: Tps voltage!

05-19-10, 03:05 PM
While adjusting my TPS adjustment screw and such I realized that some useful information would be what voltage SHOULD my TPS be reading at?

1987 Oldsmobile 307 with Quadrajet Carb.

05-19-10, 03:46 PM
Depending who you ask and where you read...

.4 to .5 (or was it .04 to .05...I'll have to check when I get home)

05-19-10, 04:09 PM
I was under the impression that the TPS on these vehicles were non-serviceable.

05-19-10, 04:20 PM
You can adjust them, they just put a "plug" in the adjusting screw's hole. To remove the plug, you need to drill a hole into the plug and then pull it out (i used a screw to thread into the hole, then pulled with some pliers)

After that, you need a special tool to turn the screw.

05-19-10, 04:55 PM
Yeah, I ripped my plug out with some special mailler's pliers I had.

Okay, so it is supposed to be between .4 and .5 or .04 and .05...Now what OHMs do I set my meter to to measure it?

I probe the terminals for the black and blue wires, right? Do I probe them with the wire harness unplugged, or do I have to probe them while it is plugged into the TPS.

And I probe them with the engine on the ACC position, right? (as in, not with engine running)

I am probably so far off I should have just bought a new Quadrajet, since I found where to get them fairly cheap at about $145 compared to the $200+ that everyone else wants.

When and if I ever get my engine for my swap and I put in, say a 455, I will set it for Dual carbs, so I can double my potential stress.

05-19-10, 05:25 PM
I found the information that my mechanic printed out when I took my car in to get the carb tuned...he must have left it in the car :)

"Remove aluminum plug. Connect voltmeter to black wire (-) and either of the 2 colored wires. If it reads 5 volts, switch to the other colored wire."

yes, the ignition should be in the run position but not started. TPS should be connected. I actually made a testing harness out of 2 old TPS pigtails and an old female end pigtail, but you can backprobe the connectors too.

05-19-10, 07:40 PM
Well, I have no Garage to to go, so it will be me, a sixpack of Guinness and some shoddy tools.

I need to get another AGM battery anyhow, my old one is deceased (though that's not why it's in the back of a Hearse) and deal with that, but I got the whole system hooked back up. 0 Guage wire is awesome. I got the fans and heatsinks for the isolation system on a temporary system, running wile the car is on and they were all free, because the Scottish chick at the PC place kept flirting with me. Sometime soon (possible tomorrow?) I will get the neon lighting back up, because considering I own all of this already and need to purchase nothing to fix it, I may as well get it all running again.

I hate Walmart.:want:

05-20-10, 02:35 AM
I am probably so far off I should have just bought a new Quadrajet, since I found where to get them fairly cheap at about $145 compared to the $200+ that everyone else wants.

Every place I've looked seems to want $400+! Mind sharing the name of this place? Unless it's someone on eBay that only has 1..

05-20-10, 02:36 AM

Though if you're the Ebay type, this guy seems to do a good job.

http://cgi.ebay.com/ebaymotors/ROCHESTER-QUADRAJET-CARBURETOR-Buick-Cadillac-Olds-307_W0QQitemZ140395338173QQcmdZViewItemQQptZMotors _Car_Truck_Parts_Accessories?hash=item20b036d9bd

05-20-10, 02:38 AM
LAME. The JC Whitney link doesn't go through. Oh well, you can just select your make, model and year and find the Carb.

$144.99 is a great deal, methinks.

05-20-10, 02:41 AM
...Though upon review, it seems the price suddenly increases as you try selecting which one you need. What kind of **** ****** ****-**** Marketing is this ****?

05-20-10, 07:31 AM
haha yeah these carbs are not cheap. I bought a used one that was "recently rebuilt" for $150 and it works fine.

05-20-10, 07:24 PM
I'm seriously considering buying one off that guy on eBay in the near future, seems like a good source.

05-21-10, 02:33 AM
I'm seriously considering buying one off that guy on eBay in the near future, seems like a good source.

I see myself doing the same. I looked all through the website and found him. It seems like a great price, the fellow knows what he is doing, you get a warranty, a phone number to call him at and the fact that it's a small shop rather than a franchise asking for cores, means he obviously rebuilds them for a proper profit, or he would have no real use for cores.

05-22-10, 12:42 AM
I asked and he will rebuild a 307's Carb for $185 (plus return shipping) so it is basically just worth it to purchase the new one from him.

water walkin warrior
05-24-10, 04:24 PM
Here is a video that shows how to test and change the TPS. I'm thinking I need to replace the TPS on my 89 Brougham, but I've heard you can really mess up the carb if you don't know what you are doing. I'm getting better, but holding off on doing it myself without supervision of a "carb" experienced mechanic. My other option is to pay someone $50 an hour for labor to change it for me. In you guy's experience, does the TPS generally need to be replaced or just adjusted? I found a new one for $25 and am thinking about just putting a new one in to be sure. The video is here at youtube.com/watch?v=IsX5q3jBeBQ I'm a newbie, so I can't put actual links on here yet. Copy and paste it. I think they show the voltage info.

05-24-10, 05:10 PM
I am aware how to change the TPS and will probably get around to it when and if I ever get the chance. I tweaked it and adjusted it, but no matter what I did, I could not get the voltage to come nearly to where I am told it is supposed to be, or even to register on nearly any setting on my multimeter. Interestingly, I rescanned the codes and the oxygen sensor is no longer an issue, but the code 21 is still prevalent. Formerly, the Check Engine light would go on and the only way to make it go out was to shut the ignition off, but now (As I learned on a long trip yesterday) it will blip on when the car comes to a stop, but disappear again when the vehicle is in motion, so I suppose that's an improvement at the least.