Engine bogs and will not accelerate?

Hi,

Is the check engine light staying on when the engine is running? If it is, we need to start by checking for diagnostic trouble codes. Here is a quick video showing how that is done:

https://youtu.be/b2IJGfImVvw

If there is no light staying on, then it could be a few different things. For example, low fuel pressure, an engine vacuum leak, a partially plugged catalytic converter. Here is a link that shows how to check for a vacuum leak. Try this first.

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

If there are no leaks, then I would suggest checking fuel pressure. Here is a link for that:

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

If that is good, then inspect/check the catalytic converter. Here is a link that shows how to do that as well. In addition, I attached a link explaining the common symptoms of a converter issue.

https://www.2carpros.com/articles/bad-catalytic-converter-symptoms

https://www.2carpros.com/articles/how-to-test-a-catalytic-converter

Let me know if this helps or if you have other questions. Also, let me know if the engine is back firing, producing an odd odor, have an odd sound, or anything you can think of that may help me diagnose the issue.

Take care,
Joe

Well, let me give you some history. Bought the truck last year ran fine until about June then had issues with it shutting off. replaced the fuel filter pump, pressure regulator, TPS sensor and control module, fuel pump twice as I got a bad one. starts and runs fine but loses power on inclines. Doesn't make any funny sounds or backfires. Service engine soon light has been on since day one and never checked for codes. i am thinking vacuum leak or mad sensor but haven't sprayed carburetor cleaner yet. exhaust doesn't seemed plugged.

also a funny thing, on the way home tonight i had the heater on and set to floor with fan on 3. when i came up on a hill and crowded the gas i got lots of air flowing out of the upper vents and when i let off it went away. i'm sure the air flow door is operated by vacuum which is why i think it might be a leak somewhere.

Hi,

Absolutely. There wasn't enough vacuum to maintain airflow direction, so you have a leak at some point.

This is from the manual:
Mode Control

The mode rotary control knob operates a rotary vacuum switch that rotates engine vacuum to specific hoses in the vacuum harness. These hoses control various vacuum actuators on the HVAC system. Each actuator operates an air valve (a door-like hinged deflector) that routes the air to the various outlets as indicated by the symbols on the faceplate.

Try using the link above for locating a leak. Let me know what you find. Also, I attached a pic below of the mode door actuator. It's mounted on the heater box/module.



Joe

okay, so i sprayed carburetor cleaner everywhere and no difference on RPM. tore the dash and glovebox out along with the heater control module. doesn't seem to be anything out of sorts. I bought a code scanner but it will not function when i hook it up. could there be a fuse blown preventing this? i hooked it up to my Toyota Rav 4 and it worked fine. at my wits end on this piece of junk!

I did notice that while going up hills and crowding the gas pedal it sounds like there is no cover on the throttle body.

Hi,

Yes, there could be a blown fuse. Take a test light and see if there is power to pin 16 in the data link connector (DLC). If there is, then I need you to confirm ground with a multimeter. You will set it to ohms and see if there is continuity to a known good ground location. See pic 1

Here is a link you may find helpful:

https://www.2carpros.com/articles/how-to-check-wiring

If you look at pic 2, it shows that power to pin 16 on the DLC comes from the same power supply as the cigarette lighter. Pic 3 shows the fuse location. In addition to just checking the fuse, make sure there is power to and from it. Here is a link you may find helpful:

https://www.2carpros.com/articles/how-to-check-a-car-fuse

Let me know what you find.

Take care,
Joe

Oaky Joe, that was the problem (blown fuse) codes came up. 141,200,404 and 405. first place I was going to look was the EGR valve but I cannot locate it. I did find a 5 pin connector dangling at the back of the motor but upon inspection with a mirror and light I cannot see that the EGR valve was removed and covered with a plate. I cleared the codes, took it for a spin and after the engine light came back on I ran another scan and only got the 405.Question is, if the EGR valve has been removed since I bought the truck I'm wondering why the loss of power on inclines suddenly. It has always run strong for a 4 cylinder. This seems to have happened after I changed the oil and filter (which should have nothing to do with it). Any help appreciated.

Hi,

The codes you listed, are they P codes? For example, P0141.

As far as the EGR, it's on the rear of the engine. See the attached picture.

Let me know.
Joe

Yes Joe, they are p codes. As I stated before after I cleared the codes and drove it I rescanned and only got the the p405. Here is a picture of my engine. The EGR seems to have been removed.

Hi Joe, I think I found the problem. My timing chain snapped this morning on my way to work. I'm sure it must have jumped out of time to cause the loss of power. Thanks for your help.

Hi,

Yep, that makes perfect sense. Thanks for letting me know. I don't know if you need them, but here are the directions for replacing the chain and sprockets. The attached pics correlate with the directions. I honestly would replace the sprockets and tensioner while it's apart.

___________________________________________________


1998 Chevy Truck S10/T10 P/U 2WD L4-2.2L VIN 4
Timing Chain & Sprocket Replace
Vehicle Engine, Cooling and Exhaust Engine Camshaft, Lifters and Push Rods Camshaft Gear/Sprocket Service and Repair Removal and Replacement Timing Chain & Sprocket Replace
TIMING CHAIN & SPROCKET REPLACE
REMOVAL PROCEDURE

^ Tools Required
- J 22888 - 20 Crankshaft Gear Remover

pic 1


1. Remove the engine front cover.

NOTICE: When using the crankshaft balancer bolt to rotate the engine, install sufficient spacers on the bolt to prevent the bolt from going to far in the crankshaft and damaging the threads of the bolt.

IMPORTANT: Make sure the camshaft sprocket alignment mark, which is an 8 mm hole, and the stamped circle in the crankshaft sprocket align with tabs on the timing chain tensioner.

2. Rotate the crankshaft until the number 1 piston is at Top Dead Center (TDC) of the compression stroke.

pic 2


3. Remove the camshaft timing chain tensioner bolts.


pic 3


4. Remove the camshaft timing chain, tensioner and camshaft sprocket at the same time.


pic 4


5. Use the J 22888 - 20 in order to remove the crankshaft sprocket.
6. Remove the crankshaft sprocket key, if necessary.

INSTALLATION PROCEDURE

^ Tools Required
- J 5590 Crankshaft Gear Installer

IMPORTANT: If any of the camshaft drive components are being replaced to correct a noise condition, replace all of the components in the camshaft drive system.


pic 5


1. Install the crankshaft sprocket key, if removed.
2. Install the crankshaft sprocket with the timing mark facing away from the engine, using J 5590 and a hammer.
Make sure that the crankshaft sprocket is seated against the crankshaft.


pic 6

3. Compress the timing chain tensioner spring.
4. Insert a cotter pin or a nail into the hole in the tensioner in order to retain the timing chain tensioner shoe.


pic 7

IMPORTANT: Do not tighten the timing chain tensioner bolts.

5. Install the timing chain tensioner.


pic 8


6. Align the crankshaft sprocket timing mark, the stamped circle, with the tab on the timing chain tensioner.
7. Align the camshaft sprocket timing mark, the 8 mm hole, with the tab on the timing chain tensioner.
8. Install the camshaft sprocket and the timing chain.

NOTICE: Refer to Fastener Notice in Service Precautions.

9. Install the camshaft sprocket bolt.
9.1. Tighten the timing chain tensioner bolts to 24 Nm (17 ft. lbs.).
9.2. Tighten the camshaft sprocket bolt to 130 Nm (96 ft. lbs.).


pic 9


10. Remove the cotter pin or nail from the hole in the timing chain tensioner.
11. Install the engine front cover.

________________________________________________

I hope this helps. Let me know how things turn out for you or if you need help.

Take care,
Joe

Hi Joe,

Well, it was the chain tensioner that broke but I replaced everything since I was in there. It fixed the loss of power and also took away the lifter noise that I thought was just worn out parts! Thanks for all your help. You guys are always great!
Take care,
Gil

I drive a 1998 Chevrolet S-10 and all of a sudden like I heard a loud squealing noise coming out from under the front of the vehicle. I've had a tremendous loss in power and find it very difficult even with the throttle wide open to gain any speed at all. More so, when going up hills or mountains. I usually try to have as much speed as possible before starting to climb a hill/mountain bc usually by the time I get to the top I've already shifted down through the gears with the throttle wide open. Once I top the hill/mountain its like a new vehicle going down with no trouble at all gaining speed quickly. The following codes: P0420,P0440,P1133, & P1404 have shown up. Any info would be greatly appreciated. Thanks!

Need to add that squealing gets louder the more the rpm's increase/throttle I give it. Cranks right up no problem & runs fine while idling with very slight uneasiness.

The squealing leads me to believe something has locked up and the belt is slipping (which could cause a power loss), so check that all accessories are turning when the engine is running. Always protect your eyes in case something breaks. Next, the PO420 deals with catalytic converter. Check to make sure it is not plugged. That will cause a huge power loss. The PO440 is an evap code. I don't think that has anything to do with a power loss. However, you should have the evap system fogged to determine where there is a leak. The PO1133 is a code for the heated O2 sensor. The interesting thing about this is it could have set the PO420. Last, the PO1404 is dealing with the EGR (closed pintle position).

So where do we start... First, remove the EGR and clean all carbon from the valve itself and make sure the ports in the intake that where it bolts are open and not clogged with carbon. See if that makes a difference in power. Next, you need a scanner that will read live information. You need to check the O2 sensors while they are working. They should show between .35 volts and .55 volts. If they are beyond that in either direction, they need replaced. If they are good, then the catalytic converter is most likely bad. You can try disconnecting the cat to see if the power is restored. If it is, the converter is spent. It will be a loud ride to test, but if you have no scanner, that is one way to check.

Most of the info you have given me is exactly what my older cousin and I thought when I let him test drive it and I rode alongside this afternoon. At first, the sudden like squealing noise led us to believe a vaccuum hose for the fuel system was leaking and driving caused increased pressure making it get louder. Also, I initially thought it was coming from the left front quarter panel due to having the windows up going down the road and not being able to pinpoint exactly where the noise was coming from, but yesterday I got out with the truck still idling and used a pole to reach up and rev the engine while I laid down on the ground to look underneath and that is how I determined it was not the side quarter panel. Instead, it was the exhaust itself. Sorry this is so long I get to ramblin' and don't get straight to the point. Although, I am getting there. So, please bare with me.
To make this shorter. My catalytic converter has been rattling for a year or more due to the catalytic material broken up inside the converter, but I didn't mind the noise knowing a new converter wasn't cheap having had it replaced already 4 or 5yrs. ago. We figured some of the lose material all of a sudden plugged the hole allowing no escape for the spent fuel. We also figured the squealing noise was coming from a leak I noticed in the actual header pipe and since the exhaust pipe is more than likely plugged by material pressure is building up between the exhaust manifold and the converter as I give it more throttle the exhaust is being forced out of the small leakage area. The more throttle the louder the noise. We are also thinking this could be tricking the computer to thinking the EGR valve is bad when its really just the back pressure in the pipe. Glad to see that you are thinkin' the same thing. Three heads are better than one. My cousin has worked on race cars all his life so that helped as well. Also, wouldn't it be burning a he!! of a lot of fuel as well bc my gas gauge has went down a half a tank or more in three days with only around 100 miles since last fill up. I'm going to let it sit until Saturday now that we all have a good idea at what it could be. Going to unbolt the head pipe from the converter and tie it and the rest of the pipe up out of the way and run it to see what happens. Hopefully, thats it. I'll keep you updated. Your info was/is greatly appreciated. Thanks!

It sounds like you found it. A couple ideas for you to keep in mind. First, if by any chance you still have the receipt for the converter you purchased, call the parts store. Often times they come with a 5 year 50K mileage warranty. You may get lucky and it may be free to replace. Next, when you remove the converter, check to make sure it didn't plug up the muffler. It happens often. Also, if you are removing the Y pipe, you have to remove both sides for it to move. If you plan to remove the exhaust manifold, be careful not to break any bolts. Spray them with penetrating oil a few times and let them sit so it can work. You don't want to break one. If you spray them, clean the manifold off with brake cleaner to get all the lubericant off before running the engine again.

See, I can be wordy too. Sorry mine is so long. I look forward to hearing what you find.

PS: Don't worry about the post being too long. I need to hear everything.

Stuck?
97 s10 2.2 5sp/m
Low power, Poor fuel economy, top speed 65,
Poor acceleration
Idles smooth but at 1000rpm
Revs easy w/o load, no hesitation
Compression: 149, 151, 145, 153.
Vacuum test: stable @ 19hg
Tps, iac, cts, both o2's, fuel pressure: all good
New catalytic converter, fuel filter, air filter, plugs, wires.
Not fouling plugs, Temp stays 190-200
No miss, no codes.
Brakes are good, all wheels turn easily.

check fuel pressure with a gauge should be 41-47 psi any lower replace pump. Key on only also check for a vacuum leak even though it looks fairly well. finally , disconnect converter and see if runs better, may be partially plugged exhaust behind converter.

Fuel pressure is 42 psi.
Vacuum tested - steady @ 19hg when revved drops slightly then climbs to 24hg.
Ran w/o muffler and no change cat is new replaced because old one was gutted causing o2 sensors to have identical reading which causes improper fuel mixture.

are you sure there are no codes like a trans slipping etc? check cam to crank sensor synchronization that could be off. Course you'll need a pro style scanner for that. Other than that I can't think of anything else unless a cam has jumped time or not advancing like it should.

Have a 97 chevy s10. replaced plugs, wires, cat, muffler, and o2 sensor (after cat). have a problem when driving on the highway in fifth gear. when i have it in fifth it has no power i start to drop in speed when i put the pedal down harder it feels like it could be flooding up. i have to drop it back into fourth gear to get any power and speed up. i get nothing out of fifth gear. what could cause this. it has a rough idle as well. 1997 chevy s10 ls 2.2L

what is the fuel pressure???

Roy

fuel pressure is between 41 and 47 psi

when i am driving down the freeway at about 60mph my car starts to have a little vibration on floorboard and a somewhat loud noise to it and my floor board heats up what could the problem be?. ive already had my transmisson serviced and nothing seemed to be the problem and i have spent 1600$ dollars on fixing it since ive bought in in october of 2009. and also when i drive it boggs out when it wants to and then shuts off and i cant seem to find the problem.

Hello,

Sounds like the Cat. Which floor board gets hot?


.

both floorboards get hot but mostly driver side.

[quote:0136688e25="obxautomedic"]Hello,

Sounds like the Cat. Which floor board gets hot?


.[/quote:0136688e25]=,mechanic001]
both floorboards get hot but mostly driver side. and my car is getting worse at dying and bogging out

Does it have Dual Exhaust? If so could be both are going bad. With driver side the worst of the two.

A test to check you can remove the O2 (oxygen sensor) Sensor in front of cat or cats and see how it does. If improves replace cat or cats.


.

Also, the CAT convert has been out for 3 or so years and engine worked fine up to this point. I also had it scan before changing all the parts listed and they were: PO121, PO122, PO171, PO172, PO300, PO404, PO405, PO420 and PI1404, that's why I started changing out parts.

with all these codes and reding your last post check the fuel pressure with a gauge. You should have 41-47 psi if it's below that replace the fuel pump and filter. if this is a pickup it's easier to remove the box ot of theway to do it. if you have 3 guys you can lift the box by hand. then clear all the codes and see what you have next. If you have a k&n type air cleaner clean the maf as these filters tend to put oil on the maf and screw all your readings up. Also make sure your battery is in good shape as this will also screw up al your readings. but if the fuel pressure is low fix the pump first then clear all codes and startover.

one thing i forgot check for vacuum leaks on hoses, etc.

I'll check the fuel pressure and as far as I can tell all the vacuum lines are okay but one thing that I am concerned about is the TBS area behind the TBS is an open space to the left side that I noticed after installing the new one. I checked the manaual and nothing is noted. Is there suppose to be a gasket to cover that open area or is that just the way it is? I did not check it before I removed it but it came off as one piece. Thanks for your help!

you mean the tps, not tbs and it should be unless it's leaking vacuum.

Sorry for the delay to respond back but I had a mechanic check the engine out and he found lifter's on cylinder 1 were bad so he replace all lifters. The engine ran but it kept idleing off. He checked the pcm and it showed tps, he cleared the codes and tested it again and the tps showed up again. He unpluged the tps and it ran okay. I had installed a new tps before the engine work. I took the new-old one back and replaced it with a new AC Delco model and the engine runs good but at times some hesitation. I know the engine has over 200,000 miles but it just don't have the power it had before things started going wrong while still in the high milage numbers. When driving down the interstate at 65 now and I come up on an incline the truck slows down instead of keeping the speed. I also still hear more vacume noise from the engine when accelarating than when all my engine problems started. There has to be something that I've missed or am not aware of that can fix this problem. Any thoughts will help. I'm also thinking that instead of a vacume leak that one of the vacume lines might be clogged. I cleaned the air pliemun and used carburator clean at the vacume ports on top of the air pliemum. I did not disconnect the lines thou. I did install a new set of fuel injectors and gas requlator. I finished filling the tank up with new gas, 14 gallons to a 18 gallon tank. The mechanic did not think it was the gas pump so that has not been changed. I can go on and on but I'm searching for an answer with out having to pay another arm and leg for a almost complete repair, thanks again and just maybe you have the answer or someone you know might have had this same problem and has the solution. Thanks again for your time and help!

Hi,

When you say you hear a vacuum sound louder than before the work was done, where does the sound come from? Is it under the hood or in the vehicle? An engine vacuum leak will usually cause a rough idle or stalling issue, but the power loss is questionable.

Also, a vacuum leak will usually cause a check engine light indicating a lean fuel mixture. Has the check engine light turned on again or are there any known codes?

Here is a link that explains how to locate a vacuum leak. I would try it since you are hearing a sound. Also, make sure nothing between the air filter box and throttle body is loose or disconnected causing a leak.

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

Let me know.

Joe