fuel pump ECU

 

Just swapped the MAF, no change.

I have the main ECU out and the caps are not swollen or leaking, but I do have some very light corrosion on the legs. That's kind of 50/50, not an indicator either way, but not blown out for certain.

 

the resistor R867 looks like it has some sort of corrosion? certainly doesnt look normal to me

 

irrelevant. calcium build up on circuit carrying + voltage is common. Look at your battery post. That's surface level.

 

My ECU caps were all blown on the underside, unlike all the computers I fix on a daily basis. The only sign was the crud falling onto the board below. The tops looked pristine.

Back to my question re. the TPS - you did make sure the throttle closed switch within the TPS is working properly? It's easy to slap on a 4-pin plug from a PC power supply to test on the car. I'm sure this isn't news to you; just covering everything.

 

MJ, I'll get into the TPS stuff later. I appreciate the thought. I am replacing two caps on the ECU right now because they have a slight possible leak to them. I've had caps that look a lot worse still work properly as long as the dialetric is still supporting two charged plates, but since it has some evidence of possible issue I'm swapping them out now.

Ran to Radio Shack and got two caps. They were 100uf 10v and I am putting 100uf 35v back in. They are a little beefier due to the higher voltage and it should help with longevity.

 

Caps needed some work, but unfortunately didn't fix the issue.

I need to search and find the TPS readings so I can go test it again. I forgot what it was now it's been a week.

89452-33010 toyota

 

My TPS seems to be working properly as it changes my idle when I adjust it and changes if it stutters when I adjust it. I had an 02 code and I was thinking maybe I was having an issue with it shorting and causing the car to cut off at idle. Any takers?

 

Is that either one for a 92 400? I am outside under the hood so not searching until I get a chance.

The one on ebay seen below fits "everything" toyota (nearly) supposedly by the listing.

 

upstream are both the same, down stream has two different part numbers. Denso is a 234-4211 for the upstreams.

 

Thank you much, I had to wait till today to get the spare TPS to test and it was fine as suspected. I'll be O2 hunting tomorrow.

Do you suspect my situation would change if I unplugged the O2 if it was bad? The CK eng light comes on dull barely for a few seconds and then the light gets very bright and stays that way. I was thinking perhaps it is shorting out and what would happen if it were not there at all to give a baseline reading?

 

O.L.T. - hey buddy, it's been about 8-9 months since your last post on this - any update on your Idle issue, and (with luck) a solution.

I'm fighting the same battle with my 1993 SC400 and your situation seems to be fitting mine to a T!

 

Need an update on this if you've fixed it OLT. I've been having codes 24, 28, and 31. And today, after driving it for a couple of hours and rested for a while, the idle spikes up and down until it stalls. It drives really good just like yours, no problem whatsoever, and turning off the AC helped for it not to stall. TPS is to specs - adjusted not more than a year ago, 12 volt mod, everything brand new OEM Denso; spark plugs, spark plug wires, distributor rotor and cap, main and sub o2 sensors, I have 3 MAF's all passing voltage and resistance tests that I switch around ever since the codes appeared about a month ago, ECU is also in perfect condition when I opened it up. Ali is helping me, and we were suspecting the engine ground behind the head, but it's really really hard to reach I can't even see it. I'm gonna try looking at it again tonight 'cause this is my daily and need it running. Any info would help, thanks.

 

I hope you would respond to this since the last time you updated was last year. Thanks.

 

Chiming back in myself on this - O.L.T. - what's the word mate?