1G Compression test now no start

[enriquez2000]

Did a compression test and numbers were low as expected(car still ran ok).. tried to start the car after checking all 4 cylinders and it acts like its not getting gas stumbling and thumping at 500rpm with foot at wot and dies as soon as i let off.. starter fluid seems tobget it to start a bit better but eventually it gets used and goes back to thumping.

Used link to verify fuel pressure to the rail. Checked injector pack resistance and it was good. Coils are good and did a firewall spark test to verify spark.

Not sure what else to check. The only thing i did was unplug cas to do the test and plugged it right back on after and now this.

 

[spyderdrifter]

What were your compression numbers?

From a post I made earlier today for another member:

Found this on another post:

" From the VFAQ:

1G (90-94) T/E/L 1.8L NT engine
Compression ratio 9.0:1
Standard compression 185 psi
Service limit 131 psi

1G (90-94) T/E/L 2.0L NT engine
Compression ratio 9.0:1
Standard compression 192 psi
Service limit 145 psi

1G (90-94) T/E/L 2.0L Turbo engine
Compression ratio 7.8:1
Standard compression 164 psi
Service limit 121 psi

2G (95-99) T/E 2.0L NT 420A engine
Compression ratio 9.8:1
Standard compression 170-225 psi
Service limit 100 psi

2G (95-99) T/E 2.0L 4G63 Turbo engine
Compression ratio 8.5:1
Standard compression 178 psi
Service limit 133 psi

2G (95-99) T/E 2.4L NT Spyder engine
Compression ratio 9.5:1
Standard compression 192 psi
Service limit 146 psi "

 

[92AWDHX40]

Any codes like the cts coolant temp sensor. Or a bad maf.

 

[pauleyman]

Usually its the last thing you messed with

 

[enriquez2000]

Comoression was bad like 100 across all 4 bad.. but it started and ran ok. All i did was pull connector off cas.. compression test then put connector back on.

Didnt mess with anything else...

 

[spyderdrifter]

Why'd you pull the cas connector for a compression test?

 

[enriquez2000]

Why'd you pull the cas connector for a compression test?

To stop it from starting.. its how i prime the turbo after a fresh install 6months ago

 

[spyderdrifter]

I guess that makes sense, I got a 6 bolt in my spyder, but I've always just unplugged the plug wires and injectors. Makes sense though.

 

[enriquez2000]

I assume if one of the cas wires was broke id not be getting a spark would i? Im really confused with this since I seem to have spark and fuel...

 

[pauleyman]

I assume if one of the cas wires was broke id not be getting a spark would i? Im really confused with this since I seem to have spark and fuel...

Seem to? How did you check. You either are or are not getting those. Which way is it?

 

[enriquez2000]

Seem to? How did you check. You either are or are not getting those. Which way is it?

Spark jumps from plug to firewall when i crank
Fuel gauge reads 43 psi when pump activates and when cranking

 

[pauleyman]

That means you have fuel at the rail. Does notmean injectors are firing.

 

[enriquez2000]

That means you have fuel at the rail. Does notmean injectors are firing.

True... ill check them tonight with an led .. ran out of daylight yesterday before i could.

Not sure how they spontaneously quit though.

 

[enriquez2000]

Oh and i did test resistor box and it ohmd to spec

 

[pauleyman]

True... ill check them tonight with an led .. ran out of daylight yesterday before i could.

Not sure how they spontaneously quit though.

Sure you do. Last item you messed with. Cas. Should be your number one suspect

 

[enriquez2000]

Sure you do. Last item you messed with. Cas. Should be your number one suspect

Is it possible that unplugging and plugging it back in killed it? I mean i get what youre saying because its the only variable in the equation

 

[ThunderChild]

The connector, pins or wires may have been damaged when you unplugged it and reconnected it, that is exactly what id be looking at as the culprit.

IIRC, on 1gs the CBS and MAF work in conjunction to tell the fuel pump to turn on while cranking (may just be the CAS during crank), as well as telling the injectors when to fire. If something was damaged on the CAS, that would cause the issues your seeing.

Could also verify mechanical timing to be safe.

 

[boostdawd]

Check the wiring on the CAS. They get brittle and hard. Any movement may break the wires.

 

[enriquez2000]

Anybody sell replacement connectors? Id swap it out just so i know i have fresh contacts

 

[enriquez2000]

Injectors look like they should be working....

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I have spark which i verified by letting plugs jump to firewall and i have fuel to rail and injectors firing. What should i test next? I am stumped

 

[jakk220]

Well if you have air, spark and fuel, you only have two realistic options left. Either you have too much or too little of one listed, or its not happening in sync. I would check timing.

 

[enriquez2000]

What wires on the cas connector would be suspect for not showing proper timing? Timing marks all seem to line up

 

[jakk220]

Yellow wire is Cam signal. Should have 4 pulses per revolution.
Top dead center signal wire is white. It should have 2 pulses per revolution

 

[gsxeclipse102]

Check the spark plugs. Maybe one got damaged during removal. Also check correct order of spark plug wires. If the fuel pump is coming on and your getting injector pulses i dont think the cas is your problem

 

[enriquez2000]

Ill try replacing them all and see what happens... cant imagine if one went bad id have a no start.. maybe a miss