langzaiguy

For awhile now, right after I adjusted the timing on my 1991 22re PU, the engine has really had a hard time accelerating and has been stumbling. I adjusted the timing by the book--meaning I plugged up the two vacuum lines to the distributor. I used pencils to do so, and I'm afraid one of the tips broke off and was sucked up into what I guess is the EFI (maybe you know better?).

Would this affect the TPS? I checked the vacuum on the E,R, and the P lines. E & P had suction at a raised RPM and R did not. Is that normal? I checked the TPS with an ohm meter. VTA to E2 showed "OL" at all times (throttle fully opened and closed). (I checked this with the engine not running). I'd hate to turn this one into the dealerships, so I'm humbly asking for any suggestions. Thanks!

MMA_Alex

if you got OL (out of limits on the meter) at all settings you must not have had a good connection to the tps terminals. try taking the readings again.

and yes the tps adjustment will effect being able to properly set the base timing.

84sr5yoty

Vacuum advance lines on a 91 22re

Are you sure you have EFI? Only 83 and 84 22re's have a vacuum advance can. 85+ don't as the computer has full control of timing.

n4ynu1010

Try this link for a informative way to check your TPS :
http://www.4crawler.com/4x4/CheapTricks/TPS/index.shtml

TPS will cause the problems you are having as my 3.0 had the same symptoms , check it with this link and replace if needed then re-set/check your timing and base idle settings .

n4ynu1010

Forgot about the pencil tips :
I would follow that line/those lines back and find and remove the pencil tips unless we are talking like a tiny weenie piece of the lead off the end , in that case it would be a crap shoot but still potentailly be a problem , if it goes to hardline then find the other end and blow them out , get them out though as if not already the will become lodged somewhere and cause you some headaches sooner or later .

langzaiguy

Thanks for the advice guys. Yeah, I'm positive it's got EFI. I plugged the two lines that seeming went to the distributor. Both lines connect to the EFI. I really don't want to open that it, I'm afraid I'd be over my head. I'm going to try and take off & clean the TPS. I tested and retested the TPS with an ohm meter and even bought alligator clips to make sure I had a good connection. I still can't get a reading on it. The truck remains off for this test, right?

thook

What kind of meter are you using....what is the range? And, what ohm setting do you have it on?

n4ynu1010

Yeah , trk off and do the tests , this link here is out of the FSM :
http://personal.utulsa.edu/~nathan-buchanan/93fsm/engine/93throttle.pdf

The test for the wide range resistance is important that you do not have any dead spots for this will control your VAFM to control the air in respect to the throttle opening and the other listed as 2.3K or less is generally a few ohms and that lets the ECU know that you are supposed to be in the idle circuit and should open to infinity as soon as throttle is opened at all (hair trigger on that is best) .
The first link I gave you for the adj.'s spell that out rather clear and a bit more simply than the FSM link I just gave you .

n4ynu1010

I use a Fluke Digital 87 True RMS but only because I do much more with it that that of course , a standard meter would work fine , the values for the important settings are not the critical part so much as you pay attention when you test the full range throttle response and the resistance during the throttle being opened is without any dead spots , and the idle circuit setting (one you use a feeler gauge on) should be a closed circuit with throttle plate at idle/closed and this setting should open immediately (infinite) when the throttle is just cracked open .
I did not use a feeler gauge on mine because I was not going to bend one up to measure it , I just adj'ed my new TPS to open when I just barely opened the throttle plate then when I went back and checked the other fixed setting it was 796 ohms , just inside the 200-800 ohm limit .
Set your meter to the scale your working with in the adj. directions , the only one that was different for me was the one that said 2.3K or less as that was actually around 3 ohms which is the Idle circuit switch function of the TPS .

thook

True, but the only reason I was asking him is because when I first started learning to use an ohm meter on testing the TPS I was using a little analog meter that has a maximum range of 1k. I could make no sense of what I was reading because I couldn't convert the values. There were other little anomalies trying to use it, but once I read 4Crawler's tips I quickly scrapped that approach and bought a real DMM that could do the job. It all made complete sense once I could translate what was occurring visually on the meter screen.

In short, since we have no idea what kind of meter he's trying to use, I thought I'd ask and deduce if that was part of his difficulty.

And Langzai....yes, the vehicle remains off. UNLESS!......(tah dum!)

....you care to try adjusting the TPS by hand. You do this with the engine running, though. Doing it this way effectively bypasses any confusion with using a meter. It will also imediately tell you if the TPS is bad.

With the engine running, TPS harness connected, and the TPS just loose enough to manipulate, find the resistive edge where the idle drops and/or jumps. Turn the TPS clockwise just until the idle jumps, then turn it down (counter clockwise) where the idle drops. That will be where it's supposed to sit....tighten it down. Of course, you won't be able to determine the other value settings specifically, but if it's set correctly the motor will go into base timing when the two diagnostic terminals are jumped. You know it's in base timing mode if the idle drops audibly. If NONE of this will happen, then the TPS is bad.

thook

Uno momento.....

Have you (Langzaiguy) pulled the TPS off at any point? You mentioned cleaning it....did you? And how did you clean it if you did?

Also, what are you calling the "EFI"?

n4ynu1010

[quote=thook;50634586]True, but the only reason I was asking him is because when I first started learning to use an ohm meter on testing the TPS I was using a little analog meter that has a maximum range of 1k. I could make no sense of what I was reading because I couldn't convert the values. There were other little anomalies trying to use it, but once I read 4Crawler's tips I quickly scrapped that approach and bought a real DMM that could do the job. It all made complete sense once I could translate what was occurring visually on the meter screen.

In short, since we have no idea what kind of meter he's trying to use, I thought I'd ask and deduce if that was part of his difficulty.

Valid point !!!!!!! The meter does need to handle the ranges of resistances you are going to have to test the TPS which from what I have seen thus far would be a comfortable 20K range , if you are using one of those very limited little meters /continuity tester then you would not be able to test all the functions to see if yours was even bad .
Good thing is that usually some of the cheapest ohm meters generally will go 100-500K .

langzaiguy

I have not taken the TPS off yet. I read that I could clean it while still mounted to the engine. Is regular carb cleaner fine?

I'm calling the grey metallic rectangle that says EFI the EFI. Are those not the injectors? The throttle body connects to it.

I'm using a ohm/volt meter by Commercial Electric. I can't find the ohm range for the life of me.

n4ynu1010

Well make sure your meter can do it (look it up online and veiw the specs) and test the TPS by the book/walkthroughs and then take off if bad and replace after you know its bad , no need to clean the TPS though some say it has helped though DO NOT use carb cleaner , use contact cleaner that is safe for plastic .
With mine it had dead spots in the range test (VAFM) and was infinite when throttle plate closed (not showing ECU it was in idle circuit) , all that said ..............contact cleaner wouldn't help that anyway - carbon traces in the switch were bad / worn out , its pretty much a sealed housing where they are anyway , moral is when it really go's bad most of the time it has to be replaced

If you have to ................. ask a bud to borrow a meter

thook

The grey metallic rectangle is the plenum or air intake body. Whatever one calls it, it's not the "EFI". EFI only means electronic fuel injection. Vacuum lines are attached to it because it is the air intake...creating vacuum as air passes through into the combustion chamber. Your injectors are underneath of it attached to the fuel rail...the longish, tubular metal thing going along parallel to the intake body and head/valve cover assembly.

You should familiarize yourself with the FSM and the blow out diagrams of the different assemblies of the motor.
http://personal.utulsa.edu/~nathan-b...fsm/index.html
Just browse around and look at the different pictures and how things go together so you know what you're looking at. Helps tremendously when you're trying to communicate through this internet thing.

And the TPS...never use a solvent to clean the terminals. It will go bad for sure. It will corrode the circuitry in the sensor housing. Some light denatured alcohol would work with a cotton swab....but, not much. Unless there's corrosion or heavy carbon build up, I doubt you need to clean it, though. And good that you haven't pulled it off, yet. Not that you can really srew anything up, it's just there is a way it has to go back on to work correctly. It's spring loaded against two metal tangs that hold tension on the spring mechanism. You'll feel it when you start moving the TPS around CW or CCW. It's springs back into position in one way. The movement of the throttle plate engages that mechanism and the sensor reads that movement in turn telling the computer (ECU) what the resistance is or where the throttle plate is/how far the throttle is open. God...I hope you followed that!

Your meter....is there just one setting? Does it just say "ohms" and you turn a dial to that and that's it? See if you can find the same model as yours on the net and post up a link or pic....show us what it looks like, would you?

langzaiguy

Oh wow, thanks guys! Some great information! Here is a picture of my ohm meter.

In the opposing picture:
1,2,3 are the vacuum lines I tested. None of them had vacuum at idle, 1 did not have vacuum at higher RPMs.

4 and 5 are the vacuum lines going what I thought was from the distributor. These are the lines I plugged up when checking/adjusting the timing. Both lines are clear. Line 4 goes to the plenum (thanks THook). What does line 5 go to? What are the worst case scenarios if a portion of lead got sucked up in them?

n4ynu1010

#5 looks like the A/C Idle adj. (could be wrong but I believe that is it from the pic)
The lines leaving throttle body should have vacumn at diff. points of engine rpm , this is where the Service Manual comes into play as it will identify them and at the appropriate control that it leads to the FSM will give you rpm and vacumn values to check for .
If you have no vacumn on the lines at the throttle body at any given rpm then I would have to assume that the ports are stopped up indicating that Throttle Body should be removed and thoroughly cleaned , but once again the FSM would clear all this up for you , the lines leaving the Throttle Body are designed to work differently , some may have none at idle and then at higher rpm's with a curve and some will have at idle (the majority) with that vacumn dropping either sharply or slowly during acceleration/load on engine.
Start with the Emissions and PCV and go through the tests and rule out a leak/stopped up line or bad control(ie-egr,pcv etc.) , if all that checks out then you can rule it out and move on , of course check your TPS and MAF or VAFM also , the proceedures and specs are all in the manual , here is the link again for the 93 FSM Online Manual in case I forgot to give it to you earlier :

http://personal.utulsa.edu/~nathan-buchanan/93fsm/

I am pretty sure this is the same link Thook gave you , he is trying to get you to become familiar with your motor as all will have to become if you want to trouble shoot it yourself , if you need help finding specific links then feel free to ask , I am not sure you are very familiar with the meter (at least it seems that way) so maybe it would be best to find the manual to that and go through that , the meter looked to be more than enough to do what you need , although in using it there may be some functions it has that would help you like Auto-ranging setting , that way whatever you are measuring the range will be automatically selected and you will not have to adj the range for the measurement , otherwise you will need to adj the range for the measurement or put it on 20-50K range and then just be careful to read it correctly for the spec'ed resistance .
Hope this helps , if you are not familiar with using a Multi-meter/Ohm meter then become familiar with that first and then move on to your tests , and make that FSM your best friend because the more you know about the controls and switching then the better you will understand what makes that puppy tick

thook

From what I can tell of the photo, the meter has only one setting and only testing for continuity per se. I think what's happening is the range of resistance is "out of limit" for the meter to read. It should be able to read between 500 and 10k ohms. After all has been said, though, something has occurred to me. If you were even able to get the ECU into base timing mode and set the timing, then the TPS is good and all of this is moot.

Worst case scenario...if lead got sucked up...is that you have a blocked vacuum line. If the lead had been sucked into the plenum, it's likely still floating around there or sucked into the combustion chamber and has been consumed. And that I would not worry about. Months ago I was servicing something on the motor and had the air intake tube and AFM off of my '92. I put everything back together only to find once the motor ran it ran much better than before.....then abruptly DIED!!!!!! I pulled the intake off to find dry cat food had been sucked up! Apparently, cat food had gotten into the intake tube before I put it back on. How? I do not know. Very mysterious!! Well, nothing was harmed, though. Just had to pull the plenum and blow it out and the TB. Funny thing is my exhaust in that moment smelled like a Purina factory....(okay, not so funny).

MMA_Alex

cat food in the intake = mice lol

once upon a time I had dog biscuits in the air filter, with little mice bites in em.

n4ynu1010

I tried looking up some specs on that meter but couldn't find so I have no idea what the ranges are or if like Thook said it only has one range , I have a Fluke Ampmeter like that but it has diff. ranges of resistance it will cheack as well as continuity , use the flash on your camera and set the resolution to 640X480 , then we will be able to see what that booger does .