Snap didn't realize you're in Tx or I would've driven up there to see whats going on.

 

I think I know what ground wire your tapping but the question is why is the main relay not receiving that signal itself. You're gonna have to trace that wire to where it goes.

 

Additional tests can be done but, given that the pump always primes when pin 7 is grounded, the ECU is almost surely toast, as I already said.

Nothing that you have posted points to the ignition switch as causing the pump not to prime. You should, however, do the tests to see if the no-crank problem is caused by a bad ignition switch.

Again, nothing that you have posted points to the ignition switch as causing the pump not to prime.

Stop paying somebody to repair your ECU. I seriously doubt that all bad ECUs can be diagnosed and repaired. Invest in a known good P28 that comes with a guarantee that it works.

 

"Stop paying somebody to repair your ECU. I seriously doubt that all bad ECUs can be diagnosed and repaired. Invest in a known good P28 that comes with a guarantee that it works. "

This advice really surprises me. My past experience has been that 15-20 year old ECUs would have known issues very similar to the know issue of the 20 year old MFPR (solder connections failing). In the case of the p28 I understood the chip, and or several capacitors would go bad with age & this was a routine repair. My car is bone stock (with the exception of a starter button). I have a post looking for a known good P28. Does anyone know of a source for non chipped (stock) p28s ??

 

Your surprise comes from the fact that you have much more confidence in the idea of "ECU diagnosis and repair" than I do. I believe the ability to diagnose and repair bad ECUs is limited.

 

"I think I know what ground wire your tapping but the question is why is the main relay not receiving that signal itself. You're gonna have to trace that wire to where it goes."

I agree for the long term fix BUT that's Not The Question, This is the question:

"Can I bypass my ignition switch to manually energize my main fuel pump relay to turn on my fuel pump so I can get the dang car out of my driveway?? I need to run it 60 miles up the road where it can sit until I got the issue under raps.

IF YES, What would be the best way?? Run a switched ground wire to pin 7's wire at the ECU ??? This will turn on the fuel pump for sure.

ANY THOUGHTS ?? Thanks Harley "

 

You would have a much better idea on the subject than I. My experience is very limited on this issue. Like clockwork, at year 15, a 300 lexis ECU will start dumping fuel in cyc 3&5 in scary amounts (raw gasoline dripping from the tail pipe). Pulled the ECU sent it off to be repaired 7 years ago & it is still working just fine.

 

I don't want to leave you with the impression that I think Honda ECU repair is impossible. Clearly, in some cases, a bad ECU can be repaired. What I'm saying is that I don't believe that all or even most bad ECUs can be diagnosed or repaired.

With this said, it's possible your ECU could be repaired. This is worth pursuing if your previous ECU repair was warrantied. Otherwise, I would be skeptical about a company telling you that they can definitely fix any bad ECU for a fee.

 

Any ideas where to find good stock P28 ECUs ??

 

I've got a P28 in the mail headed this way...I'll post what happens next.. If this corrects the issue I'll be looking for a spare, so if you have one you are willing to part with send me a PM. Thanks for all the help. Harley

 

Why did you send it in in the first place and what was the turn around timeframe on the the rebuilt ecu and how much did they charge? I don't even think its worth it to "rebuild" an ecu because alot can go wrong and only a pro with circuitry knowledge, PLUS the original honda schematic of the ecu itself will be able to repair the ecu. This task is not easy and requires time to look over the entire circuit.

 

If you say grounding pin 7 sends power to the fuel pump and you're able to make the car run than by all means ground it, but its not something i would do because thats actually a security issue. You're setting your del sol up to be stolen. Good luck.

 

"Can I bypass my ignition switch to manually energize my main fuel pump relay to turn on my fuel pump so I can get the dang car out of my driveway?? I need to run it 60 miles up the road where it can sit until I got the issue under raps.

IF YES, What would be the best way?? Run a switched ground wire to pin 7's wire at the ECU ??? This will turn on the fuel pump for sure."

This is a question ( that I've asked 3 times w/o an answer), not a statement.

I sent in my ECU because my car would not start after replacing the MFP Relay & as far as I know it's the original 20+Y/O ECU. Paid $75 + potage, took about a week or so turnaround.

 

Your fuse may also be loose for your fuel pump under the hood. It happens to the one for my radio...Make sure it's in all the way...I would actually replace it if you haven't...I think its a 15amp fuse....sometimes the simple things we over look like a bad ground or a blown fuse will fix the problem.

 

AN UPDATE ON MY WOE : Yesterday got the different ECU, Plugged it in and SHAZAM just like when I cleaned the ground the car fired right up !!! This is after 2 days with a totally dead pump & over a 100 tries, including 4 or 5 just before switching ECUs. Plugged in the different ECU & BANG the Pump immediately came on & all was well. Started her up 10-15 times ran a few errands & OF COURSE buttoned up everything BECAUSE I WAS SURE ALL WAS WELL !! Well this morning (just overnight) went to move the car and WTF, just like before NO FUEL PUMP = NO START !! I mean DANG this deal has really got my goat. While running around yesterday I toped her off with 4gals of high test, noticing the last fill up was the end of July 2013 !!! What the heck could be going on at night ??? When I do get her to run, Runs well, runs for hours, starts on & off 10-15 times at least. THEN the next morning It's back to square 1 , for at least 5 or 6 times now!

 

It must be losing continuity somewhere. This is where you just need to get technical with a meter man. Might wanna look into replacing the ignition switch, I don't mean the whole column and key. Also look at the starter cut relay as well. Your starting issue reminds me of my sisters integra where it would start fine and then out of no where it wouldn't start at all. Changed out the ignition switch and all was good. I have not heard back from her, thank god......

 

SO my testing shows at this point if I want to drive the car every other day I should be good !! You guessed it, this morning the fuel pump fired on the 1st try & I'm guessing I'll get to drive all day if the past is any indication. A VERY GOOD POINT is the car has never stuck me anywhere except my drive way !!

 

I think that is a good call Tony: Can I get help in lining out the path from the key to the fuel pump? Ever since I cleaned the ground, if the fuel pump runs the car starts right up.
QUESTIONS
1) procedure to get to the ign switch?(steering columns tend to be tricky in my experience)

2) any contacts, fuses to clean, or anything else to check in relation to having the fuel pump energized upon turning the key to ON II ??

3) are there any test procedures that would give more insight ? And if so, is it correct to assume that the "NO FUEL PUMP" condition has to be in play to get a correct or true test ??

 

As per request:

 

The only way the fuel pump is going to prime is if it gets a signal from the ignition harness, think about it. The page I posted with instructions on how to test the main relay shows it needs a signal from the ignition. This is the only conclusion I can come to is that something is iffy with the ignition switch.

 

I think that is a good call Tony: Can I get help in lining out the path from the key to the fuel pump? Ever since I cleaned the ground, if the fuel pump runs the car starts right up.
QUESTIONS
1) procedure to get to the ign switch?(steering columns tend to be tricky in my experience)

2) any contacts, fuses to clean, or anything else to check in relation to having the fuel pump energized upon turning the key to ON II ??

3) are there any test procedures that would give more insight ? And if so, is it correct to assume that the "NO FUEL PUMP" condition has to be in play to get a correct or true test ??

 

"Can I bypass my ignition switch to manually energize my main fuel pump relay to turn on my fuel pump so I can get the dang car out of my driveway?? I need to run it 60 miles up the road where it can sit until I got the issue under raps.

IF YES, What would be the best way?? Run a switched ground wire to pin 7's wire at the ECU ??? This will turn on the fuel pump for sure."

This is a question ( that I've asked 5 times w/o an answer), not a statement.

 

After all of this, there is two things that come to mind that I'm not sure have been discussed.

You tried two ECU's and the second ECU worked initially then started acting the same as the original. Do you know if all the signals going to the ECU are in good order? Could there be a short that is straining and even possibly killing ECU's with use?

The other thought is the fuel pump... I will admit, I really hastily skimmed through the three pages of thread so could have missed it but.... Have you done any testing of the fuel pump? Could it be sticking, it always gets the signal but sometimes can't break free to pump and sometimes can?

I will hazard a guess that folks are avoiding the bypass question being it's not a proper fix.

Just like anything you could bypass the systems by just finding out what voltage and what current are required for the pump (fan, light, etc). Then run wire from the battery to your custom built voltage regulator circuit then to the item you want power.

The other area you may have to be concerned with is whether or not any of the other systems need feedback from the item you are "hot wiring". If they do you have to emulate that feedback.

However, that is a really hokey way of going about things. I mean you say it is so you can put it up the road to where it can sit until fixed, yet you say it runs every other day so you could have driven it there at any time and left it to be worked on.

I may have missed some bits, I did only skim through the three pages but I am willing to bet that these thoughts might be pretty close to some other members as to why they would be dodging the bypass question religiously.

 

You tried two ECU's and the second ECU worked initially then started acting the same as the original. Do you know if all the signals going to the ECU are in good order? Could there be a short that is straining and even possibly killing ECU's with use?

(ECU acted the same the next Morn, Not much use, If ECU is dead how does it run so perfectly if the F/P will prime?? No I do not, That is what I'm hoping to get help with.)


The other thought is the fuel pump... I will admit, I really hastily skimmed through the three pages of thread so could have missed it but.... Have you done any testing of the fuel pump? Could it be sticking, it always gets the signal but sometimes can't break free to pump and sometimes can?

(F/P is new & works every time the ECU pin was jumped to ground)


However, that is a really hokey way of going about things. I mean you say it is so you can put it up the road to where it can sit until fixed, yet you say it runs every other day so you could have driven it there at any time and left it to be worked on.

( Car is moved, 60Miles (needed to start at a time I could get a ride back) drove great, still need to fix it.. )

There is no rime or reason as to when it will or will not prime that I have found. I am believing it is the Ing switch at this point & looking for help to check, clean, or replace the switch or fuses, connectors, wires or anything someone can think of from the key to the M/Relay or ECU. Thanks

 

I'm assuming you have the D16Z6 motor from your earlier posts. So since you are still having issues and you are confident your mechanical and ignition timing is correct (by running well when it starts). I will post the pages pertaining to the No Start diagnostic. This first one is #1 in the list to diagnose for No Start, the ECU.







More to come.