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Does anyone know what this is? I have replaced fuel filter, checked electrical connections, checked for vacuum leaks, pulled and cleaned throttle body and idle air comp., found a disconnected (now connected) coolant temp sensor. There seems to be a small range in the throttle that makes the engine buck and sputter. https://www.youtube.com/watch?v=_YLp...ature=youtu.be
1991 22re pickup 4x4
New plugs, new cap and rotor, new fuel filter.
Compression test within tolerance. in the 145 range with max of 12 psi between highest and lowest.
Last edited by JmanTaylor; 08-22-2016 at 06:01 PM.
Reason: Additional info
Check for codes, I would really look into the AFM. Make sure it is moving freely and do a resistance check on it. Those can be bad and not throw a code.
a few weeks ago and I think everything was ok. I cleaned the AfM and made sure it was not sticking. I will do the test again and post the results tomorrow. Now that you mention it, the exhaust stinks a bit when it heats up and when I did the compression test and pulled the crappy Autolites Advance auto took the liberty of ordering for me in place of the NGKs I called about, they were a little white. I marked the foul smell up to a new muffler but it may be bad mixture. Got the Autolites for free for the mistake but I still think they are, at best, a good backup to keep in the glove box. Getting new NGKs Wed. If I can sort out this last little gremlin, I will have one bad ass truck.
My values / Normal Spec
Vb - Vc 101 / ohms ~100 ohms
E2 - Vs 117 / 20-400
E2 - Vc 181 / 100-300
E2 - Vb 281 / 200-400
E2 - Tha 2k (77degrees) / 2k-3k (68degrees)
E1 - Fc open / open
I did open it up and adjust the dial about 7 or 8 clicks counter clockwise to rich it up a bit. Will see how that does when I get it all back together tomorrow.
Last edited by JmanTaylor; 08-23-2016 at 01:53 PM.
You point out that there is a narrow range where it sputters more. Have you driven it like this?
You're revving in neutral with no load, does that sputter occur more under load? Or make no difference?
What else have you done to the rig lately? And when was the last time at ran right?
You said you added 7 or 8 clicks to richen it. Where? Adjusting the sprocket of the AFM is a lot. Even with the hot cam and oversized valves I ran in my 22RE I only adjusted the sprocket 3 teeth and ended up backing it down to 2 teeth until I swapped in a Supra AFM.
I did open it up and adjust the dial about 7 or 8 clicks counter clockwise to rich it up a bit. Will see how that does when I get it all back together tomorrow.
that is way too severe of a change, even with a perfect engine, and i don't see how it is relevant to the problem that you are having.
if something is screwed up at some portion of the rpm range, i'd be wondering about the tps.
Good questions...
Driven - Yes - See below
Load - Good
History _ i dunno ( I just bought it but the past owner kept pretty good records)
So When driving it drives just fine until you are at a dead level or downhill where you are just barely on the throttle. That's when it does it. Under load, like going up a hill, steady or fast acceleration it does not do it. I had 1500 lbs in the bed a few weeks ago and it never did it. I guess cause you are never at that "even keel".
I have only had the truck for a month. I got it right because it dint run well. I now have it running like a top with twice the power as when I test drove her. All except for this one little snag.
So first thing I did was complete tune up, oil, filter, plug wires, plugs (Flippin Autolites), dist cap, rotor button, throttle body cleaning and the little cold start thingy at the bottom of the throttle body, seafoaming, new throttle body gasket, fixed all vacuum leaks, jetted all vacuum ports on the throttle body, new fuel filter (set the engine on fire due to a spark during this process. No major damage but I replaced the entire wire harness due to some charring. The problem existed prior to the fire.) Compression numbers are C1-148, C2-147, C3-155, C4-143. A little discrepancy between 3 & 4 but should not cause that shudder. The guy that sold her to me kept all the records, new fuel injectors in 2012 (not sure how good they are though).
OSV - It does not seem specific to the RPM, I have had it under load through the range and it does not do it. Only at that point in the throttle or when you are just barely accelerating to maintain speed when driving. I can haul a ton of bricks with no trouble but maintaining 25 mph through town it shudders.
I may back off that 7 or 8 clicks. I have not sealed the cover back yet.
It is like I am sending the signal for just a little bit but the engine panics and does not know weather to send fuel or cut it so it does both at the same time.
Last edited by JmanTaylor; 08-23-2016 at 06:06 PM.
OSV - Yeah, but it was more pronounced in conjunction with all the other issues, I guess. With this engine it's a bit like panning for gold. You start out with a pan full of mud and stuff and as you sift things get clearer.
There was a huge vacuum leak somewhere in the bottom side of that throttle body assembly. After pulling it, cleaning everything, new gaskets, etc... the leak was gone but I was left with this last nagging issue. It is hard to say if I had this exact issue prior because it ran so rough with the leak. I am open to suggestions on where you are going with this.....Could I have jacked something up?
if the tps was on there when you cleaned the tb... people have posted that the chemicals or whatever that are used to clean up the tb can damage the tps... plus, it did throw a tps code at at some point.
Ok, messed around with the throttle body vacuum hoses again, unplugging each one and checking for suction at different rpms. Completely by accident, stumbled into my problem. The EGR port sucks air when I throttle up. With the EGR vacuum hose off the throttle body, it accelerates like a dream. No shudder, no hesitation, no nothin. Plug it back in, same problem. For ˟˟˟˟s and giggles with it off I tried to suck air through the hose as I throttled up (ya gotta die from something). The engine immediately dies. So I am assuming that when the TB needs air from that port at the specific rpm range, the EGR is not giving it and causes the engine to stumble but not shut down (much lighter vacuum than my sucking). So I put a screw in the existing hose leading to the EGR, put another hose with a fish bubler (for filtration) on the TB port and it seems to be fine. Going to take it for a drive in a bit to see what happens. So I guess I am left with 2 options. EGR rebuild of EGR delete. No smog test here so no one would notice the deletion unless they are looking for it.
Opinions? Pros and cons? I know, this just became another thread that has probably been discussed at length with the die hard EGR and anti-EGR peeps.
For ˟˟˟˟s and giggles with it off I tried to suck air through the hose as I throttled up (ya gotta die from something). The engine immediately dies. So I am assuming that when the TB needs air from that port at the specific rpm range, the EGR is not giving it and causes the engine to stumble but not shut down (much lighter vacuum than my sucking). So I put a screw in the existing hose leading to the EGR, put another hose with a fish bubler (for filtration) on the TB port and it seems to be fine. Going to take it for a drive in a bit to see what happens. So I guess I am left with 2 options. EGR rebuild of EGR delete.
tried to suck on exactly which hose? the tb port needs to be blocked off, then put a vacuum hose on the top port of the egr, and suck on it while the engine is running, the motor should die or be rough, which indicates that the egr valve is working.
put a bolt in the end of that big hose that has the fish bubler on it.
tried to suck on exactly which hose? the tb port needs to be blocked off, then put a vacuum hose on the top port of the egr, and suck on it while the engine is running, the motor should die or be rough, which indicates that the egr valve is working.
put a bolt in the end of that big hose that has the fish bubler on it.
So that last vacuum port on the TB connects via vacuum tube to the vacuum rail which runs to the back of the engine then via another tube to the EGR valve (I just learned this is wrong). At about 2500 or so RPMs, that port sucks air. The EGR was not giving any air. In fact, the combination of pulling air from the EGR and no air into that TB port causes the stumble. If I blocked of that TB port and advance the throttle, I get a similar stumble. I added a new tube with a filter on that TB port and it runs perfectly.
I looked up some diagrams to find out the names of these ports to make more sense. Turns out this port may should have been connected to the canister, not EGR valve.
The previous owner replaced the rail and lines. I think he jacked it up quite a bit.
It seems the TB port in question should go to the rail to the back of the engine, then tube to the charcoal canister NOT THE EGR. Since it does go the the EGR and there is already something going to the canister, that means that in addition to that TB port being wrong both of these other lines are wrong.
I have a job ahead of me sorting all this out.
On the bright side, I have a lot of new solid parts, I know the engine has good compression, TB is clean, complete tune up, etc...
Once I sort this out, I should have a very solid truck.
I added a new tube with a filter on that TB port and it runs perfectly.
opening up ports on the tb is not correct, because it could introduce airflow that wasn't accounted for by the air flow meter, so you need to stop doing that... just plug 'em up.
there should be a vacuum hose routing diagram on the inside of the hood, the smog guys use it.
08-10-2016, 02:03 PM
