88 V6 running problems

[ray299]

I have an 88 pickup with a v6 motor. The problem is that it starts right up but idles in waves.. high then low. When I step on the gas it wont rev and has small bafires in the intake. I got a code to the TPS but the TPS checked good and even switched it with another working trucks TPS. When the TPS is unplugged the idle goes real high but can be revved with the TPS unplugged...
OK, its not the Knock sensor or its pig tail, the comuter or comuter harness, its not the vaccum lines (all new AND connected) and its not the vaccum valve thing that screws intot the little block thing on the back of the intake and its not the TPS.... Anyone have any other suggestions?
I'm thinking it has to be a sensor because it revvs when the TPS is unplugged...

[2ndGenToyotaFan]

Are you sure the TPS was adjusted correctly, I know it took me half an hour to get it right..... If it idles high, but you can rev it with the TPS unhooked I think that means it's a bad TPS, or tps wiring..... Some good info here:

http://www.4crawler.com/4x4/CheapTricks/TPS/index.shtml

[ray299]

Originally Posted by 2ndGenToyotaFan

Are you sure the TPS was adjusted correctly, I know it took me half an hour to get it right..... If it idles high, but you can rev it with the TPS unhooked I think that means it's a bad TPS, or tps wiring..... Some good info here:

http://www.4crawler.com/4x4/CheapTricks/TPS/index.shtml

Thanks, there was alot of good info in the write up.
I thought I set the TPS correctly... I even tested it to see if it was good according to the book. I guess I'll have to start there again and recheck the setting.... Wouldnt that be a p#sser... change the knock sensor, harness and comuter to find out its a TPS adjustment...
I'll let ya know later in the week...

[ray299]

I figured out the problem... When I changed to TPS I put it bakc in wrong. First I put it in too far back, then too far forward and now I just realized that the prongs have to fit in the little grooves exatly (not before or after)... so I guess you could say it was adjusted wrong.
I changed it because the idle would serge when the brakes were applied. Dont know if I still have that problem since its not back together yet... If I do I'll have to repost under a different topic...
Thanks for the info though. It was much easier to read than teh book...

[2ndGenToyotaFan]

The surging durring breaking is usually caused by your idle adjusted too high. Turn it down at the screw on the intake near the TPS. It's a sort of big standard head screw I think.

And yeah, I know about the grooves in the TPS, you have to get it just right!

[ray299]

Hey, I reposted un "CODE 52"...

[2ndGenToyotaFan]

http://www.off-road.com/toyota/tech/codes/

KNOCK SENSOR SIGNAL--OPEN OR SHORT IN KNOCK SENSOR SIGNAL

--KNOCK SENSOR/CIRCUIT

ECU

Check the wire to your knock sensor, mine was off when I got the truck, and does not hold on real tight. I'm not sure where it os on the 3.0

[ray299]

Originally Posted by 2ndGenToyotaFan

http://www.off-road.com/toyota/tech/codes/

KNOCK SENSOR SIGNAL--OPEN OR SHORT IN KNOCK SENSOR SIGNAL

--KNOCK SENSOR/CIRCUIT

ECU

Check the wire to your knock sensor, mine was off when I got the truck, and does not hold on real tight. I'm not sure where it os on the 3.0

Its under the intake
I'm so not looking forward to taking the top end apart again....

[2ndGenToyotaFan]

I was afraid of that..... I modified my 3.0 so I could remove the bitterfly valve section of the intake and flip the top of the intake over without removing all the vac lines, I had to cut/bend and remove a few bolts on a hardline vac line that goes under the top of the intake I think. It was a while ago.....