Starting Funky

[StManTiS]

Basically the car wasn't getting spark, so thanks to some help from the community here it was traced to an ECU. From the classifieds i got a new eprom ECU for the 90 AWD.

Now the car starts but dies unless i keep the gas (air) above 1k rpm. I've revved it to 6k and its more or less fine. The whole car sorta shakes/rumbles at 1000 to 1300 RPM. The whole thing smells of lawnmower gasoline.

A little background: The previous owner had it just sitting for about 5 months or so without starting it. I am going to do a complete oil/fluids change soon. The fuel is probably that old too.

On visual inspection i found both the engine cover valves (PCV and the other) to missing their hoses.

It would be my guess (however inexpert) that only some of the cylinders are working or the lack of PCV hose it cause vac problems.

What could be the problem? Any Suggestion?

 

[StManTiS]

Did you reattach the throttle body ground when swapping the TB?
Set the BISS? What's the TPS voltage at idle? Is the IPS working?

ground is attached, BISS is all the way unscrewed again.
TPS voltage not measured because it Doesn't idle...thats the problem
IPS being the little button that gets pressed when the TB closes?

I was talking to my aunt and she said she had a similar problem with her Renault and that it was caused by dirty injectors or something like that.

 

[steve]

ground is attached, BISS is all the way unscrewed again.
TPS voltage not measured because it Doesn't idle...thats the problem
IPS being the little button that gets pressed when the TB closes?

The BISS being unscrewed indicates a problem with the idle bypasses. That could be a non-functioning ISC, FIAV, or BISS. Was RTV ever used with or instead of a gasket?

The car doesn't need to run to set the TPS. It just needs the ECU turned on.
The IPS is the sensor on the back side of the throttle body that you describe. With the ECU on it should ground the green wire and you should see close to zero volts when the throttle is closed and 5v or more when the throttle is slightly opened.

 

[jeremylee_7]

stManTis, if you need a logger cable give me a pm, i have dsmlink now so i dont need that logger cable anymore.

Sounds more like an ecu/sensor problem then a fuel problem, but would still put a bottle of redline injector cleaner in it

 

[steve]

Also what color are the stock injectors on a DSM? mine are a clear turquoise kind of blue.

My 1G 450's look like this.

 

[StManTiS]

Alright so today i was going through the checklist again. I chekced every fuse and found my alternator blown and the fuse for it as well.
New Alt:

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New Fuse:

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I also triple checked the coil wiring:

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new FPR:

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New gaskets for TB and elbow:

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Also i wanted to make sure...is my coil pack wired right?

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So after all that i took a video of the problem, because it was still there. (Note that the O2 gauge doesn't read out anything even though i tapped into the right wire in passenger foot well) The top gauge (not lit) is the boost gauge. It shows a health vacuum at startup and it "T"ed into my FPR line. The final start you may see it waver, that it because i gave it a little gas that run.

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Interestingly enough in that video, i started immediately after it died without killing accessory power and it started at a normal RPM, but then also died. (sadly there is not sound but of the key turning)

 

[steve]

Interesting, on a stock ECU the factory boost gauge should go to zero when you turn the ignition on, drop to -7 wile cranking and idling, then back to zero if it dies. Yours never seems to. Are you running DSMLink or a chip that might display something else?

 

[StManTiS]

Interesting, on a stock ECU the factory boost gauge should go to zero when you turn the ignition on, drop to -7 wile cranking and idling, then back to zero if it dies. Yours never seems to. Are you running DSMLink or a chip that might display something else?

Here is a picture of the ECU as it came shipped to me from a forum member:

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[steve]

That answers that question. It's got a DSMChip set up to display knock.
Your earlier pictures showed a 1G MAF. Are you running 650cc injectors and a GM MAF with the translator now?

 

[StManTiS]

That answers that question. It's got a DSMChip set up to display knock.
Your earlier pictures showed a 1G MAF. Are you running 650cc injectors and a GM MAF with the translator now?

no..im running stock MAF and stock injectors..i literally just realized that i HAVE a chip that ISN'T stock.

so how would I get a stock map on my ECU? Just find a place to buy the right chip?

 

[steve]

Correct. The chips Keydiver makes for MAFT have the IAT and Baro locked so you can use those inputs for other sensors, which means you can't use it with a stock MAF. Between that and the 20%+ change in the injectors I wouldn't be too surprised that it doesn't run long.

 

[StManTiS]

Correct. The chips Keydiver makes for MAFT have the IAT and Baro locked so you can use those inputs for other sensors, which means you can't use it with a stock MAF. Between that and the 20%+ change in the injectors I wouldn't be too surprised that it doesn't run long.

alright lets hope this is problem solved...

now to go on a scavenger hunt...

and something just came to me->the chip would have to be from a 1990 or else problems would arise->correct?
Also stock compression would be 7.8:1? Stock fuel pressure 37 psi?

 

[StManTiS]

Alright so now with the stock map it is still doing the same thing, only now it reeks less.

Also i found my spark plugs were too cold and replaced them with NGK Copper 6's. Also spark plug wire to cylinder 2 was in bad shape so i replaced those. It now runs for longer but still dies.

Another interesting thing is that my boost gauge now pegs its needle when the car is starting up all the way down to -20inHG as opposed ot before where it would hover around 15.

The only pattern that there seems to be with the car running is that it goes for as long as the RPMs are increasing, but once they stop it dies.

For example after it start i can push the pedal to the 5k RPM point and it will go it 5K RPM but once it gets there it will die unless i push the gas farther.

I have absolutely no clue what could be causing this behavior. Maybe a fuel pump signal issue?