mhub91 Posted June 8, 2015 Report Share Posted June 8, 2015 Just picked up a 1986 Stanza Wagon, CA20E, 5speed. Plumes of black smoke at any speed other than idle. I pulled the codes from ECU and it has every code stated in the Factory Service Manual with the exception of O2 sensor. I performed test on all components that threw codes including Temp sensor and MAF. All passed perfectly fine...... Since it's blowing fuel out the back I decided to check and see if the fuel pressure regulator is bad. I pulled the vacuum hose coming from manifold to FPR and found no difference in idle quality. I'd like to add that it starts perfectly when cold! However, when attempting to hot start it is very difficult and I have to hold pedal to floor to start it. This is telling me that (obviously) fuel is leaking past injectors when off...... Two things come to mind. 1. An injector is sticking open. 2. FPR is stuck closed and forcing maximum PSI.... Is it possible for these diaphragm / vacuum actuated FPRs to get stuck closed? I've only seen them get stuck open or have the diaphragm tear and leak fuel.... Quote Link to comment
flatcat19 Posted June 8, 2015 Report Share Posted June 8, 2015 Think anything related to fuel delivery and input info to ECM. Running rich. Yes. You know that already. What is there that may be telling the ECM that its lean? 1 Quote Link to comment
mhub91 Posted June 8, 2015 Author Report Share Posted June 8, 2015 MAF is input, O2 is output ... Weird thing is there is not a code stored for the O2 sensor. But .... to make matters worse ... I have a small amount (very small) amount of bubbles coming up when radiator cap is off. Also seem to be having thicker grey smoke when it warms up - fuel and coolant? Just making small talk at this point... I'm well capable of diagnosing it, it just sucks. That is all. Lol. Quote Link to comment
mhub91 Posted June 8, 2015 Author Report Share Posted June 8, 2015 Small bits of blue smoke as well... Lol. Almost tempted to pull it out and throw rings and bearings in it. Quote Link to comment
datzenmike Posted June 9, 2015 Report Share Posted June 9, 2015 Small bits of blue smoke as well... Lol. Almost tempted to pull it out and throw rings and bearings in it. That's like cutting your head of for a headache. Black means running rich not... needs rings and bearings. The throttle position sensor tell the ECU when idling or full throttle. Anything between it refers to a stored fuel map and sets the mixture based on sensor input. At full throttle the fuel map is ignored and it's run much richer for added performance. There are also water and air temp senders that tell the ECU that the engine is cold and to run richer until warmed up. The equivalent of a choke. 1 Quote Link to comment
mhub91 Posted June 9, 2015 Author Report Share Posted June 9, 2015 That's like cutting your head of for a headache. Black means running rich not... needs rings and bearings. The throttle position sensor tell the ECU when idling or full throttle. Anything between it refers to a stored fuel map and sets the mixture based on sensor input. At full throttle the fuel map is ignored and it's run much richer for added performance. There are also water and air temp senders that tell the ECU that the engine is cold and to run richer until warmed up. The equivalent of a choke. Not to mention it's rolling on 300,000 miles. Like i said, there's most likely a headgasket leak too. Went out and messed with it today a little more. Still, no TPS, no O2, no MAF code.... And smoke appears to be getting worse. Dude I bought it from said he's driven it "maybe" 6 times in the past 3 years. There was a 1mm layer of dust on it! (exaggeration, of course.) Quote Link to comment
flatcat19 Posted June 9, 2015 Report Share Posted June 9, 2015 Fuel injector o-rings all dried out? Rings caked with sludge? Valve stem seals? HG? GL man. These wagons are cool. I hope you get it sorted. 1 Quote Link to comment
mhub91 Posted June 9, 2015 Author Report Share Posted June 9, 2015 I'm addicted to fucking with things that don't need fucked with. For example. One day this WILL have a CA18DET. Quote Link to comment
scooter Posted June 11, 2015 Report Share Posted June 11, 2015 Does it have a shrader valve where your can measure the fuel rail psi? Have you tried adjusting the tps? Different maf or map sensor? Just cus its not throwing a code doesnt mean its not fucked. If it runs good on a cold start - closed loop then gets shitty id defintitly try swapping maf/map sensors and the tps. Even an 02 for shits and giggles. On those ol' tbi chevys when either of those 3 go bad they run like total shit. Blue smoke may be from ring wash. Get it runnin good, then wail on it a bit and see if it stops or gets worse. Quote Link to comment
datsunaholic Posted June 12, 2015 Report Share Posted June 12, 2015 Don't know, but in '86 did they still have a cold start valve? It's like an extra injector, and if it sticks open it's REALLY rich. Or the temperature sensor has failed leaving it in cold (warmup) mode, which is too rich for once its warmed up. That applies to ones both with and without a cold start valve. Quote Link to comment
mhub91 Posted June 12, 2015 Author Report Share Posted June 12, 2015 Checked temp sensor for ecu, it's in spec. It does not have a cold start injector, but it has a air regulator. The main clue is that it only happens if you let it sit for just a second and try to hot start... Quote Link to comment
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