Whats up guys i have a couple of questions. I recently put the car back together ( 00 ej8 with b18c swap) But theres a few issues that are driving me nuts

1. Fuel pump takes A LOT of time to prime on cold start ups , once it warms up it primes a little faster but its still not normal. Now i checked and re-checked the t-housing ground and everything seems to be in good working order.

2.When i shift into 1st and try to get the car rolling (without actually going far , maybe a couple of inches lol ) the rpm's jump at about 1.5k and stay there even if i brake and depress the clutch , a little tap on the gas and then come down to about 900 again.

This is the first time it has done something like this , and its not the first time i've taken the car apart. the car has a tucked harness but i was running this very same harness before without problems , the only thing i did to the harness was delete the 2 junction plugs by soldering the same color wires together.Im not sure if that might be the cause of the problems.

 

Resolder the main relay.

Test resistance to body ground for all of the ECU and main relay ground wires.

If they're all fine, swap in a known good ECU.


Clean the throttle body and adjust the throttle cable so that it has some slack in it.

 

What do you mean by resolder the main relay? I never cut the wires for the main relay.

The trottle does seem to be "sticky" on a cold start but after that it wont stick anymore. What can cause this?

 

http://techauto.awardspace.com/mainrelay.html

 

I did took apart the throttle body and cleaned it , and the throttle body cable has play in it. thats why i find it weird

 

Replaced the main relay and the fuel pump still takes a lot of time to prime. Any other ideas guys?

 

 

What exactly do you mean? Fuel pump runs 35 seconds instead of 2 seconds? The car is just hard to start because it is cold outside????

Has this car exact car/engine/cpu etc worked normal in its current setup? Or did this problem happen after the swap?


If this car/engine/cpu compo worked and you truly mean the fuel pump takes a long time to prime. Put a fuel pressure gauge on your car. Key on/engine off, check fuel pressure and see how long it holds. If it drops right away you have a bad fuel pressure regulator. Start engine and check your fuel pressure. If it is low you have a bad fuel pump.

 

If i put the key switch in the on position , the main relay clicks but if its the first start of the day i have to wait at least 3-4 minutes before i can hear the fuel pump. After that i can start it up just fine but if i let it sit for a couple of hours the same thing happens all over again.

Is there any wires in the engine harness that could be causing this? the car worked fine with the same set up before , same ecu , same engine etc , all i did to the harness was delete the junction plugs like i said earlier.

 

That might be a main relay or it sooo damn cold where you live your fuel pump is having a hard time.

If you know how to read a relay I would just bypass the main relay and jump the fuel pump to see/hear if it will run first thing in the morning. If yes, then probably main relay. If it still takes 3 to 4 minutes for your pump to start then probably your pump is going bad.

 

I just replaced the main relay this afternoon and im in PR coldest temp around here its around 65 degrees lol , im thinking maybe its a wiring , fuel pump or ecu issue , i do have a cell on but its code 10 the IAT.

 

Someone deleted some of my entries. Weird. One of things I said to do was hookup a scanner and check for coolant temp and IAT because the ECU uses those two sensors to figure out home much extra fuel to give it on a cold morning. Probably not your problem because later you said the fuel pump did not even turn on.

Before you replace the ECU I would find a way to apply power/ground to your fuel pump first thing in the morning. Either you bypass your fuel pump relay or go to the actual fuel pump.

I almost never had to replace a ECU. Most be common on Honda. At least on this board seems like every 100th thread is about replacing/swapping an ecu.

Did you ever check your battery?

 

This is a very good idea. I don't think you should Ohm the wires though. Instead do a voltage drop test.

 

is the fuel pump loosing pressure over night and the fuel pump not running for those 2 seconds after a while of the switch being in the on position is the same problem? or those 2 are different issues?

Because like i said , after it starts if i shut the car off and put the ignition in the on position right away i can hear the fuel pump prime for to seconds and the car starts fine , but if i let it sit for a couple of hours/over night , it wont prime after about 3-4 minutes.

 

I am a mechanic but not a Honda expert. (check your manual for your make/model for the specs )


If you hookup a fuel pressure gauge what you will see on most cars when you turn the key on/engine off:
fuel pump primes to about 50 psi Right after the pump primes the fuel pressure might drop 1 to 5 psi and then it should hold for a while. If it drops right away you have a bad fuel pressure regulator.

Find a way to get power ( thick wire I think your fuel pump is 20 amps ) to your fuel pump. Do if first thing in morning when it acts up on you. If you can knock out this test it will help a lot with the rest of the trouble shooting. That will tell if your fuel pump is working.

To test your wires/ecu/relay/fuse: Put a multimeter on the fuel pump. The wires need to be long enough so when you are at the drivers seat you can see if your pump is getting power. Since it only primes for a few seconds before it starts you need to be able see the multimeter while your turning the key on. If you turn the key on, then go back to fuel pump the two second prime might already be over.

 

the fuel pump primes , and the fuel pressure gauge sits around 40psi. Its really kicking me in the head because if the fuel pump was bad it would not turn on at all right?

 

I am confused. It always primes or just right now? I thought you said the fuel pump does not turn on for 3-4 minutes first thing in the morning when the car has not been run.

Fuel pumps some times just die 100%. A lot of times they cause problems like you are seeing. It is a electric motor affected by temp, loose wire/windings etc...

 

If you have any friends that own a chevy tahoe/suburban you can ask them. Those things seem to go out around 60k miles. hahaha.

 

Its not just in the mornings , i turn the switch in the on position and i have to wait for a while before i can hear the pump go on , after that if i shut the car and try and start it right away it starts but if i let it sit for a couple of hours it wont start right away , i have to wait again. not sure if u understand what im trying to say

 

post a video please?

 

Normal behavior:
Key is turned from off to ON(II), at which time the fuel pump runs and CEL illuminates for 2 seconds.

Abnormal behavior observed by OP:
A long delay between turning key to ON(II) and the pump running. I believe that CEL probably remains on steady during the delay and turns off when the pump eventually runs.

Diagnosis:
If the main relay/ECU fuses and the G101 grounds are fine, this problem is typically caused by a bad ECU.

 

Im trying to find another ecu right now so i can swap them and see if theres any difference.

 

That is a Honda guru/god. Sounds like Ron has already seen this a lot.

I have not worked on enough Hondas to have ever need to replace the ecu.

I have only ever replaced ecu because of a TSB.

Unless you can get an ecu for $100 ( that's just my thresh hold of pain ) I would still check your pump (straight power to it). Multimeter to the pump to make sure it is getting power.


I have seen a lot of relays work intermittently/random. In your case though it sounds like you can replicate the problem very easy.

 

I repaired the main relay using the link above and did not work out , so i replaced it and still the same.

 

Get a meter on the fuel pump and check while you are starting the car.

BUT I am guessing Ron must have seen this a hundred times.