We are doing a swap on a 90 hatchback, STD, we have done the mpfi and the obd1 wiring.... Its a Z6 with Si tranny.. Anyway, we are getting spark, timing is perfect, turning over, compression is 150 all the way, getting fuel(not sure about the fuel pressure), injectors are pulsing... Just wont start. We got a code 41. O2 heater control.... Anyway, it will not start, grounded good... Tried another P28 ECU... We are lost. Any suggestions, sound familiar to any problems you have encountered>

 

ttt

 

1. that ecu code wont prevent startup
2. possibly weak spark from weak battery
3. strange that you can get fuel and spark and it wont start.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Audipwr1 &raquo;</TD></TR><TR><TD CLASS="quote">1. that ecu code wont prevent startup
2. possibly weak spark from weak battery
3. strange that you can get fuel and spark and it wont start. </TD></TR></TABLE>

Thanks for the answer, but...
1. We know that but...
2. We have the battery charged and are jumping it with another vehicle
3. Hell yea, tell me about it, haha. I dont know, we are gonna check the fuel pressure to see how good it is right now...

 

i would doublecheck wiring and make sure ur firing order is correct

 

firing order is correct, and i did recheck the wiring a few times, we started out with 3 codes, now we just have the o2.. we had crank angle sensor and intake air temperature, but we fixed those two.

How do you know if the injectors are actually spraying? We checked the pulse with a test light so we know there pulsing, we are getting 32 psi of fuel through the fuel filter, so thats good.... The only thging can be clogged injectors or something.....

 

have you checked for continuity between the injectors and the corresponding pin at the ecu plug?

 

I had a similar problem when I wired up my car (OBD1 GSR in an 89 Civic Si Hatchback).

Add to what you have said, I could smell fuel at the tail pipe, so I knew that the injectors were working.

I wasn't getting any error codes.

If I sprayed "starting fluid" in the intake, it would "kind of" start and then fall on it's face.

After talking to the nice guys at "Lightning Motor Sport" (Yes, that's a plug), they recommended that I look closely at the MAP sensor and also Throttle sensor. The idea being that the computer was supplying the wrong amount of fuel.

Using the factory manual's "trouble shooting flowchart", I found that I had two of the wires going to the MAP sensor swapped!

I fixed them and it started right up.

(sorry about the diatribe, but I thought others may find it helpfull)

Wes Vann

 

Well i do have a question... Non OBD harness at the ECU, plugs B15 and B16... I am not quite sure if they are in good, and i am not sure what exactly they go to on the OBD1 harness, cause what I could do is just run them to those wires on the OBD1 harness and see if that fixes the problem... I think they have to do with the ignition but I am not completely sure, and I do not have the CRX workbook anymore because we are on a new computer, so if someone could post that link up i would appreciate it.. Thanks for the help guys..

 

to the top

 

Well after closer look B15 and B16, are in good, and thats the reason there is no engine light for it. Are there any suggestions, I have no clue.. Reversed the TPS wires, gonna recheck the injector wiring, but they all pulse, so im guessing there working, unless all 4 are clogged, ANY ideas are welcome...

 

Did you use a 4 wire o2? I could be wrong but from what I have read you have to use a 4 wire when going OBD2

 

it is a 4 wire o2, on the downpipe of the DC header...

 

Have you checked and made sure the wiring is correct from o2 --- ecu

 

i run obd1 with no 02 sensor plugged in at all, doesnt matter you just run more rich

The MAP - TPS could be the problem. I recall I had a brief issue with that when i did it. from mpfi- obd0 you have to move those suckers all over the place

let us know what it is

 

Use the factory manual "trouble shooting flowchart" to check the MAP and TPS!!!

I "buzzed" my converted loom several times and even had a friend help me out. I've done a lot of wiring work on cars over the years, and yet misread the the factory diagram.

Wes

 

is your fuel pump even coming on?

 

Update - Pulled the fuel rail, with the injectors still attached, turn the key, fuel is spraying from all 4 injectors. So fuel is getting into the motor, unless something is clogged in the area of the intake to the head.

Wouldnt I have a MAP or TPS code if something was messed up from there? I have a code 41 and that is it, it should still start.

Checked the timing 3-4 times tonight, perfect, re timed it a few times, still nothing. Spark, Fuel, Timing, Compression...... ECU works good, code 41. That is it dude, no idea... The only thing it could be is no fuel getting into the motor, like something blocking in the runners or something, possible?

 

top please

 

did you make piggy back or just hack the wires?

i've had that problem b4 with the 2 yellow/blk wires that you have to tap to the resistor box.

please list Year of parts:
DIZZY
injectors
ecu

i'd first make the car run with obd-0 then do the piggyback/obd conversion. Makes for less headaches and troubleshooting easier.

hit me up on PM if you need more help
carlos
carlos_tss@hotmail.com

 

and i am guessing that when you turn the key the **** is actually cranking over just not starting?

 

How's your compression?

Timing belt is set correctly?

What distributor do you have?

 

it's your ignition coil had the same problem, after I did my odb0-odb1 and mpfi conversion,

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Cnote &raquo;</TD></TR><TR><TD CLASS="quote">did you make piggy back or just hack the wires?

i've had that problem b4 with the 2 yellow/blk wires that you have to tap to the resistor box.

please list Year of parts:
DIZZY
injectors
ecu

i'd first make the car run with obd-0 then do the piggyback/obd conversion. Makes for less headaches and troubleshooting easier.

hit me up on PM if you need more help
carlos
carlos_tss@hotmail.com</TD></TR></TABLE>

94 EX dizzy
94 EX injectors
94 EX ECU - p28

Timing is good.
Compression is good
94 EX dizzy

Like i said I am getting spark, injectors are spraying fuel....

I wish I could of did the MPFI first than went to OBD1 but the car came to me with a blown motor, and he had bought the EX already with everything.

 

Who made your adapter harness, and how did you wire up the distributor (color to color, or sensor to sensor)?