95 Bonneville 3.8l vin.K wont start

[Tonedog]

Yes, I understood your previous post about the (blue wire), Yes, I do have power going into the tps, & also is grounded. & your also correct that my (blue wire) is not sending anything out to PCM. I used my OHMS meter on the blue wire from the TPS plug to the PMC wire harness (unplugged) & my reading was 0.00, which tells me that there is no resistance, no breaks in the blue wire. So, why wont it send? Am I missing something? I also checked all the throttle linkage for anything out of the ordinary, made sure the TPS blade was correctly placed, & re-checked everything.

[HotZ28]

Originally Posted by Tonedog

Yes, I understood your previous post about the (blue wire), Yes, I do have power going into the tps, & also is grounded. & your also correct that my (blue wire) is not sending anything out to PCM. I used my OHMS meter on the blue wire from the TPS plug to the PMC wire harness (unplugged) & my reading was 0.00, which tells me that there is no resistance, no breaks in the blue wire. So, why wont it send? Am I missing something? I also checked all the throttle linkage for anything out of the ordinary, made sure the TPS blade was correctly placed, & re-checked everything.

If your diagnosis is correct & your meter is reading the way it should, your TPS is DOA! I have never seen a new TPS not deliver some kind of output if it has 5.0v reference voltage! What brand is it?

[Tonedog]

The TPS was replaced 3 times with the same results, the name on the box "Duralst", do you suspect a bad batch from this company, should I get my money back & go to a AC Delco dealer? Can it be that simple?

[HotZ28]

It could be that simple! This is really hard to believe, even with Duralast (Rice) brand! It may be a Chinese conspiracy!

[The_Mechanic_33]

just a thought and I feel dumb for asking,but are you moving the throttle while you are testing for voltage?

[HotZ28]

Another early morning thought have you checked the TPS terminal pins, or have you checked the TPS resistance readings without the terminal connected? It is strange that you would have power going into the TPS, but none coming out, it's got to be something obvious!

[Tonedog]

No, I did not test the resistance on the switch itself, Yes, I did test the voltage while moving the throttle. I returned the (duralst) switch today & ordered one from AC Delco, should be here this afternoon, hopefully it works. The Duralst part said made in Mexico, so the chineese thery may be out... I'll post a reply later today after I get the new TPS.

[Tonedog]

Well, I picked up the new AC Delco TPS, & installed it. Before doing anything, I verified that I have a 5 volt refrence with key on, engine off, (I do), I verified that I have a good solid ground, (I do), I verified that the blue wire OHMS out to 0.00, (It does), the blue wire should also have 0.44 volt minimum & increase to 4-5 volts at WOT, (It still dead) 0.00 volts. I verified that the TPS is actually showing resistance unplugged & increases resistance when I move the tps blade to WOT position, (It does). My question is, If I have a positive 5 volt refrence, & a solid ground going into the tps, why wont it send power out?

[HotZ28]

Originally Posted by Tonedog

If I have a positive 5 volt refrence, & a solid ground going into the tps, why wont it send power out?

That's the million dollar question! I assume your meter is capable of reading less than 1.0v.

[Tonedog]

yes, it reads less than 1 volt, it will read in fractions of a volt

[HotZ28]

You have 5.0v in, and the resistance changes with throttle opening, but no voltage out, you must have a bad terminal on the TPS, or Gremlins in the TPS eating voltage.

[Tonedog]

Ok, we can finally end this thread, the problem I was having was caused due to my personal stupidity which I noticed today after I made up some homemade backprobes & re-tested everything with my DVM again. What I was unable to read was a negitive voltage on this signal wire, the reason it was a negative voltage & not a positive voltage was I kept installing the TPS swithes from left to right which placed the TPS blade incorrectly & therefor giving me a negative reading on the signal wire (Blue Wire). I removed the TPS while leaving it plugged in & attached to my DVM & moved the blade by hand & watched it go to 5 volts, so then I installed the switch from right to left which puts the blade in the correct position & gives me a positive voltage reading to the signal wire (blue wire). I cleared the code & it stayed clear this time. Car is running good again. HottZ28, I would like to thank you for all your time & effort you put in trying to help me solve my problem. I'm normally not this stupid, but this car had my brain fried for awhile & I wasnt thinking straight. Talking with you helped me to get back on track, so even tho you didnt fix anything sort-of-speak, you helped in ways I just cant explain....Thanks again!!!

[Tonedog]

Originally Posted by HotZ28

Are you absolutely sure the tab on the TPS is in the correct position?

I remembered you telling me this, but my brain was fried by this time & I didnt think all the way thru, so...you were absolutly correct, it was not in the correct position after all.

[HotZ28]

Thanks for the candid feedback and don't feel bad, after 50 yrs of automotive experience, I still often fail to look for the obvious. I knew from your first few post, that you had some good knowledge and we could eventually find the solution. It pays to spend some time and try and adsorb what another person is trying to say on these forums. If we could have been in the same shop, this problem would have been resolved in a few minutes. Hopefully, this thread will help others!

[Tonedog]

I AGREE!!! to all that, the working in a shop & diagnosing issuses, we would make a good team, it's pretty much all common sence, but having those sences at the right time when you need them, is what troubles us, thats why these threads are GREAT, were able to bump heads till we find a solution. I can normally figure things out pretty quick, thats why I felt so stupid, I over-thought & forgot the obvious... "I know better than that". Anyways, If anyone else has issuse, I'll be glad to join the thread & help you get your cars back on the road where they should be. Another thing I did to my car this weekend that made a big difference on all the electronics, I upgraded all my power & ground cables ( the cheap factory stuff ) & went to a marine store & bought the 1OT cable after measuruing what I needed & had them crimp all the 5/16th's terminals & heat shrink to all my cables. The bigger wire carrys more current, therefor giving all your electonics the power & ground they've been starving for, it made a big difference. Might wanna think about it for your own cars.