munro701

my 88 pickup wont pass emissions. I put in new cap and rotor, plugs and wires, the old throttle positioning sensor was busted so i fixed that, i ran some seafoam through it, rebuilt the whole muffler and it passes in all sections except the hydrocarbon section. The limit is 160 parts per million and im running 180. I dont remember the exact numbers but somewhere in there. The O2 sensor is still good and redoing the catalytic converter wouldnt take me down enough to pass. All in all, im not burning all the fuel, somebody said to throw in some plugs that burn hotter than the NGK plugs i have in now, and somebody else said to check the timing, but i really dont know what to do except give it to a mechanic

Lummpus

you can try hotter plugs they might work. If you retard the timing that would be your best shot. I just did that to a friends blazer he was at 220 on the hydrocarbons we retarded him about 6 degrees. it ran like crap but he passed.

mikelusk1

x2

retard the timing... or get an MSD system... (and get me one too)

sb5walker

How's your compression? If poor, that will lead to poor emissions, and there's not much that can be done.

You didn't say how many miles, nor what shape the injectors are in. If high miles, you may have unbalanced injectors. Getting those cleaned and balanced may be needed. I've heard good things about Witchhunter Performance - $18/injector plus shipping: http://www.witchhunter.com/

If no time for witchhunter (they're quick, tho), next best is having a shop run concentrated injector cleaner directly into the fuel rails. If they do that, have them check fuel pressure while they're at it. Cheaper alternative is Red Line SI-1 Complete Fuel System Cleaner - add to 2/3 tank gas and run down to 1/8 - 1/4 tank. Do that twice for best results, second time fill tank to 3/4.

Check your air injection system (PAIR) - it is supposed to inject air into exhaust to help burn off stray hydrocarbons. Check that the PAIR vsv is delivering vacuum to the PAIR valve. Check operation of PAIR valve - two ways to do: listening for "bubbling" at air cleaner end of PAIR hose or pulling off the PAIR valve and checking directly - both explained in fsm. I don't have access to an 88 fsm, here's the 93:
http://personal.utulsa.edu/~nathan-b...20pulsedse.pdf

If your Nox readings are comfortably below limit, your EGR is fine, but if dangerously close, check that too.

When you say O2 sensor's okay, what's that based on? It could be functioning "normally" but reading too lean (below .45 volt) or, with a 20 year old vehicle, the wiring and especially the connector could have corrosion, and it doesn't take much to turn a .6 or .7 volt signal from the sensor (a rich reading) into a less-than-4.5v signal (a lean reading) by the time it makes it to the ecu.

Since you know the mixture is too rich, try reading your O2 sensor volts directly by back-probing the connector. The two wires that are the same color are your heater circuit: ignore those and read the other two wires. If not above .45 volts, the sensor is not reading accurately and needs to be replaced. Clean the connector as best you can.

You can also try back-probing the O2 sensor leads at the ecu and comparing to the sensor readings.

BTW the seafoam treatment could have gummed up the O2 sensor.

Is the cat original? Maybe time for a Magnaflow direct fit - under $100 on ebay. Probably get a bit more power out of the bargain.

Is your tps adjusted perfectly according to fsm spec?

Check all parameters of the vaf meter and make sure they're in spec. Also check the ECT. The O2 sensor, tps, vafm & ect are all critical sensors and they ALL must be working perfectly and have perfect electrical connections with the ecu in order for the motor to run right.

Check signal rotor clearance and signal coil resistance in your distributor, clean the distrib connector, the connectors at the coil & igniter, clean the igniter ground. The NE signal generated by the signal rotor & coil are what the ecu uses to time the spark and fuel injection pulses - it's important that the ecu is receiving the NE signals okay.

Check the resistance of both circuits of your coil, and also check performance by pulling coil wire off distrib and holding a half inch from engine ground (with a VERY good insulator and while not touching any other part of truck) and have someone crank the motor. Spark should be bright blue. Slowly pull wire away - spark should keep jumping until almost an inch. Don't do this very long because you're sending pure fuel to the cat which could cause it to get so hot it glows red, and that could damage it.

Did you install a new air filter with those ignition parts?

Are all your ignition parts Denso or at least NGK? That's always safest.

Cleaned the throttle body lately? Use throttle body-specific cleaner, not carb cleaner, get the back of throttle plate w/toothbrush, make sure to give several good shots in upper and lower air bypasses, don't get solvent on tps - will kill it.

Run another seafoam treatment, or water injection, being careful not to allow too much fluid to enter too quickly - in other words, avoid hydro-locking your cyls. Do it before installing new cat & O2 sensor.

I wouldn't set timing below 3-4 deg btdc. If compression is good, you should be able to make it pass at 5 deg.

If you live near a station that sells E85 (85% ethanol fuel)...
http://e85vehicles.com/e85-Washington.htm
http://e85prices.com/Washington.html
...you might consider adding a gallon of it to your tank. Don't add much more than that, though: ethanol can degrade pump seals and eat the aluminum in the pump and your fuel rails.

munro701

im at 216xxx miles right now...i was talkin to a guy at school who said if i wanted to pass by cheating i should run it down to 1/8 tank then put in a bunch of the stuff that contains lots of alcohol cuz an engine can run on alcohol and its not a hydrocarbon

i was lookin at all my hoses on the EFI and three or four arent hooked to anything and some of them i busted when i was changing spark plugs (8 stitches later) i dont know if that has any effects

-side note- is there any way to get a "map" of the efi hoses, where they go and what they do anywhere?

thanks a lot for all the help and especially sb5walker

cant wait for summer when i overhaul my whole truck

sb5walker

The good news is that most of the things you do to clean up emissions will result in your motor running more smoothly, with more power and better gas mileage. Even something like the EGR, which reduces combustion temps to reduce the formation of nitrous oxide, also reduces heat stress on the engine and head gasket, reduces pinging, and improves mileage. There are things you can do to "cheat" a bit on the test, like adding a small amount of E85, but you will still need to get the motor running better in order to be confident of passing and not wasting any more time & money. Alcohol is a less emissions fuel, not a zero emissions fuel, and if you add too much alcohol, you will throw the stoichiometric ratio off because the engine wasn't designed to burn a fuel that requires a so much higher ratio of fuel to air. That could potentially result in a worse test result. But if you add a gallon of E85 to say 3/4 tank, that may help you pass.

Look on the underside of your hood for a vacuum hose routing picture, also check out the online manual. Many of those hoses are for purposes other than strictly emissions - they are there for a reason and need to be hooked up properly. That could be part of your motor's problem.

I would say, check your sensors, especially the O2 sensor, and clean up the O2 sensor connector as well as possible. Replace any sensors that are out of spec. Make sure the PAIR vsv & PAIR valve are working and the passages are clear. Get all those vacuum hoses hooked up properly, replacing any that are hard or cracked. And if your cat is original, you CAN improve your emissions by getting a Magnaflow, so that might not be a bad idea if you can afford.

Good luck - let us know how you make out.

munro701

thanks everyone, i wrote everything down and heading out to my grandpas shop, not this weekend but the next weekend cuz this weekend is prom ;]
i was also screwing around with some hoses and found out i busted the idle sensor, i think thats what its called. if i plug off one of the hoses that connects to it, my motor bogs down so that will fix my 1000rpm idle.

i was also talking to the woman i bought my truck from and she said that she had drove it into a mud puddle and submerged the truck for about 20 mins, think that has anything to do with my problems?
(i thought women were careful with their vehicles???)

sb5walker

Stop screwing around! This is serious!

The tps (black plastic thing on side of throttle body with wires attached) senses throttle at idle, as well as position of throttle, but that doesn't have any hoses attached to it. Can you post a pic?

Depends. How deep was this "puddle"?

munro701

lol i wasnt screwing around...story:
i was changing the 4th cylinder spark plug and it was real stiff so i had to put myself in an awkward position, when it finally went my hand slipped off of the ratchet and my forearm hit the idle sensor (i think its called a vsv sensor) which broke me and the sensor ( i could see bone)...

maybe i should have just said "looking at the hoses"

and the puddle was deep enough that water soaked the air filter 0_o

The Busted sensor

Wound from busted sensor

TPS

plugged off hose

sb5walker

Ouch! Looks like a worthy war wound... and looks like it will be a nice scar when it heals over. Don't forget to wear your hockey gear next time.

That isn't a sensor, it's a vacuum solenoid valve, or vsv. What's more, it's your PAIR vsv. Oops! No passing emissions without that one. But it may not be completely broken - the part that broke is just off the bottom of the picture, right? The little black cylinder? That's an air filter that the hose from the PAIR valve connects to when the vsv is OFF. When the vsv is ON, it connects the hose from the PAIR valve to the other hose, which is the vacuum hose (normally) connected to the plenum. That's what opens the PAIR valve. You can check the operation of the vsv by following the procedures in the manual:
http://personal.utulsa.edu/~nathan-b...20pulsedse.pdf

If it works, no need to rush to replace the vsv just because of the missing filter - it's not critical. Pick one up the next time you're at a junkyard, or watch craigs/ebay. In fact, if you can find the piece that broke off, you can try to superglue it back together.

When you reconnect the hoses, make sure the one from the PAIR valve - that's the one with the orange checkvalve - is plugged onto the fitting that is closest to the red body of the vsv.

Ouch again! That was quite a "puddle". Well, apparently she had some work done after that little incident, or I doubt it would be running. The main result that affects the truck now is probably corroding electrical connections. I'm thinking especially of the O2 sensor connector. I would definitely pull that apart, inspect, and clean those pins as well as possible.

I would also ask her if she changed all transmission and differential fluids after the truck went for its little swim. If she's not sure, change them.

The Busted sensor
[pic of PAIR vsv]

Wound from busted sensor
[pic of heinous wound]

TPS
[pic of tps]

plugged off hose
[pic of where the PAIR vsv vacuum hose is going to be when getting the next emissions test ][/QUOTE]

Take care of that wound - engine grime is bad enough on the outside, but when it gets inside a cut, I find it likes to cause infection.