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Getting Desperate - backfire/popping from intake

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Old 07-05-2012 | 10:37 AM
  #41  
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Originally Posted by Kiroshu
You can tell if your exhaust is restricted very quickly with the vacuum gauge.

Hook up gauge and run the engine at 2k rpms and if the vacuum drops to zero or close to zero you have a resrticted exhaust.

vacuum holds steady does not drop when accelerator held at 2k rpms.

also i think i found a hairline crack on the exhaust manifold just above the O2 sensor.
Old 07-12-2012 | 03:00 PM
  #42  
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fuel pressure gauge has been reading about 29psi at idle now.

new denso fuel pump going in today, keeping my fingers crossed. I need to get this truck to the smog station.
Old 07-12-2012 | 03:22 PM
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Originally Posted by budgetbuilder
thanks.....will try that tonight.

is it common for the vacuum advance diaphram to leak? I sprayed carb cleaner all over it and no difference.
If you have a 22RE, then your distributor does not have a vacuum advance on it. The ignition advance is controled by the computer.

Only the 22R carburated engines had a vacuum advance. So if you have a vacuum advance distributor on your 22RE, its the wrong distributor.

Last edited by myyota; 07-12-2012 at 03:25 PM.
Old 07-14-2012 | 03:55 PM
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Originally Posted by myyota
If you have a 22RE, then your distributor does not have a vacuum advance on it. The ignition advance is controled by the computer.

Only the 22R carburated engines had a vacuum advance. So if you have a vacuum advance distributor on your 22RE, its the wrong distributor.
myyota you are correct, that actually was the power steering vacuum valve.

The new denso fuel pump is in and it has made no difference, the only thing this did was tell me the old fuel pump was perfectly fine.

For documentation purposes the new fuel pump was pushing 29-30psi at idle.

Unsure where to check next..... Guess i'm gonna get a few more cans of carb cleaner and spray away with hopes of finding a

FPR?
Auxillary Air Valve?

Last edited by budgetbuilder; 07-14-2012 at 03:59 PM.
Old 07-18-2012 | 10:03 AM
  #45  
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questions on jumping chains...

does it jump under load or at start up?

if a chain is loose enough to jump a tooth why doesnt it just keep jumping until the timing is so off it wont run/start?

is there an audible sound when the chain jumps, is there a noticeable engine jerk?

I noticed when i set the timing to 0 at the crank, the cam gear mark was at 12 o'clock, the distributor rotor was pointing a few degrees after the cyl 1 point on the cap. Is that right?

didnt look right to me so i took the distributor out and moved it back a tooth but the truck wouldnt start. So i put it back the way it was.

Last edited by budgetbuilder; 07-18-2012 at 10:04 AM.
Old 07-19-2012 | 06:05 AM
  #46  
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You mentioned a crack in your exhaust manifold? If that is so that more than likely could be your "poping" under acceleration. A manifold leak on any engine makes alot of noise and poping. I would look further into that. Plus exhaust leaks at manifolds create a power loss especially for the 22r.

If the timing chain was jumping you would notice an extreme difference in engine performance. It would run poorly and possibley not at all. And if thats the case then the timing chain you be making alot of noise. "Rattle from front of engine."

And yes 22r Top dead center cyldiner # 1 ready to fire is:

Distributor rotor pointing at # 1 on the Distributor Cap.

Camshaft sprocket timing mark at 12 o'clock.

Crankshaft sprocket timing mark at 6 o'clock.

Crankshaft pulley mark at 0.

Cylinder #1 both valves closed ready to fire.

Last edited by Kiroshu; 07-19-2012 at 06:08 AM.
Old 07-25-2012 | 09:18 PM
  #47  
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update... took the valve cover off again and pulled the distributor. Turned the engine over by hand and watched all rockers go up and down on the cam shaft bumps, everything seemed to be working correctly just by eyeballing it. I then set the valve lash back to .007 intake and .011 exhaust (cold). I turned the engine until i got it back to 5 BTDC. I then installed the distributor half way and moved the rotor to 12 o'clock, as i pushed it in the rest of the way it lined up to cyl 1 on the distributor cap on its own.

i also did the heat shrink on the dipstick trick to ensure no leaks.

put everything back together and started her up. Started up first try and the motor sounded a bit different, sounded stronger....i let it warm up a bit and then revved it up slowly and it didnt pop. i revved it up fast and its popping still. I heard a vacuum leak and found that i had forgotten to install the line on the EGR. Put it in and the engine sounds pretty solid now at idle but im still getting the popping when accelerating. I put the jumper and set the timing to 5 BTDC. When i took the jumper out the timing was at about 12 BTDC where previously it would go back to 0 TDC with jumper removed.

Either way motor sounds a bit more solid at idle now.

I stood there and stared at the motor...............i pull out my 4crawler TPS adjusment instructions and thats when i noticed...

Table 1: 22RE (2.4L-4 cyl) - TPS Adjustment Specifications
- Early model p/n: 89452-20060
- Late model p/n: 89452-12040

The TPS i have in there is p/n89452-20050, could i have the wrong TPS??

I then found this thread http://forums.club4ag.com/zerothread?id=65337 about half way down someone compared the 2 TPS sensors and they seem to have different resistance and different mechanisms.

From what i've found the original TPS for an 87 4runner 22re should be p/n 89452-28010 (interchange 89452-20060)

am i on to something or am i just getting more desperate....

Last edited by budgetbuilder; 07-26-2012 at 08:08 AM.
Old 07-29-2012 | 04:04 PM
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You ever address the exhaust leak near your oxygen sensor....? More than likely could be the popping.
Old 07-30-2012 | 09:13 AM
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i took another look at that, I thought it was leaking because i saw some faint smoke coming from that area with hard revving but i have not been able to replicate. The popping is definately coming through the intake. its echoing through the air filter box and i can hear the flapper in the AFM when it pops.

Was talking to a buddy of mine and he mentioned maybe the mechanical advance in the distributor may be faulty.....do the 87 4runner EFI's have mechanical advance? is there a way to test?
Old 08-09-2012 | 10:43 AM
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update....
-Confirmed the spark plugs were gapped to 0.31 per FSM
-All 4 plugs were carbon fouled
-Air gap in distributer is off by 0.15mm (FSM range is 0.2mm – 0.4mm and mine was at 0.55mm)
-Getting trouble code 11 now (which is probably a result of me opening up the TPS sensor and siliconing it back together) the original TPS is now a paper weight. As a result of this, my jumper is no longer working when trying to set the timing, I guess its not getting IDL signal to the ECU anymore.

Am now looking to replace TPS, Distributor, Ignitor and plugs

Last edited by budgetbuilder; 08-09-2012 at 10:44 AM.
Old 08-23-2012 | 08:41 AM
  #51  
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for documentation purposes:

swapped in a different igniter w/coil from a running truck and did not fix the problem.

I have a distributor coming so i'll try that and report back.
Old 08-28-2012 | 08:50 AM
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well swapped in a used distributor with the air gap within FSM specs. Still getting the pops through the AFM.

Last edited by budgetbuilder; 10-10-2012 at 12:26 PM.
Old 09-28-2012 | 09:21 AM
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ok so i replaced the PCV valve....the original grommet was toast. After i removed the PCV (which was a PITA) i tested it and it appeared good.

Anyhow, for safe measure installed a new PCV and new grommet.

Checked codes again...still pointing to the TPS.

I've bit the bullet and purchased a new TPS, will be installing this weekend...will post back results!
Old 10-04-2012 | 08:55 AM
  #54  
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update....still poppin! lol

new tps installed now too....

maybe my stubborness is not allowing me to give in and take it to a shop. Im going to replace the engine control temperature sensor (aka coolant temp sensor) with a new factory Toyota sensor next.

the temperature gauge on the truck has always jumped to the middle everytime the truck is started, whether its cold or hot. Im thinking this may have some relation to my problem.

I found a thread that fixes the gauge problem.

https://www.yotatech.com/forums/f116...inally-218848/

i will pull the cluster and fix the gauge problem and install the new sensor and see where that gets me! Wish me luck

Last edited by budgetbuilder; 10-10-2012 at 12:26 PM.
Old 10-17-2012 | 03:50 PM
  #55  
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looks like i've lost my audience! ha

anyhow for the purpose of documentation...

cluster temp gauge is fixed!

new ECT installed. No Difference.

installing another Denso O2, i tested the other one through the diagnostic port with jumper in place and didnt get any fluctuation the reading stayed at .2

also the wires that run across the manifold to the igniter had wire loom that was somewhat melted and had lots of electrical tape on it. So i decided to unwind all that tape and removed the loom. Wiring was brittle and had the infamous green mold stuff on them, one wire pulled apart as i was taking the tape off. Im going to replace about a 12" section of all 3 wires. Im now wondering if my injector wires are the same, i guess i'll start unwrapping all tape and check the injector wiring "butts".

Last edited by budgetbuilder; 10-17-2012 at 03:52 PM.
Old 10-17-2012 | 07:58 PM
  #56  
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wow...you've tried lots of stuff. I hate problems like this.

Watch your vaccum gauge when it starts popping. My logic says if its backfiring through the intake, your gauge will jump around during said backfires, and if it doesn't jump around, maybe your looking in the wrong places. Now I ain't no mechanic but I figure it makes sense.
Old 10-22-2012 | 01:38 PM
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thx nothingbetter will check that.

i took a trip to my local yard this weekend and scored a ECM out of an 86 4runner and i took the wiring connector to the igniter.

also took the EFI sensors out of an 85 celica. This makes up for the last few wasted trips.
Old 11-12-2012 | 06:02 PM
  #58  
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Been super busy lately and haven't had a chance to mess with it in a few weeks but today I limped it into the driveway and removed the upper plenum and the electrical tape around the harness. Checked the fuel injector "butts" and they looked really good. I was somewhat dissappointed because I really was hoping to find a broken wire or 2.

What I did find though was intake runners 1 & 2 were wet with what appeared to be fuel and oil, I say oil because it was dark in Color but I guess it could of been fuel and carbon.

Anyhow intake runners 3&4 were bone dry.

Can someone tell me why that is?
Old 11-12-2012 | 06:37 PM
  #59  
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From: 46 50' 36.82'' N 122 19' 41.01'' W
Becuase the intake valves that belong to those cylinders 3 & 4 are not closing all the way, or on time. The backfiring is cleaning the intake.
Old 11-12-2012 | 06:49 PM
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So there should be fuel puddled in the runners?

Any good tips on adjusting those intake valves as I have adjusted them valves to. 008 multiple times and rechecked hot and cold?


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