a day I'm pretty ecstatic about it. Wish I'd just checked the fuse... that may have been the problem all along.

---------------
Solution : Blown Guage Fuse (10A) replaced.

[Dynomite]

Originally Posted by dondon

Thanks to everyone for the help.

Researched more, and went back to chart A-3 (page 3 of 4). Followed the eventualities and ended up checking the fuse for the "Guages".

It had blown. Replaced the fuse with another fuse in the box. Turned the key and car started right up. Apart from the ego blow and the loss of a day I'm pretty ecstatic about it. Wish I'd just checked the fuse... that may have been the problem all along.

---------------
Solution : Blown Gauge Fuse (10A) replaced.

Another Solution for No Start Issues......noting the zero RPM as a primary symptom

[gbrtng]

Originally Posted by dondon

Thanks to everyone for the help.

Today I took plenum off again. One pin looked a little fishy, I corrected as best I could. Reassembled... No Start.

I began to scour the net for information, made an offer on a DIS module currently on EBAY. Researched more, and went back to chart A-3 (page 3 of 4). Followed the eventualities and ended up checking the fuse for the "Guages".

It had blown. Replaced the fuse with another fuse in the box. Turned the key and car started right up. Apart from the ego blow and the loss of a day I'm pretty ecstatic about it. Wish I'd just checked the fuse... that may have been the problem all along.

---------------
Solution : Blown Guage Fuse (10A) replaced.

The fuse blew for a reason - did you have the battery disconnected when you were working under the plenum?

[Schrade]

Originally Posted by gbrtng

The fuse blew for a reason - did you have the battery disconnected when you were working under the plenum?

Was thinking the exact same thing here.........

[dondon]

Originally Posted by Schrade

Was thinking the exact same thing here.........

I did initially, but while performing tests from the FSM, some of them required power so I did hook up the battery, then disconnected prior to reassembly.