Way too much fuel


New Member
Aug 20, 2015
My 87 GN has been running great for some time but my luck just ran out. Started idleing poorly with IAC at 00 so I checked under hood and found two vacuum hoses off. Reconnected and thought I would be good. Not so fast. She started but I immediatley smelled fuel and the engine stumbled at idle. I drove it home but it just ran crappy with no power and was just super rich with lots of fuel smoke from the exhaust. I did get a 34 code on Scanmaster.

I have reset ECM and reseated plug, changed O2 sensor, checked all connectors at MAF and translator, jiggled wiring harnes while car is running, traced fuel injector harness to see if something was grounded, checked for blockage in air filter/intake system but thus far nothing has helped. Fuel pressure is 38 psi with vacuum line on regulator which is what it has been for a long time. I have put no new parts on the car for over a year probably and it has ran good for several thousand miles so the inroduction of new hardware is not a factor.

The car is really running rich, fuel smoke comes out thick and there is even fuel seeping out around where the turbo (TE44) mates to 90 stock elbow while the car is running. Anyboby ever seen that before!?

Numbers at idle:
AF -11
L8 - 61
Int - 128
BL -128
CLE - 120 i have not been letting it run long because I know the cylinders and oil are getting fuel washed
AE - 84
TPS -.42
IAC 66
02 - 400-410 this number did not change after changing O2 sensor

Where do I go from here? Change MAF and Translator? EMC or chip? I know I need to check voltage at MAF and will do that. What else should I consider?

Thanks, Dan
No, FPR vac line is not wet with fuel. With vac line off fuel pressure is 42.

So weird though, I believe fuel is seeping out around the turbo while the car is running. That doesn't make sense to me unless something is really wrong??

So I changed the ECM to my spare and no real change, still idle super rich with fuel smoke out exhaust. Also put out the 34 code again. I checked voltage at the MAF on the middle pin (is that B?) and it was 10.6V. That sounds higher than it should be. When I disconnect MAF car runs a little better but is still very rich and screwed up.

I looked at my EMC plugs and they are in great shape with no visible corrosion. This car spent 29 years in southern CA and has very little visible corrosion on anything. But, I'm sure there could be some somehwere.

The are car does respond to thottle fairly well but she is just crazy rich at idle with fuel dripping out of the tail pipes at idle and smoke as you throttle up and down.
A buddy had the same issue and it was an injector stuck open. Maybe try disconnecting one injector at a time and see when the fuel stops dumping. Hth
Yea, I'm thinking its an injector stuck open too. Just so much fuel, it almost has to be. I guess the excess fuel could create the 34 code? Not sure about that.

Next step will be to disconnect one injector at a time and see what happens.

If anyone has any other thoughts please send them!

Thanks guys.
Before you damage the engine by running it, let it cool and remove the spark plugs. By looking at them should tell you which cylinder without starting it.
W/ that much fuel being injected, Mikes suggestion should determine the inj condition.
If the inj is suspected to be shorted, Take the VOM, and check across the pins. Should read correct ohm value for that particular inj design. Then, check from a pin to the metal part of the inj. Should read open.
Also, KOEO, check for 12v at the supply side of the inj plug, to engine gnd. Then, check ohm value from other pin in the plug to engine gnd. Should be open. If there's continuity, the harness is shorted, and that inj is on as soon as the key is on. You said the spare ecm did the same thing, so I'd assume the ecm driver{s} are not shorted.
Take one of those little square batteries and hookup 2wires to it and it would be nice if you had 1 injector connecter to plug it in to the injectors but any how one by one unplug the injectors and put the 2 wires from the little battery to it .it should click.

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With code 34 present the ECM will create and use a default airflow value (based on TPS & RPM). So when the SES/CEL is on for code 34 and there are larger then stock injectors installed, it will run rich. Fix the MAF error and the rich issue will go away.