Thought it may be that , but i ran awire at the sensor to the body[for ground], then tried the frame-no dice--I had just taken off a rusted leaking header put one of those extra thick gaskets-1/4 inch and new header bolts-did i mess up a ground? or maybe just a coincedental hei failure? ---[They cost some good change] already tried a new o2 sensor ----had same outcome------350 TBI 1990 any info? thanks
CK5
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After new header install---truck runs like crap-02 sensor not grounded properly?
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Did you happen to touch the o2 sensor tip with your greasy dirty fingers, while installing it, and kill it?
Runs like crap. Pretty generic.
With cold engine? With warm engine? Heated or single wire unheated (stock) O2 sensor?
With cold engine? With warm engine? Heated or single wire unheated (stock) O2 sensor?
new sensor ran like old sensor------unheated and stock 02 sensor-----cold start ok,it ldled down to an ok idle[ive had better] and as soon as you start to drive,it goes down the road stumbly-then when put back into park- lousy idle.... was good before the new header[maybe the header bolts were treated and dont keep a ground, and my wire isnt good enought for ground?]
Ground isn't your issue. Everything is metal to metal. Coatings aren't going to reduce conductivity in any manner enough to influence the O2 sensor. It's not like we are talking something like ceramic.
If you drive it when it's cold it still runs bad? Where I'm going is that the O2 sensor has no bearing on how it runs when cold. If it runs poorly when you put it into gear and drive immediately after starting the motor cold (as in first thing in morning, or after sitting for many hours) then it's not the O2 sensor at all.
If you drive it when it's cold it still runs bad? Where I'm going is that the O2 sensor has no bearing on how it runs when cold. If it runs poorly when you put it into gear and drive immediately after starting the motor cold (as in first thing in morning, or after sitting for many hours) then it's not the O2 sensor at all.
your gonna want a heated O2 if you've moved the O2 down to the collector on a set of long tubes...
ok- drove it cold---for 2 minutes drove better--- then she started with the hesitation again......got to be a ground or a bad wire in the harness?-but i did wrap a wire around the threads of the sensor and bolted to chassis at first thought-then to frame got same results---- i do have a very fat crush gasket on the header? any input appreciated.....
does that have its own ground? Thanks
yes, a heated O2 has it's own ground.. but that isn't your issue more than likely.... the reason your having probs is the O2 is never reaching the temps it needs to in the collector on a long tube for the O2 to work right.. it's way further down the system than stock manifolds.. thus why you need a "heated" one...
Three wire (heated) O2's ground through one wire IIRC, but that may be just for the heater.
Sounds to me like your O2 sensor is working, need to find out the root cause. Rarely does anyone listen, but you really need to have a scantool (or winALDL or Tunerpro with an ALDL cable and laptop) so you can see vehicle speed, CTS, TPS, MAP, etc are all reading properly. It's also very easy to see if the O2 is working right.
Since it runs ok in what I have to presume is open loop it's unlikely in the ignition circuit. If you take the air cleaner off and look at the fuel being injected, does the fuel spray look consistent, with no large droplets, obvious leaks or difference from one to the other?
Sounds to me like your O2 sensor is working, need to find out the root cause. Rarely does anyone listen, but you really need to have a scantool (or winALDL or Tunerpro with an ALDL cable and laptop) so you can see vehicle speed, CTS, TPS, MAP, etc are all reading properly. It's also very easy to see if the O2 is working right.
Since it runs ok in what I have to presume is open loop it's unlikely in the ignition circuit. If you take the air cleaner off and look at the fuel being injected, does the fuel spray look consistent, with no large droplets, obvious leaks or difference from one to the other?
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I'll check on the fuel spray and let you know--the scan tool stuff is out of my scope and cant afford a mechanic that has one, sounds like a cool tool though..Thanks, BTW would the HEI control the fuel spray droplet sizes?
have you checked for codes?
no codes--
dyeager535: "Rarely does anyone listen"
That never happens.
That never happens.
Tunerpro RT is free, ALDL cable is ~$50, but have to have a laptop. Although I think there may be some apps for smart phones too. How much did the O2 sensor that didn't fix the problem cost?
HEI has nothing to do with fuel, except lack of signal from the ignition module to the ECM will create a no fuel condition as the injectors won't pulse.
This.. Find out exactly what the ecm sees. You can see when it goes closed loop and what the o2 is reading. Depending on what ecm you have you can make a cable for less than 10 bucks. A 2n222 transitor and a few resistors.
02
was 17.99 so i took the shot..
was there a build thread on that part ? i thought i may have read something like that a while ago....Thanks
I'll see if I can find it. it super easy to do.
