This afternoon I was trying to diagnose a code 43 (fuel system) on my ls/vtec (b18b block, jdm b16 head, chipped p28 ECU in 99 Integra RS). I stupidly opened up the ECU to do the voltage checks from Honda's troubleshooting flowchart rather than just probing the connections from the outside . I accidently made a connection between some wrong pins and saw a spark.

After putting everything back together the engine turns over but will not start. I went to reset the ECU by pulling the FI E/M fuse in the engine bay fuse box and realized it was blown (Could have already been blown) . I replaced it and engine still turned over but didn't start. I then realized I still have my original OBDII ECU, plugged it in and had the same problem.

I am not getting spark with either ECU and when I jump the code checker it is just showing a solid check engine light with both ECUs. What the deuce is going on?

 

It might be a burnt fuse i believe. Cause if your still using your obd2 ecu and still no spark then i would guess a burnt fuse. Check the fuse in the engine bay and fuze box. Also check the harness plugs that go into the ecu if one of the pins such as the the ignition pin got fried somehow.

 

A P28 ECU/ECM is OBD1.

Shorting out anything inside the ECU/ECM is never good, normally results in damage to the ECU/ECM.

As mentioned, check fuses, maybe you got lucky and all you did was short a 12V+ input to ground, [no load in-between].

If not, you will be replacing the ECU/ECM.

For the OBD 1 trouble code 43, did the fuel pump prime, was there any "clicks" from the PGM-FI Main Relay when ign. switch was turned on? 94

 

Thanks for the suggestions, I will be pulling every fuse to check them tonight, as well as grounds and the main relay.

The OBDI p28 is what I've been running the ls/vtec on but I meant that I have my original OBDII p75 ECU and am having the same problems with it, which is why it may not be the ECU that is the problem. The car used to run (not nicely, but at least ran) with the p75 and now it is having the same issues with both ECUs.

Also, the fuel pump did prime and the car ran fine with CEL 43, I was just trying to get rid of the CEL because I am ocd about them haha. Probably just need a new O2 sensor or FPR. Anyways.... I dont think the CEL 43 is part of the problem. What do you guys think?

 

I checked all the fuses and they were good and sanded the valve cover, tranny and thermostat housing grounds. Checked the main relay and both internal relays are working fine. Just to be safe I re-soldered the connections in it. It is only getting 0.01V when the ignition is switched on. The fuel pump is priming when the ignition is turned on. I also took a look at the ECU pins and inside the ECU and everything looked fine but who knows.

The car also has a viper alarm/remote starter and when I try to start it with the starter it does not even turn over.

 

That was a little confusing...

The fuel pump did prime before you shorted the ECU/ECM or it still primes???

What lead at the PGM-FI Main Relay, "is only getting 0.01V when the ignition is switched on"???

Do you mean when you try starting with the remote start, "when I try to start it with the starter"???

If so, does it still crank, [turn over] with the key? 94

 

The fuel pump did prime before I shorted the the ECU and it still primes.

There were a couple leads only getting 0.01V but it was late last night and I cant remember which ones. Will get back to you on that.

Yes, I mean when I try to start it with the remote start, and yes, it does still crank.

 

So I Bought a new ECU and after recharging my battery I am having the same problem. I am extremely frustrated because I cant find the problem

 

What year is your Integra?

You said the fuel pump still primes, is that correct?

Have you checked for spark?
DO NOT just pull a spark plug lead, either get an HEI spark tester or plug a spark plug into the lead and ground the plug.

Even though the pump primes it does not mean fuel is getting into the cylinders, try starting the engine a few times, then pull a spark plug and inspect the end, is it "wet" with gas, does it smell of gas?

Check for power to the injectors, [lead that is the same color at all 4 injectors] should have power when ign. switch is on.

Check for power on the black/yellow going to the distributor assembly, [ign. switch on.

You should also confirm, IGP1 and IGP2 to the ECU/ECM have power, [ign. switch on], can't give you wire colors without year of car, but in most cases will be the same color as the fuel injector power leads and will be the only two leads that color going to the ECU/ECM.

Let me know what you find.

Also a discription of exactly what happens when you try and start the engine would help, [what lights up on the cluster, how starter cranks, (weak/strong) how long the the fuel pump primes, does CEL go out when pump stops priming and so on]. 94

 

i'll bet $0.01 it's a cooked ICM

 

It is a 99 Integra. The fuel pump does prime. I have checked for spark and there is none (I did it buy pulling the plug and grounding it). I will check for gas and power to the injectors tomorrow, thanks. I found an OBD1 ECU pinout so Ill check the IGP1 and IGP2 as well. Everything lights up on the cluster including the CEL and the CEL does not go out, It displays a solid code 0 at all times. The starter cranks strong for about 5 tries and then I have to give it a boost with my girlfriends car. (Starter is only 6 months old and is a brand new OEM Acura starter)

Today I took the dizzy out and found a ton of corrosion and this sticky liquid on the inside of the cap, which I think was oil mixed with corrosion. So I took the distributor off, bought a new cap and rotor, and cleaned out all the corrosion and stickyness. Still have the same problem.

Solster is there any way to check the ICM?

 

Confirm power to the distributor and IGP1&2, no power to any of the three will result in no spark.

When cranking to start, does the tach "bounce" a little, if so, it is an indication the ICM is good, no "bounce" indicates a bad ICM, [or no power to the distributor assembly].

A solid CEL points to a problem with the ECU/ECM, have you scanned for codes?94

 

IGP1 (which is the power ground) is getting a solid ground however IGP2 which is the power source is not getting any power. I'm going to try and trace the power to the ECU to try and find a problem. The distributor is getting power and the injectors get power when I try to start the engine. I dont have a code scanner, but the CEL stays solid when I jump the passenger side Jack.

 

Both IGP1 and IGP2 are powers, [12V+] when ign. switch is in the run and start position.

Both IGP1 and IGP2 get there power from the fuel injector power relay inside the PGM-FI Main Relay, the fuel pump would not prime if there was no power to IGP1 and IGP2.

Recheck your results, confirm you are probing IGP1&2 pins, [both leads will be the same color].

Also test for power at the injectors, [lead that is the same color at all four injector plugs, and most likely the same color as IGP1&2, yellow/black] confirm all the above have power when the ign. switch is in run and start.

These voltage tests can be done with a 12V test light, [not the LED type].

If no power at any one of them, test for power out of the PGM-FI Main Relay, [fuel injector relay] I am guessing yellow/black, again, test with the ign. switch in both the run and start positions. 94

 

Hey Guys, turns out i'm a complete idiot. After figuring out the black/yellow wire from the pgm f/i relay was getting no voltage I rechecked my fuses and realized that there was no fuse in the 15 amp fuel pump spot under the dash. When I first saw the 15 amp pgm f/i fuse was burnt out under the hood I accidentally took the fuel pump fuse to replace it instead of the spare fuse. I thought that I had been hearing the fuel pump priming but i think it was actually something in the head unit making noise.

Thanks for all your help!

Btw, anyone want to buy a chipped p28? haha

 

Sometimes it's the simplest things. 94