hi guys, I'm working with a acceleration issue which lead me to a faulty Map or ECU.

disconnect the MAP plug with switch to ON:
1- YEL/RED + GRN/WHT = 5.0v
2- GRN/RED + GRN/WHT = 4.0v

ECU plug D

D17 + D21 = 4.0v MAP disconnected.
D17 + D21 = 1.58v MAP Connected.
D19 + D21 = 5.0 Always.

This seems to be a faulty MAP but I'm a little concern in the fact of the 4.0v instead of 5.0v in D17 + D21.

Any Advice will be appreciate.
Thanks

 

The car in your garage says 97 Civic but your ECU pins are for an OBD1 Civic.

 

yes my car is a 97 ex. The same of my avatar. But it come with a b16 and several plugs spliced with wire crimps. I replaced a few plugs and others still what the car have but soldered them.

 

Oh, And the car have p06 chipped and vtec conversion ECU with obd2a to obd1 harness.

 

Anybody?

 

What engine?

 

Ls vtec turbo
Omni 3 bar MAP sensor

 

When you wrote Grn/Red here^ did you mean Red/Grn?

Swap in a known good ECU to see if both wires now read 5V.

 

Yes sir, RED/GRN. my bad!!

I'm try to borrow a friend ECU.

Ron, It's common when this happen the car don't throw a CEL? If I disconnect the map or any other sensor the CEL come in, also it stay two seconds and turn off when the switch is turn to ON.

 

Aside from lower than expected voltage at the Red/Grn wire, is there any performance issue?

 

Yes, The car when it's cold if I press the gas sputters and die, if left it press.

First time in the morning it have hard cold start.

Once in operating temperature it bogs a little at take off but still drivable.

If you try to make a WOT test it not bog just run like a stock b16.

 

Have you Ohm tested the ECT sensor?

 

Yes, 264ohm at operating temp.

200-400 it's in range?

I have a brand new ECT in the mail for today. The tracking num. say it is out for delivery, as soon as I install it, I post the new reads.

 

Yes

 

New OEM ECT 258 ohms at op. temp. (took forever to warm up rainy day).

Also I no have vacuum pump but:

MAP
1- switch on = 1.58v
2- idle = .53v (22-24 hg)
3- giving throttle and let out 1.34v

 

At the time I not found anybody who borrow me an ECU.

I'm going to pickup a stock MAP on a friend house and see if the 1.58v change close to 3v or stay low.

If stay low it's mean the ECU is bad?
If change close to 3v my map is bad?

 

Do you still have the stock MAP sensor? If so, check the voltage at D17 with the key in ON(II) (engine off)? Does it read 3V?

The low voltage at the Red/Grn wire, however, suggests an ECU problem.

 

Do you have a boost gauge capable of measuring both vacuum and boost pressure. If the problem occurs when cold you may be puddling or flooding the engine when it is cold. Who programmed the ECU?

Did this setup ever run properly before?

 

Yes, the car is turbo since 2010 with different set ups and until 2-3 weeks the car was running flawless.

I have vac/boost gauge.

I checked every set of plugs I've put since the trouble begin and the car isn't getting flood in cold start, also when the car is cold where the sputter and die situation is more noticeable, if I press the gas the wideband instead of going rich it goes out of parameter but to lean.

And not is fuel pressure drop. The pressure is steady at 50psi.
1-new walbro 255lph rewired
2-new fuel filter
3-new AEM FPR
4-new 3/8 feed line from tank to filter
5-cleaned injectors with new seals

My cousin and me tuned our cars, sometimes in the dyno others at the strip.

 

Ron, put the new map sensor and get 2.90v at pin d17 from 1.58v old MAP.

But the car works even worst than before, sputter all the time it's no drivable now.

And still get 4.0v between d17 and d21with the MAP disconnected.

This means definitely my ECU is toast right?

 

Ok, so borrow a chipped pr4 the guy said is good, test the map plug but now receive 2.38v at d17 instead of 4.0v with mine and this is low.

By the way any plug sensor I remove the CEL won't come on in this PR4.

 

You said there were splices everywhere, have those been resolved?

 

that's what I think, but look's like I have an open wire.

I think I'm going to remove all the engine wire harness to repair it complete.