suggestions about how to fix idle/ throttle bogging
03-10-2019, 01:13 AM
#1
Registered User
Thread Starter
Join Date: Oct 2016
Posts: 12
Likes: 0
Received 0 Likes
on
0 Posts
suggestions about how to fix idle/ throttle bogging
Hi and thanks for clicking, I am super grateful for all the knowledge on this forum. hoping you guys can help give me a couple suggestions of where you would start if you were me and you had to fix your rig.
SKIP THIS PARAGRAPH IF YOU WANT READERS DIGEST VERSION
or continue on the line below if you would like to hear me ramble.
truck is an 88 california pickup, 5spd manual 2.4 L 2wd 22r. its got about 180k miles on it and has been nothing but reliable since i bought it around 80k ago.
last year in May it started running rough and so I decided i would do all the maintenance id been neglecting. drained the oil and when i pulled the radiator cap off in preparation to drain the coolant, a spurt of oil came out the oilpan drain plug. perfectly in sync with when i introduced air to the cooling system.
I figured this meant head gasket was blown, so i tore the whole thing a part, indeed it was blown, and at this point i got overwhelmed with work and other life stuff.
Fast forward to now, I put the engine back together after placing the head gasket, with intention of selling it since i had bought a new truck. Then i decided to keep it and use it for work since new truck was too clean (im a painter, cab interiors get jacked up real quick) Since i was going to be keeping it i figured i better bite the bullet and do the timing chain before getting it back on the road.
Last week I finished that.
Now the truck is all assembled (new parts included plugs, wires, distributor cap, fuel pump, air filter, battery terminals, timing chain, timing chain cover& guides, cam sprocket, oil pump, water pump, rocker arm adjustment screws, all 3 belts) except air filter housing which i have pulled at the moment and reliably fires right up again however it doesn't want to run if you touch the gas pedal or throttle. As soon as you let off the gas it begins bogging down and dies a slow and painful death. fires up again immediately and will idle at high rpms but continues to die immediately following even just the slightest pressure applied to gas pedal. I'm no genius, but it seemed to me like it must be related to the fuel flow into the carb or possibly a problem with the choke. I poked around at the butterfly valves like an idiot (literally just poked them with my pointer finger) before realizing I know very little about my carbs anatomy and looked for something else to blame. I did notice that the fuel level in the sight glass was nearly at the top. This lead me to believe the truck was flooding. I bought a new fuel pump realistically because its cheap and easy to "rule out". after installing it AND starting the engine i noticed somehow my spacer never made it back on and the new pump was bolted directly to the head. If the fuel pump was installed without spacer then theoretically the arm that operates the pump would be receiving much more pressure every rotation of the camshaft, and thus pumping more gas to the carb, right? Did i damage my fuel pump by running it like this for 30-45 seconds? I made a new spacer now and have reattached the same fuel pump. it seems to work fine because i can still start the car and it will idle as long as I don't touch the gas pedal.
my next idea is that it is a vacuum leak somewhere or perhaps the intake is drawing air from somewhere and is cracked? i understand an unlit propane torch is the way to test this, I will try this later today after i go to bed and then wake up. i also need to double check all vacuum connections vs a diagram to ensure proper routes. while i am speaking of vacuum lines i should mention that the three prong bvsv located between the intake and valve cover was broken and is missing the top hose fitting. The vacuum line that ought to attach here has been plugged and that was 30k miles ago.
my last and hopefully wrong theory is that I've got a carb problem. given the delay in finishing the head gasket job the carb has been sitting almost a year. I have sprayed the hell out of it with carb cleaner and monkied around with its various mechanisms and levers. why? i don't know i guess i thought maybe the choke was stuck potentially or the float was stuck? regardless I can assure you all moving external mechanisms do indeed move, i fumbled around with them awkwardly like a prom date. the fuel level in the sight glass seems to be slightly below midway now where I would like it to sit but i think i know how to adjust that. Mix screw on passenger side of carb? it has a Phillips head? I also saw that there was a buildup of somme oranges residue on the outside of what i believe is a jet in the choke breaker diaphragm? i scraped it off carefully. the only other pertinent piece of info I can tell you is that it seems like there is a good amount of fuel coming out the tail pipe while the truck idles.
I will update as I try things but would love advice from anyone who has experience with a situation of this nature. the following is a list of questions I have thought too hard about, and you will probably know the answers to, thanks in advance!
If the truck can idle for extended periods wouldn't that indicate the fuel pump and fuel lines and fuel filter are not at fault? and wouldn't it suggest that the carb is not gummed up or blocked?
Is there a different "port" that fuel is fed thru once you hit the gas pedal once? something changes in the way the car operates obviously because all cars idle drops after touching the accelerator.
Could this somehow be a timing issue?
Could this be due to damage i may have done to fuel pump prior to making the 1/4 inch spacer? if so how do I test the pump?
Could this somehow be related to belt tensioning?? cause i know i aint got that dialed in yet
does fuel coming out the exhaust suggest a valve problem?
P.S. whoever posts the solution I am going to send a present to, and it will be something cool!
SKIP THIS PARAGRAPH IF YOU WANT READERS DIGEST VERSION
or continue on the line below if you would like to hear me ramble.
truck is an 88 california pickup, 5spd manual 2.4 L 2wd 22r. its got about 180k miles on it and has been nothing but reliable since i bought it around 80k ago.
last year in May it started running rough and so I decided i would do all the maintenance id been neglecting. drained the oil and when i pulled the radiator cap off in preparation to drain the coolant, a spurt of oil came out the oilpan drain plug. perfectly in sync with when i introduced air to the cooling system.
I figured this meant head gasket was blown, so i tore the whole thing a part, indeed it was blown, and at this point i got overwhelmed with work and other life stuff.
Fast forward to now, I put the engine back together after placing the head gasket, with intention of selling it since i had bought a new truck. Then i decided to keep it and use it for work since new truck was too clean (im a painter, cab interiors get jacked up real quick) Since i was going to be keeping it i figured i better bite the bullet and do the timing chain before getting it back on the road.
Last week I finished that.
Now the truck is all assembled (new parts included plugs, wires, distributor cap, fuel pump, air filter, battery terminals, timing chain, timing chain cover& guides, cam sprocket, oil pump, water pump, rocker arm adjustment screws, all 3 belts) except air filter housing which i have pulled at the moment and reliably fires right up again however it doesn't want to run if you touch the gas pedal or throttle. As soon as you let off the gas it begins bogging down and dies a slow and painful death. fires up again immediately and will idle at high rpms but continues to die immediately following even just the slightest pressure applied to gas pedal. I'm no genius, but it seemed to me like it must be related to the fuel flow into the carb or possibly a problem with the choke. I poked around at the butterfly valves like an idiot (literally just poked them with my pointer finger) before realizing I know very little about my carbs anatomy and looked for something else to blame. I did notice that the fuel level in the sight glass was nearly at the top. This lead me to believe the truck was flooding. I bought a new fuel pump realistically because its cheap and easy to "rule out". after installing it AND starting the engine i noticed somehow my spacer never made it back on and the new pump was bolted directly to the head. If the fuel pump was installed without spacer then theoretically the arm that operates the pump would be receiving much more pressure every rotation of the camshaft, and thus pumping more gas to the carb, right? Did i damage my fuel pump by running it like this for 30-45 seconds? I made a new spacer now and have reattached the same fuel pump. it seems to work fine because i can still start the car and it will idle as long as I don't touch the gas pedal.
my next idea is that it is a vacuum leak somewhere or perhaps the intake is drawing air from somewhere and is cracked? i understand an unlit propane torch is the way to test this, I will try this later today after i go to bed and then wake up. i also need to double check all vacuum connections vs a diagram to ensure proper routes. while i am speaking of vacuum lines i should mention that the three prong bvsv located between the intake and valve cover was broken and is missing the top hose fitting. The vacuum line that ought to attach here has been plugged and that was 30k miles ago.
my last and hopefully wrong theory is that I've got a carb problem. given the delay in finishing the head gasket job the carb has been sitting almost a year. I have sprayed the hell out of it with carb cleaner and monkied around with its various mechanisms and levers. why? i don't know i guess i thought maybe the choke was stuck potentially or the float was stuck? regardless I can assure you all moving external mechanisms do indeed move, i fumbled around with them awkwardly like a prom date. the fuel level in the sight glass seems to be slightly below midway now where I would like it to sit but i think i know how to adjust that. Mix screw on passenger side of carb? it has a Phillips head? I also saw that there was a buildup of somme oranges residue on the outside of what i believe is a jet in the choke breaker diaphragm? i scraped it off carefully. the only other pertinent piece of info I can tell you is that it seems like there is a good amount of fuel coming out the tail pipe while the truck idles.
I will update as I try things but would love advice from anyone who has experience with a situation of this nature. the following is a list of questions I have thought too hard about, and you will probably know the answers to, thanks in advance!
If the truck can idle for extended periods wouldn't that indicate the fuel pump and fuel lines and fuel filter are not at fault? and wouldn't it suggest that the carb is not gummed up or blocked?
Is there a different "port" that fuel is fed thru once you hit the gas pedal once? something changes in the way the car operates obviously because all cars idle drops after touching the accelerator.
Could this somehow be a timing issue?
Could this be due to damage i may have done to fuel pump prior to making the 1/4 inch spacer? if so how do I test the pump?
Could this somehow be related to belt tensioning?? cause i know i aint got that dialed in yet
does fuel coming out the exhaust suggest a valve problem?
P.S. whoever posts the solution I am going to send a present to, and it will be something cool!
03-10-2019, 03:58 AM
#2
I did notice that the fuel level in the sight glass was nearly at the top. This lead me to believe the truck was flooding
03-10-2019, 06:02 AM
#3
Registered User
If your convinced is a fuel problem... pinch the fuel line with a pair of vice grips to reduce NOT stop thre flow of gas... see if that makes a difference... thus a carb problem possible if it does...
I'd also double check the timing...
I'd also double check the timing...
03-10-2019, 04:27 PM
#6
Registered User
Thread Starter
Join Date: Oct 2016
Posts: 12
Likes: 0
Received 0 Likes
on
0 Posts
negative, its the stock aisin
pinching fuel line does not affect it however i did get the truck running for a good 5 min. it seemed like one of the butterfly valves (on the right) was stuck open so after some more groping with the little levers on the back i got it closed. I noticed also when first trying to start the truck as soon as I would take my foot off the clutch it would seem to bog down.
after getting it going for about 5 min there was a decent amount of smoke coming from somewhere or potentially multiple places. appeared to be near where the exhaust manifold flange bolts to the exhaust pipe and where the oxygen sensor bolts in
pinching fuel line does not affect it however i did get the truck running for a good 5 min. it seemed like one of the butterfly valves (on the right) was stuck open so after some more groping with the little levers on the back i got it closed. I noticed also when first trying to start the truck as soon as I would take my foot off the clutch it would seem to bog down.
after getting it going for about 5 min there was a decent amount of smoke coming from somewhere or potentially multiple places. appeared to be near where the exhaust manifold flange bolts to the exhaust pipe and where the oxygen sensor bolts in
03-11-2019, 05:17 AM
#7
Registered User
Start it with the clutch bypass switch...
what kind of smoke? Burning oil? Steaming coolant?
block the rear end up and see if the wheels are still turning with the clutch engaged...
your clutch may NOT be releasing...
thinking outloud... not sure why that would have anything to do with it bogging down when you let off the clutch though...hmmm?
what kind of smoke? Burning oil? Steaming coolant?
block the rear end up and see if the wheels are still turning with the clutch engaged...
your clutch may NOT be releasing...
thinking outloud... not sure why that would have anything to do with it bogging down when you let off the clutch though...hmmm?
Last edited by 87-4runner; 03-11-2019 at 05:25 AM.
Trending Topics
03-24-2019, 09:33 AM
#8
Registered User
Thread Starter
Join Date: Oct 2016
Posts: 12
Likes: 0
Received 0 Likes
on
0 Posts
sorry ive been MIA I appreciate your advice and suggestions 87-4runner
Since i posted this i found that the secret bolt in the head holding it to the timing cover never was tightened, and it made me begin to have my doubts about the quality of the work when the timing chain was replaced.
I didn't want to complicated the story any further in the original post but what really happened was my uncle needed some work and so i hired him to replace the timing chain since it was taking me forever to find enough time to get it done.
I guess he aint what he used to be with a motor, that or he just didn't care since it wasn't his car but the take home is he did a really lousy job. gasket sealer all over the timing cover, oil leaking from the front of the head, not to mention he didn't actually finish the job entirely.
So i decided i was going to just start from scratch and i tore the engine back down to the block. Re-did the head gasket, replaced some studs in the exhaust side of the head, Made plates for the egr and decided to remove that in hopes that it would eliminate the possibility of the stumbling idle and stalling being due to a vacuum leak. READJUASTED THE VALVES my god did he have them off! way too tight! Now ive got the engine back together it fires up nicely and ive gotten it to run but the smoke does still seem to come from the exhaust flange its exhaust really i think the thing has a decent leak at the flange. maybe this is causing the truck to stall?
The fuel level in the carb is a little low but not far from where it ought to be. I read another thread on here that suggested the throttle positioner or dashpot? im not sure, there are so many different potential suspects that I am not sure where to start. The idle is ok cold but definitely begins to struggle as things heat up.
Since i posted this i found that the secret bolt in the head holding it to the timing cover never was tightened, and it made me begin to have my doubts about the quality of the work when the timing chain was replaced.
I didn't want to complicated the story any further in the original post but what really happened was my uncle needed some work and so i hired him to replace the timing chain since it was taking me forever to find enough time to get it done.
I guess he aint what he used to be with a motor, that or he just didn't care since it wasn't his car but the take home is he did a really lousy job. gasket sealer all over the timing cover, oil leaking from the front of the head, not to mention he didn't actually finish the job entirely.
So i decided i was going to just start from scratch and i tore the engine back down to the block. Re-did the head gasket, replaced some studs in the exhaust side of the head, Made plates for the egr and decided to remove that in hopes that it would eliminate the possibility of the stumbling idle and stalling being due to a vacuum leak. READJUASTED THE VALVES my god did he have them off! way too tight! Now ive got the engine back together it fires up nicely and ive gotten it to run but the smoke does still seem to come from the exhaust flange its exhaust really i think the thing has a decent leak at the flange. maybe this is causing the truck to stall?
The fuel level in the carb is a little low but not far from where it ought to be. I read another thread on here that suggested the throttle positioner or dashpot? im not sure, there are so many different potential suspects that I am not sure where to start. The idle is ok cold but definitely begins to struggle as things heat up.
03-24-2019, 09:41 AM
#9
Registered User
Thread Starter
Join Date: Oct 2016
Posts: 12
Likes: 0
Received 0 Likes
on
0 Posts
oh also, maybe this is pertinent to someone:
When I was setting the timing and turning over the engine by hand i was kind of surprised at how tight it felt. yes i know i had the plugs in but ive turned it over by hand with them in plenty of times before. and it seemed like it was fighting a little bit of resistance?
i know, im a mess, im sorry, please help a poor fool get his yota back on the road for summer
When I was setting the timing and turning over the engine by hand i was kind of surprised at how tight it felt. yes i know i had the plugs in but ive turned it over by hand with them in plenty of times before. and it seemed like it was fighting a little bit of resistance?
i know, im a mess, im sorry, please help a poor fool get his yota back on the road for summer
Thread
Thread Starter
Forum
Replies
Last Post
JakeBhs09
95.5-2004 Tacomas & 96-2002 4Runners
29
05-05-2011 09:43 AM
JollyGreen
86-95 Trucks & 4Runners
9
11-25-2009 07:42 PM
