just got done with the build. swapped it in and idles a bit rough. timing is spot on. adjusted the distributor it made it better. gapped the spark plugs (NGK) to 1.1mm. new distributor cap and rotor, new plug wires. new everything pretty much.

My solution:
adjust valve lash
adjust distributor for smoother idle.

what else could cause this? it smells like its running rich. no power when the gas pedal is pushed down. slowly revs up. seems like the engine is being choked.

also the car has sat for over a year. the tank is almost empty. could bad gas cause it to run rough? i am getting 93 octane to put in the tank tomorrow to get new fuel in there.

 

I have the CEL codes P0304 and P1399. could a bad igniter cause this? or coil?

 

Water in gas will do what you described. It essentially retards the timing. By any chance, did turning the distributor towards the firewall make it run a bit smoother? Also what ecu is in use?

 

Also what injectors? Those are both misfire related codes. Your not using iridiums are you? They're famous for misfiring right out of the box. Also try a tighter gap on the plugs. Try something extreme like. 5 or. 6 mm.

 

turning it towards firewall it ran better.its the stock GSR ecu. BUT i checked the timing. the exhaust cam was off a tooth. i corrected that and saw that the intake cam was also off a tooth. fixed that. the car idles a lot better and has a better throttle response.

stock injectors. NGK v-power. and i found the problem with the misfiring. its the ignition control module (ICM) bought a new one from advance auto. i got no spark. going to return that tomorrow. i installed the old one back on. it fired right up but it was getting worse so i quickly pulled it in the garage and shut the car off. tomorrow my friend is bring his GSR distributor over and swapping the coil in there since that's all that is missing. and see if that ICM in his distributor is good or not.




thanks for replying

 

well I swapped in a D16Y7 ICM and its run better. but the misfire is still there. on cylinder #1 and #4. the ICM are the exact same. part numbers are the exact same. what else could cause the misfire?

anyone?

 

Bad wires? Test the resistance across them. Try new plugs and gapping them tighter. Try swapping the plugs from the misfiring cylinders to the non misfiring cylinders and see if the problem follows the plugs. THEN, if it doesn't follow you know its not the plugs. Then, do the same for the injectors. Rotor screw is in place? Tested compression yet? Valve lash too tight? Tested voltage/resistance/signal to each injector? Are you using saturated or peak n hold injectors? If its cylinder specific, think of all the things that are specific to each cylinder:plugs, wires, injectors, valves, rings, valve seals, etc. Start with a compression test then start with the simplest thing I.E. swapping around plugs/wires. Report back after the compression test.

Get that brain working and think, think, think!

 

I got P0301 and P0303 and P1399 when I had bent valves. I was told from a buddy/mechanic it may have been pre-ignition causing the misfires.

 

ill write it all down and get them checked! ill post back here with results!

 

Alright. I received the new distributor and installed it today. It ran better. But it gave me a new code #73. It had #71 and #74 before.

When I hold the throttle at like 3k rpms I can hear the miss but not as bad as before. But then the CEL will flicker and click a lot and the rpms would work its way down to zero. Now my Guess is that there is a short some where because its making the car die.

Anyone have any ideas?

 

is this car tuned by chance.. what plugs are u running.

 

its the stock ECU. NGK V-power plugs

 

theres ur anwers.

 

to what?

compression numbers are

T-BELT ==========> TRANSMISSION
#1 #2 #3 #4
140 135 145 150

Spark Plug gap
#1 #2 #3 #4
1.1mm 1.1mm 1.1mm 1.1mm
(.044) (.044) (.044) (.044)

I tested the injectors with a test light with the clamp on the positive terminal. Then probed the injector clip and every single one lit up. So that means the connection is there.

Also used the test light on the distributor plug for the coil part. The light lit up as well.

I have the code P0304 cylinder misfire #4 still. And code P1399 random/multiple cylinder misfire detected.

I also check spark with the wires. There is spark in all 4 wires. But it was a yellow-ish color spark.

 

anyone?

 

Might be a lean misfire since your running a stock ecu.

 

but wouldn't it say lean in bank #???

 

Not necessarily if it's only a random/intermitent misfire. If it were a continuous misfire, I would bet it would throw a lean code.

 

can I just wire in a VAFC and correct the fuel with a wide band?

 

year old gas... even 6 month old gas is horrible to run. sitting in that tank all year getting hot then when it gets cold.. condensation. drain your tank put a new fuel filter on and maybe even new fuel lines.

 

I already installed a new fuel filter before I swapped the engine in.

 

Piggy back units are trash.

 

Just to make sure, check that your engine coolant temp sensor (on side of the head) is plugged in. I've seen this cause a misfire condition from being either extremely rich or lean because the ECU thinks the engine is at a different temp and compensating for it.

 

just for now. and i agree.

no leaks. and its plugged in

 

Did you put fresh gas in it?
Is it still misfiring on cylinder 1 AND 4?
Or is it just cylinder 4 now?