Discussion in '1984-1988 Build-Up/Project Threads' started by Justin Danger, Aug 14, 2016.
This is what i meant by base timing
cool, yeah, thats what i've got for now. I'm readjusting my TPS, and have hooked up a gauge to measure the air pressure in the intake manifold.
I've got the engine running... kinda. I had to adjust the stop screw on the throttle valve to get it to run, so I am leaning towards the problem being with the idle air circuit. I did notice that adjusting the idle speed adjustment screw did nothing earlier.
I did some tests on vacuum and while doing that I noticed that adding a shot of starter fluid dropped the rpms, so that leads me to believe that the fuel/air ratio is too rich, and it starving for air. Does this make sense?
I've always considered a wideband o2 sensor setup, does anyone have any suggestions of widebands that they have had good luck with?
If the mixture is too rich, it could be a couple of things, from most likely to lest, the coolant temp sensor is not connected damaged or has a wiring fault. The air flow meter is damaged (due to backfire) . There is a rag stuck in the intake somewhere. an injector is leaking, Or finally your truck just hates you
The coolant temp sensor haunted my Supra before I decided on a full engine swap, surprising how much that thing controls the whole machine.
IACV is dialed now, TPS is the best I've done on that little majigger. Next up is the coolant temp sensor. Most of what I have seen for measuring the coolant temp sensor says to take a measurement hot, and just make sure that it changes when it gets cold. Are there value that I am looking for, or just a change in values?
AFM I'll check too.
All rags are present and accounted for
Thinking of finally getting my injectors sonically cleaned and rebuilt.
any progress is progress right?
Oh yeah, and I got the new fuel pressure gauge installed on the back of the fuel filter. Pressure seems nominal.
The resistance is high when cold and low when hot, thats why if there is an open circut, (eg broken wire, corroded termenal ot broken sensor) the ECU will think is -40 an dump a heap of fuel into the engine. I couldn't find a chart for your truck, but have a look below you will get the idea. If its faulty I would expect to see it at a high resistance or completely open circut from your description of the fault.
A good way to check the wiring to the ECU is to disconect the coolant temp sensor while the engine is running, it will bog down and maybe stall. You can also short out the temp sensor wires on the plug with a paper clip so the ECU thinks the engine is hot, and the enigne should run fine as long as its not crazy cold.
DUDE! great tips! yeah, for some reason there isn't a chart for this one, oh well.
I've got a couple days off in the middle of the week, gonna throw some solutions at that engine and see what sticks.
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