Hey guys,
I picked up a built 88crx running a chipped p06 ecu, obd1 distributor, LS engine
Looks like a clean swap, conversion harness was used for the ecu and distributor and there doesn’t seem to be any hacked together joints.

I picked the car up non-running;
symptom was it would start, rev up to 2k rpm, hover there for a bit then drop to 1k-ish, stay there for a bit then the revs will drop off and it will die. (all within 3-5 seconds)
If abrupt trottle input is given then the revs drop off quickly and engine wont recover until you let off the throttle.
engine will increase rpms if you very gently start depressing the throttle.

Looks like some people tried to trouble shoot and repair it...

The most disturbing 'lets see if this will work' repair i saw so far is the extra pig tail from the ecu conversion harness
*sorry the pic is so dark*

It looks like that pigtail was for an external tuner, or vtec controller or something as most of the wires are spliced onto existing wires in the conversion harness...
well, some one took the wire that is spliced onto the main relay power pin of the ecu and shoved it into the fuse box, basically supplying two sources of power to the same pin...

I started going about my trouble shooting;
- has spark
- main relay is good *apparently they are notoriously bad on crx'es*
- has injector pulse *ish*
- injectors all read 11.5 ohm resistance
- fuel pump is good
- fuel filter is new
- timing is correct *timing marks on cams, and crank cogs all line up properly*
- compression is 195ish across the board
- swapped fuel pressure regulator and IACV with extra units and it made no difference
- I also pulled the jumper out of the ecu *activates the chip or runs the ecu on standard base map* and it made no difference

Sorry for the big back story but I wanted you all to have the background;
Now for the sanity check/reason this is in the engine management sub-forum...

When i said injectors had pulse *ish* I mean I’ve never seen injector pulse like this before... I used a solenoid test light, when you start cranking the engine over there is no injector signal for the first 3 rotations, then there is a very dim light then the next cycle it gets brighter than the next brighter still and this continues...

so this leads me to the next three questions;
- Will supplying two sources of power (one hot at all times, one only hot when key is on) to the same pin on an ecu fry it?
- Is the injector pulse that im seeing (non-existent on the first few rotations then increasingly more powerful each rotation) normal for start up on these cars?

 

u could do some more reasearch and actually tell what wire your talking about like A25. B6 etc. then smart people can tell you the effects it will have on your ecu. also their are different voltages 12 less than 5 you need to be very specific an you will get the help you need.

 

that extra pigtail your talking about is part of the conversion harness to go from obd0 to obd1
this is what one looks like

 

Yep, kinda figgured it was part of the conversion harness, but what I was saying is it appears to be a splice in for another external device and there was a power lead on that spliced to a pin on the ecu that sees power when the main relay is closed....

Any how, friend of mine brought by an obd 1 ls ecu, we plugged it in and it started rough but idled just fine after it warmed up... So a new burn chip later it should be good to go