Need help! No WOT falls on face.

[minimoose]

Hi. To start off my car will not go wot. If you slowly rev the engine you can get it to 7k but if you floor it it starts spitting and sputtering. I have replaced the tps sensor with a brand new in the package sensor and cut the bell housing off my sending unit and ran a piece of fuel hose from the pump to the sending housing instead of using the o ring. Car is running very rich and I am lost on what to do next im tired of guessing. Im hoping someone can help me out i have had this car 2 months and never driven it anywhere.

 

[boosted99_420]

try your fuel filter and/or injectors

 

[minimoose]

If the fuel filter was bad wouldnt it cause my pressure to be bad tho? I have multiple sets of injectors so ill try that again.

 

[6A12TT-7G]

Do you have AFM or MAP? From what you say the ECU isn't registering accurate airflow and either leans or floods depending on what it thinks it needs to do causing the misfire.

A small amount of throttle position most likely won't upset the metering enough and will give you a relatively smooth rev. But opening to WOT with an AFM only reading say 20-50% while at 100% airflow will screw up your stoich ratio causing misfires.

 

[minimoose]

I dont know what those look like or are. if its an aftermarket thing all I have is an apexi safc2 and a palm style datalogger. Sounds like you are on the right track tho and I would really appretiate any more info or help you can offer!

 

[steve]

Ah, in context, our friend from Australia is asking you to check your MAF if the air flow metering is stock or your MAP sensor if it's been converted to Speed Density.

When was the last time you checked for boost leaks?
What fuel pressure are you running?
What settings on your SAFC?

 

[minimoose]

Boost leak test is in process. Just over 30lbs on pressure for fuel. Afc2 is set to 0 , throttle is set to 10 and 40 I think.

Yea maf does nothing when I unplug it while the car is running, no change so im assuming its bad. Wouldnt a bad maf make the car idle like crap tho?

 

[steve]

Set the fuel pressure to 37 psi with the vacuum hose off and plugged. Make sure it tracks changes 1:1 in pressure applied to the AFR nipple. It should drop to about 27 psi under normal idle vacuum and rise under boost.

Make sure the CAS is set to 5* BTDC and that your crank pulley is still correctly indicating TDC when your at TDC.

Set SAFC throttle break points to 20% and 80% not that it matters much if both high and low setting are zeroed out. Check the MAF Hz on the SAFC. It will tell you if it's working.

 

[minimoose]

Thanks alot steve ima try it out and ill get back to you!

While im at it whats the plug on the same wire set that the maf plug is on. Its the little 2 wire plug, Mines not pluged in no idea where it goes.

 

[steve]

TWhile im at it whats the plug on the same wire set that the maf plug is on. Its the little 2 wire plug, Mines not pluged in no idea where it goes.

I think it's for the boost control solenoid. You want to make sure water can't get into it.

Which also raises the question of how much boost are you trying to run.

 

[minimoose]

Im trying to run stock right now have the mbc but its set to stock just blow through. I set the fuel pressure to under 40 with the vac line removed. still runs like crap super rich. How do I check the maf with the apexi safc? I tried figuring it out and Im lost.

Im guessing from reading the apexi book the maf signal would have to be the afl, They call it airflow (hot wire/flap) usage ratio.

Ok so I check the afl for my maf. and it moves but stays flat on the bottom of the screen. When you rev it it moves left to right, but not up and down. anyone know if this is normal or? Thanks for any replys im watching this board trying to get my car fixed today so ill have fast replys.

 

[steve]

Im trying to run stock right now have the mbc but its set to stock just blow through.
How do I check the maf with the apexi safc? I tried figuring it out and Im lost.

Im guessing from reading the apexi book the maf signal would have to be the afl, They call it airflow (hot wire/flap) usage ratio.

It's Karmen for our MAF, not hot wire, pressure or flap. Make sure your sensor type is set to Karmen.

Your comment on the MBC being blow through confuses me.

 

[minimoose]

My sensor im pretty sure is set to karman. Ill check that. By blow through I ment it does nothing, theres no added pressure resistance it just flows through with no resistance so it doesnt cause the car to build higher boost to move the ball out of the way inside the mbc. Thanks for all the help steve I really appretiate it! going to check the karman sensor and ill be back in 2 seconds to let you know.

Ok sensor is / was set at karman. Watching the karman sensor signal it also stays flat and moves from side to side only on the bottom of the chart.

I bought a 2g Maf Have the plug and was going to throw it on the car hope it did something other than piss me off.

Huzahh! Ok I feel somewhat better and dont want to burn my car to the ground. While playing with my plam pre data logger I came across my cel's which are > 12 ( mafs ) 13 ( air temp sensor )and 14 ( TPS ). Now i know for sure the tps should be good I bought it brand new unopened in the package. The maf im unsure I have watched it on the safc but thats all I can see. I try deleting the cel's and they instanly come back. Anyone have anykind of imput?

 

[steve]

If you get a baro CEL too I'd be sure of a blown sensor ground on the ECU. May still be.

 

[minimoose]

I dont get what your trying to say with a baro cel. I am going to throw my 2g maf on in the morning and if that doesnt fix it you think its a bad ecu?

 

[steve]

There are three sensors in the MAF, airflow, air temp, and air pressure. Those plus the TPS tend to pop up CELs together when the ECU sensor ground is blown.

 

[minimoose]

Im glad you know alot its really helping. So what do you think is wrong my ecu is bad?

Does the ecu ground through the case? My ecu is just sitting on the floor right now.

Ok I took the ecu out of the car and shure enough the ecu had a very tiny burn / brown mark in one line on the bottom of the board. From the top its right under the C108 pin number marked on the ecu from the top. It is very small but the whole line its on is " burned/ poped" whatever you want to call it. Where can I take this to have it fixed that would be close to me? I live in bradley ill. Or should I get a new ecu. Im looking at a 90 awd eprom I found for sale for 150. Also when I put my new ecu in does it have to be bolted down, does the ecu ground through the case to the frame, or can I let it sit loose. Thanks alot everyone aka Steve.

I tried getting pics but my cameras not cooperating.

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I have the picture on my facebook but I cant get it to load on the website here.

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Heres a pic of the burn. If the photo loads....

 

[steve]

The ECU grounds via the wiring harness.
I tried to find your facebook page to see the damage but failed.

 

[minimoose]

Just type my name in. Its Steven Timbs the pic is posted in my page not my pics. Theres a very tiny bun in the shape of a circle, super small but take a whole line where it is. I scratched the bun away gently with my finger and its all the way through the single line, but you cant see it from the top of the board.

Im Buying a used eprom ecu for a 90 ecu just happend to be for sale close by looking it over tomorrow and putting it in ill let everyone know How it goes.

The burn mark is in the middle of the board and is on a tiny light green line.

 

[steve]

It looks like I have to friend you to see the picture. Sorry.
You don't want to put another ECU in the car until you have identified what happened or you run the chance of damaging that one too.

 

[minimoose]

Im pretty sure I know what did it. When I got the car about 2 months ago it was took apart and non running had been sitting for a long time. I had to pull the fuel pump and replace it because it was not working. When I pulled it out I noticed some moron had soldered the power wire in the middle of the wire, not to the pump , and taped it. The gas ate the tape and there were a bunch of black ark marks in the tank and alot of the fuses in the fuse block were replaced with 10am higher than they were supposed to be. All the fuses are back to the stock amp and I replaced the bad wire. I havent come across anything eles that would have done anything to the ecu. My new 90 eprom is on its way to my house right now so when it gets here I'll throw it in and see what happens. If it breaks it also I'll get it fixed and start looking for another problem.

 

[steve]

Normally the ECU is isolated by the MPI relay from the fuel pump so that doesn't sound very likely as the cause.

Your description is confusing. Are you sure that the burned trace your talking about isn't under C106, the capacitor in the middle close to the edge connector? If so that's likely caused by C106 leaking.

 

[minimoose]

Nope was the c108 on the bottom of the ecu, board is super clean just one small burn no leaking caps. Just got and put in the eprom ecu and starts runs fine. Now its only throwing the maf code. I have a 2g maf I was going to throw on anyway.

Car runs great the only probelm Im having now is when you come to a stop fast it dies, which im assuming has something to do with the maf. The maf code doesnt pop up right away takes like 15 20 seconds after starting. Im going to do the 2g swap and see if that helps. other than that the only probel / things I have to fix right now are new brake pads and the oil pressure plug on the acorn shaped ... thing .. is loose and falls off then the guage stops working but that should be an easy fix. Thanks again steve, your my car hero...

 

[minimoose]

HMMM confused as to whats wrong now unless new ecu was bad also from leaking caps. The ecu def has leaking caps you can see it, But the cars runs and drives but when you stop fast it dies. Also the maf cel always comes up even when the car is off so im lost. 2g maf is hooked up correctly, Can tell its getting more air. Any ideas? The maf Cel is the only cel that comes up now. Im going to try another 2g maf maby the one I bought was bad, buddy has a good 2g maf.