4g63 swapp/diagnosing questions

mitsuman · Post by **mitsuman** » Mon Jan 08, 2007 9:34 pm

did the 4g63 swapp. having trouble with the engine. it falls on its face when you give it gas. i have spark and fuel. checked for vaccume leaks.none found. has brand new computer. just got it today. thinking that was the problem becaues i swapped most all of the sensors on the engine. it is not the cam angle sensor, tps.coil.vacume.fuel or spark it is hard to start like a big vacume leak but i went around the hole engine with gum cutter found nothing.the only things i didnt try was fuel injectors and iac.or o2sens. i dont think iac could do that. seems to be running rich also u checked wires on harness side and sensor side. all checks ok. i have good compression and timming is correct. i know becuse i rebuilt the engine my self. the most it ran was idling in my garage.oh and it idles good. anyone who figures this out is a freaking genious. so if you have any suggestions or ideas. please let me know . thanks greg

jeffball610 · Post by **jeffball610** » Mon Jan 08, 2007 9:46 pm

It does sound like it's running rich. Might have a vacuum leak. Do a boost leak check. I believe VFAQ has directions on it in the intake section. Do you have a datalogger? That's the best and cheapest tool you can have. Plugs into the diagnostic port (hopefully you have that with your harness) and the software for Palm is free. Search for MMCD. That's the software. Cables can be had on eBay and other sources. This is a 1G right? Other than that, you might have the MAS hooked up wrong. I forgot to plug mine in once and it idled fine, but died when you tried to rev it. Let us know what you find out.

91turboGSX · Post by **91turboGSX** » Mon Jan 08, 2007 9:53 pm

Kinda sounds like the MAF to me...

mitsuman · Post by **mitsuman** » Mon Jan 08, 2007 9:57 pm

nope not the maf.

mitsuman · Post by **mitsuman** » Mon Jan 08, 2007 10:00 pm

i think i will try a boost check though . but i do not have a datalogger

screemin eagle · Post by **screemin eagle** » Tue Jan 09, 2007 11:12 am

WHAT INJECTORS ARE YOU USING? IF YOU HAVE THE STOCK MANUAL INJECTORS THEY ARE 450'S AND A AT COMPUTER THE RUN 360'S WILL CUASE YOU TO HAVE ISSUE THAT YOU ARE DESCRIBING

peregrine · Post by **peregrine** » Tue Jan 09, 2007 2:35 pm

91turboGSX wrote:Kinda sounds like the MAF to me...

thats what i was thinking. if its not getting a signal from the maf it will run in limp mode and do exactly what your describing.

carguyf545 · Post by **carguyf545** » Wed Jan 10, 2007 7:41 pm

my escort has a maf. and that is what it does if i comes slightly unpluged. but if it is unpluged all the way the car will not run. you say its not that, the only thing i can think is the tps. hope that helps

mitsuman · Post by **mitsuman** » Sun Jan 14, 2007 12:50 am

OK. IT IS DEFINETLY NOT THE BOV. I HAVE BLOCKED IT OFF MORE THAN ONCE. AND IT IS DEFINETLY NOT THE MAF.SENSOR. I TESTED IT WITH MULTIMETER AND ASLO TESTED HARNESS SIDE VOLTAGE GROUNDS AND RESISTANCE. ALSO TESTED TPS THE SAME WAY. AND TESTED THE COIL. IT IS ALSO NOT LOSING SPARK, SO ITS OK. AND IT IS DEFINETLY NOT THE ECU. IT IS NEW. I TESTED POWER AND GROUNDS AND ALL THE SENSORS ARE GETTING CORRECT VOLTAGE FROM ECU. I SWAPPED THE INJECTORS AND IT DID NOT CHANGE A DAM THING! I ALSO HAVE CORRECT FUEL PRESSURE. ALSO JUST SWAPPED CAMSHAFT POSITION SESOR AND THATS NOT IT. CHECKED FOR VACUME LEAKS AGAIN AND FOUND NOTHING. AND PERFORMED BOOST PRESSUER TEST FOUND NOTHING. I THINK I MIHGT HAVE FOUND ONE THING THOUHG. I PUT MY NOID TESTER ON THE INJECTORS AND TOUCHED THE GAS AND MY NOID TESTER LIGHT GOES OUT INSTANTLY. THE QUESTION IS IF IT IS GOING OUT JUST BECAUSE THE ENGINE IS STALLING OR IS IT CAUSING THE ENGINE TO STALL.? I KNOW THE CAM ANGLE SENSOR AND THE CRANK POSITION SENSOR IS IN ONE AND THAT THE CRANK SENSOR SENDS SIGNAL TO THE ECU WITCH THEN SEND INJECTOR PULS TO INJECTORS. BUT I JUST DONT GET IT. I ELIMINATED PRITTY MUCH ECVERYTHING TO DO WITH INJECTOR PULSE. ECU, CAS.INJECTORS. AND WIRING. IF ANYONE CAN HELP. PLEASE FEEL FREE TO LET ME KNOW. IS THERE SOMETHING IM MISSING?

91turboGSX · Post by **91turboGSX** » Sun Jan 14, 2007 11:32 am

screemin eagle wrote:WHAT INJECTORS ARE YOU USING? IF YOU HAVE THE STOCK MANUAL INJECTORS THEY ARE 450'S AND A AUTOMATIC COMPUTER THAT RUNS 360'S WILL CAUSE YOU TO HAVE ISSUE THAT YOU ARE DESCRIBING

Did you look into this man's statement? You sure the ECU is paired with your injector setup? Also when you say new ECU is it actually brand new or just new to you?

Did you also check all the voltages of the sensors with the engine running and while you try to give it gas? I'd suggest investing in a datalogger.

mitsuman · Post by **mitsuman** » Sun Jan 14, 2007 12:55 pm

IT IS BRAND NEW REMANUFACTURED. 1991 EPROM ECU. FOR 5 SPEED MANUAL AND I AM USING 450CC INJECTORS. ALSO JUST TRIED THE 360CC INJECTORS THAT I SWAPPED FROM A FREINDS CAR.

Old Colt · Post by **Old Colt** » Tue Jan 16, 2007 8:34 am

IT IS BRAND NEW REMANUFACTURED

Why do you need to yell so much?

Have you tried another ecu, the last thing I would trust is a rebuilt ecu.
I would trust a used ECU before one that was proven to be bad in the first place.
If you did try one and I did not read it, my mistake, I don't read all caps.

With a good ECU injector size is not important. I run the EVO 510 and 560 cc injectors with stock MAF and ECU. 4Cars now say it is not an issue, Most Mitsu ECUs have quite a wide range that they will compensate for.

richb · Post by **richb** » Wed Jan 17, 2007 7:09 pm

This might be out of place here, but I had the same problem awhile back on a '82 Chevy 350. It turned out to be a collapsed muffler. Replaced it and all was well.

Rich

mitsuman · Post by **mitsuman** » Sat Jan 20, 2007 12:39 am

thats how i been checking my wires to all my sensors so far. also have been checking the 5v refrence 12v and grounds from ecu to all sensors. so far i did this to the maf. tps. iac. coil pack and injectors. the only thing i did not check was the cas. because it is hard to get to that connector. i have it burred under the intake. but i swapped it and it made no difference and you can tell it is working when you adjust it so i dont think i have a problem there. the only thing i found is my injectors are not pulsing. also i have no cat or muffler on it so that can't be it. i also dont think that it is the new reman ecu becaues when i had my old ecu it did the same thing. that would mean i would have 2 ecus with the exact same problem. i don't think that is it either. if someone could tell me were to exactly put the wires for the diagnostic port that would help alot. but now im out of ideas for now!

sorry about the cap lock thing. i was just to lazy to turn them off. i was not yelling!!!!.

Bill Hincher · Post by **Bill Hincher** » Sat Jan 20, 2007 10:06 am

Mitsman,
Calm down, take a deep breath have another cup of coffee.
Cars with trouble makes us better mechanic's

First, this is a swap, did the car set a long time? does it have old gas? I have even had people put fuel oil in by mistake, test your fuel.

Second, you say you have no injector pulse, car can't run with out it, so there is your problem.

Choice of tools and how to use them

Digital volt ohmeters are tricky to use, NEVER measure resisitance with a digital DVOM always use an old fashion Radio Shack $29.95 anolog meter, reason? the anolog uses a battery to push voltage accross the wire to measure the resitstance and gives you the proper information.
When you measure resistance in a wire you MUST disconnect the input or output sensor involved because it confuses the reading by including the sensors information to the meter.

Digital meters read the 'load' on the system you are checking, its not providing voltage to collect information, its seeing how hard that system is working but not telling you why, it includes all the information in that curciut into one number.
After you test the wires alone for resistance problems, then you plug in the sensor and ECU to test with a Digital volt meter.
You say you have no injector pulse, and you know your resistor is good, a resistor is just a shock absorber, it absorbs heat that would normally be generated by the injector itself, if you measure the voltage at the injector with a resistor ( key on/engine off) with a Digital meter it will lie to you, it will say 12v but if you use the analog meter it will tell you true voltage 6v. ( just proves my point)

Got a dwell meter? a $20.00 8 cyl/6cyl/4cyl dwell meter used to set ingnition points in 1966 Fords? works great to test injectors.
Find if you have proper voltage at one side of injector, install dwell meter input on the other side of the injector connector 8cyl,6cyl,4cyl it dont matter, all you are looking for is if the transistor in the ECU is driving the injector ( pulse). now start the car, set you dwell meter where you can get the best reading, the number wont matter ,its just saying the injector is recieving the output from the ECU.

this is how to run a voltage drop test using a DVOM for the entire injector curcuit

this diagram explains why you see no voltage at the injector

and this diagram shows how it can look like you have power on both sides of the injector, causing even more confusion

Timing, timing,timing, you gotta have proper timing
Put a compression gauge in number one cylinder, hook up a timing light to number one ignition wire, take off cam belt timing cover. Mark your cam timing marks with chalk and get a friend ( tough job there)
have friend BUMP starter while you are holding the timing light AIMED at the compression guage, hold your finger lightly over the valve in the compression guage, bump starter several times while holding your timing light aimed at your compression gauge.
Notice your light flashes just before the needle on the compression guage bounces? That proves you have spark, you have spark when you need it ( according to the compression guage) and you have compression.
How much compression you have tells you if your cams are in time, low compression means the valves are too late or too early. So now you know you have compression, spark, and ignition timing, now test your cam timing with the timing light, have friend SPIN car over while you hold light on cam gears, see if your marks line up.
If all these things prove ok, then you have a breakdown in insulation, cracked coil tower, bad ignition wires. to prove that, you must disconnect a spark plug wire and dampen the secondary ignition system,Voltage is just like water, if it can't flow down the stream, it backs up to the weakest dam area. have friend SPIN motor, see any sparks? that is the weakest part of the system, voltage is leaking past the insulation there and causing problems.

Be careful ! fuel with open spark equals fire! Above all be careful
test your fuel pressure for 40lbs but when spinning/bumping the engine, take out the fuel pump fuse, do NOT get HURT/BURNED.
Complicated Bill

4g63mightymax · Post by **4g63mightymax** » Thu Jan 25, 2007 9:14 pm

Mitsuman, any updates on this issue? I would certainly like to hear to outcome if you figured it out.
Also how is there an identical post in the electrical section of this forum?? I think there is.
-Jeremy

Bill Hincher · Post by **Bill Hincher** » Mon Jan 29, 2007 11:06 am

have you run a really good ground wire from the engine to the frame?

run two or three ground wires and you would be amazed at the difference

mitsuman · Post by **mitsuman** » Fri Feb 02, 2007 1:52 am

sorry so late to reply. but no. i do not have any updates yet. i kinda had to put my car on hold for awhile because i have a kid on the way (boy) and my crazy pregnat wife seems to think i need to remodle the baby room instead of working on my car. and everyone knows you don't want to piss off a pregnat women. so you might not hear from me for awhile. but i will definetly update when i start on it again. and will still be watching if anyone has anymore ideas. thanks for all the help so far!!!

tonydanzah · Post by **tonydanzah** » Sun Feb 04, 2007 7:03 pm

you said you had fuel pressure, but have you do a flow test on the fuel pump? a restricted fuel system will show fuel pressure but the second you step on the gas and you do not have enough flow the engine will stumble.

Adlem6 · Post by **Adlem6** » Wed Feb 28, 2007 6:23 pm

Anal sex is better anyway!
http://I-Love-Anal.info/videos/mediapla ... ile=369031

Post by **DJpowerHaus** » Wed Feb 28, 2007 8:06 pm

I dunno.. its a toss up.

Post by **DJpowerHaus** » Wed Feb 28, 2007 8:20 pm

Moments later I realized that this was a spammer bot.. funny how I found this to be perfectly within the context of this thread. How's your wife doing anyways?

Bill Hincher · Post by **Bill Hincher** » Wed Feb 28, 2007 9:09 pm

how was the video,DJ?

Post by **DJpowerHaus** » Wed Feb 28, 2007 9:42 pm

I dunno.. didnt load. What a let down.

77amc · Post by **77amc** » Tue Nov 06, 2007 12:23 am

After my first boy it was easier to take care of him rather than her..
She would just sit there and cry because her tummy didn't go down that quickly.. (It just took her 6months to get back to size)
Got her some good meds forthe next one.

What about the TPS?

Just my 2 cents... errol

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