plug leads problem

[Quanta]

Looking on this forum I found that the NGK lead set 4395 would fit as it is for the 91 Isuzu Impulse. When I bought a set and tried to fit these leads were too short by 9 inches. Is it possible that I needed the lead set for the 4WD? Are they longer? I also would like to know how often it is recommended to replace the dual ignition coils? This forum mentions the MSD 8224 coils as a replacement. I'm having ignition problems and I'm not sure if it's my plug leads (replaced last year with high quality leads) or plugs (NGK Iridium last year as well) or the coils. My M100 has 140K on the clock and I don't have any history so I don't know if they've ever been replaced. I would rather replace the coils alone than start over with the leads and plugs since these should still be good. Any & All comments are greatly appreciated! Thanks!

PS. this is a Federal car and I'm in San Francisco.

[Brit-Car-Nut]

A lot of Isuzu parts interchange, but things like plug wires will be different because Isuzu put the coils in a different location than Lotus/GM did. The Kingsborne plug wires seem to be the preferred solution and they still give a discount if you ask for the LEC promotion.

[Enright]

I would put money on a misfire being caused by the coil packs being old. 140,000 sounds like you've done very well out of them, if those are the originals. Most give up before that - I think mine went around the 100k mark but am not sure.
Watch out for the MSD's - the casings on them are a bit fragile and easy to crack if you're a bit ham-fisted when screwing them onto the backplate.

[nicowalker1]

I recently had missfire problems, especially when on boost. Changed the coilpacks and hey presto, cured!

[Quanta]

Now I've got new coils and new plugs. when idling if I pull either 2 or 4 the car has no response (pulling 1 or 3 causes engine to almost die or die) but I can hear the spark grounding on the head. Seems they are not igniting but also seems there is spark coming to the plugs. Could the wires be sending some spark but not enough? These are 1 yr. old performance wires & appear to be in good shape still. Really at a loss to fix this ignition problem and ANY HELP will be GREATLY APPRECIATED! Thanks!

[GeoffSmith]

As you've lost 2 & 4 it is undoubtedly fuel related:

http://wikilec.9600.org/index.php/Dead_Cylinders

[Quanta]

Can anyone help me with the location of the connector IHC - B5? This has to do with the fuel injectors as my problem now seems to actually be fuel related. I cannot find any diagram that shows me Exactly WHERE this connection is physically located on the car. If anyone does know, please tell me or show me a picture if possible. Thanks again in advance!