Jensenman
Jensenman SuperDork
11/29/09 5:47 p.m.

Story so far: the Jensenator has a Series 5 normally aspirated 13B rotary (1989-1991 type engine). S5's have an electronic oil metering pump which will, if it gets in a snit, cause the ECU to cut the trailing ignition ('limp mode'.) I was having problems with that happening, swapped another OMP onto it and it happened again. So I decided to swap a Series 4 (1986-1988) mechanical OMP and ECU into my car and get rid of the limp mode thing. So I mated the S5 harness to the S4 ECU, swapped on an S4 front cover and OMP, etc.

The wiring is almost exactly the same between the two; there are two wires whose colors do not match but their functions are clear and after much research (I have both the S4 and S5 wiring diagrams) they were connected. With the exception of the MAF, MAP and TPS sensors, everything is the same; I have the correct TPS and MAP, the S5 MAF is compatible with the S4 ECU (been done lots of times and I got the straight lowdown on how to connect it). I now have everything I need: spark at the plugs, tach operation, +5V reference to the sensors, +12V at the injectors etc but I don't have injector pulse. Dammit.

I clipped one of the signal wires to a primary injector, connected an LED ('noid light'), when I switch on the ignition I get a momentary blip but no injector pulse when turning the engine over. I have checked wires till I am dizzy. Any idears out there?

P71
P71 GRM+ Memberand SuperDork
11/29/09 5:53 p.m.

Carburetor and a distributor. Sorry, that's what my rotary has, I've got nothing except "check grounds". I know fuel injectors don't like bad grounds.

aussiesmg
aussiesmg SuperDork
11/29/09 7:10 p.m.

This is why I love the Weber 48 IDA, sorry no help

Jensenman
Jensenman SuperDork
11/30/09 10:15 a.m.

Surely there is SOME bright person out there with an idea?

Sofa King
Sofa King Reader
11/30/09 10:48 a.m.

I don't know anything about 13b electrical, but ... I know that many systems have a fuel cutoff if there isn't oil pressure. Could you have an issue other than your wiring that is causing the problem? Sounds like you might have had a problem that sent into "limp home" mode before, maybe that same problem is causing this issue on your current system.

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