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Tech / General EngineIs your car making a strange sound or won't start? Thinking of adding power with a new combination? Need other technical information or engine specific advice? Don't see another board for your problem? Post it here!
So I can build replace anything but troubleshooting not so much.
First I was wondering cam your tps or maf be bad without throwing codes?
Symptoms are when driving and in fifth gear and doing speed limit at 45 to 75 doesnt really matter the speed. It happens when trying to hold speed limit it starts to stutter real bad. You have give it gas let it coast give it gas let it coast and so on and so on. Could that be my tps?
Next is it backfires everytime i shift gears what could that be? I failed emissions bad i was 5 times over the limit. My NOx passed though. I will be replacing the cat and getting a catback kit.
I check for codes but it gives me none only the 12.
So what do you guys think?
https://www.thirdgen.org/tpimod2 to rule those out. IAC won't be the problem as long as your idle is ok.
Also check fuel pressure.
What did the emissions fail on? That is also a good indication for where solution lays.
HC gpm 11.235 limit 2.5 fail
CO gpm 44.3201 limit 20.0 fail
NOx gpm 2.7508 limit 4.0 pass
Those are my horrible emission numbers. Thank you for the link i will do this part friday. My idle is not smooth at all it lopes from 1500 to 2500 never stalls though.
2nd page post 62 has good vitals on those reports. But the whole thing is a read but do throw out some insights.
Timing, egr, o2 sensor and vacuum are big emission changers. New oil usually helps a little bit. So does a good highway blast on the way to test. But ya, in that link is ias issue too.
Last edited by fokeyman; 09-30-2015 at 10:56 PM.
Reason: double sentence woops
Have you messed with the ignition system at all? If its been performance tuned you may have too much timing. I have the same problem with mine. Simply unplug the timing advance a few blocks from the testing center and re run emissions test drive a few blocks away again and plug it back in. Turn your car off each time you unplug/plug it back in.
Not saying you dont have another issue but if the ignition system isnt stock or you have messed with your timing try it.
As far as testing sensors and that. Its actually alot easier than you may think, Google and a multi-meter and you can test just about any sensor on your car. Just search like testing TPS.
Have not messed with the timing i bought the car for 900 off some idiot wgo use the stick shift cover as a ashtray. He took off smog pump i think thats why the cat is bad he left everything else on. I will have to check timing havent done anything but hook up air system and took to emissions. Thought it would give me a idea of where the car is at.
I am getting a multi meter friday and will go through entire car friday. This is my dream car since i was 10 never owned one started a family at young age now finally got everything on right track bought wifey a 2011 sienna now its my time lol.
You sound kinda like me. I have loved the third gens for the longest time and finally got mine a few years ago and have been slowly fixing everything on it. Guy before me knew enough to be dangerous but was not afraid to cut corners and rig stuff. I dont like that so i have been trying to correct his "fixes" to my standards.
Ok can anyone tell me what voltage reading i should get for maf sensor set the iac and tps idling better but still rough. Bought maf sensor cleaner cleaned it want to check voltage reading.
Ok new problem engine sounds so much better but, i have found several different things. My air block valves are no good so my pump isnt doing anything but looking good. Then i moved on to spark plugs where i found autolite 25 in there the gap has been closed could my pistons be hitting them.
That's not good. By closed you mean, all the way, or just slightly? The last guy might have gapped them wrong if it's only slight. I'm seeing you should have a 24 in there. But 25 is showing identical outside measurements. 24's are used in 87 vin f (and many others, using your profile for this search). 25's were for 85 vin g and s. They are as far as I see are interchangeable. I'm not sure how to measure piston to plug, but could regap them and turn over the engine. Not sure if that is safe for the engine, but at least you'd know for sure.
[QUOTE=fokeyman;5967586]That's not good. By closed you mean, all the way, or just slightly? The last guy might have gapped them wrong if it's only slight. I'm seeing you should have a 24 in there. But 25 is showing identical outside measurements. 24's are used in 87 vin f (and many others, using your profile for this search). 25's were for 85 vin g and s. They are as far as I see are interchangeable. I'm not sure how to measure piston to plug, but could regap them and turn over the engine. Not sure if that is safe for the engine, but at least you'd know for sure.[/QUOTE
I just bought some acdelco another thread said to use those think half my pistons were dead he probably had them gapped wrong they were at .015 i gapped the new ones at .035.
09-30-2015, 07:25 PM
