sinful

The motor has a slight shake at idle and the gas mileage isn't as good. What could it be? I have to adjust the idle a bit higher than normal so that the engine doesn't shake. Under acceleration the shake goes away and it runs smooth. And when driving everything seems normal except I'm getting about 20 mpg and is a 2WD pickup.

Upon researching the issue I came across a similar post and the guy posted a video of the engine and we are having the exact symptoms

http://www.youtube.com/watch?v=GnPu3...e=channel_page

sinful

I'm suspecting a miss fire from a bad injector. but would hate to take apart the intake just to get the injectors and find out it's not the injectors.

Has anyone ran into a similar issue?

Bassmastry101

iTrader: (1)

From the description it sounds like a misfire. Have you checked the timing? Make sure all the plug wires are making a good connection or just replace them if its time.

Not sure about a 2 wheel drive, but 20mpg is about right for a 22re.

If you do happen to get the injectors out, you can always send them off and have them cleaned/rebuilt. That isn't too expensive, but your truck would be down for a week or so.

cman1

iTrader: (1)

when was your last real tune-up? seafoam treatment,cap,rotor, plugs, wires.

sinful

I bought the truck 3 months ago and only did spark plugs and air filter. the spark plug wires looked good but it's probably a good idea to check the resistance with a multimeter (didn't have one before but now i do) since I'm very limited with funds to just throw parts at it. I really just want to diagnose the problem. I have the necessary tools to diagnose and repair.

But the key here is the miss only happens at idle. If I lower the RPMs slightly below normal, the shake get's worse. If I turn the AC on, the shake get's even worse at idle (the AC on is not making the RPMS go up but thats awhile different problem). but my point is the AC on puts more load at idle and makes the miss worse for some reasson. However if I maintain the truck let's say above 1100 rpms at idle, no miss and no shakes. Also no miss/shakes when driving at all speeds so long as I'm pushing the gas. And if I let go the gas while cruising in gear at low rpm, every once in awhile it does feel like slight jerk or hasitation.

sinful

as far as the mpg, I do feel like I'm missing at least 5 mpg. aren't these 2wd trucks with stock tires supposed to be getting 25+ mpg?

it's using almost a full tank of gas for 280km road trip. Whats that in miles............173 miles.

whats the tank capacity? maybe I'm wrong

alltracman78

To check for a misfire you can pull the plug wires one at a time.
The cly that is running worse will have the least effect on the idle when you pull the wire.

You can also take a look at your O2 signal. A misfire will give you a lean condition, so the O2 should be staying more on the lean side [below .45V].

You may also have a small vacuum leak.

sinful

those are great ideas. i will try them.

i should be able to splice into the o2 sensor with my multimeter easily?

alltracman78

Don't damage the wire, if you don't have a DIAG box in your engine bay, you can put your positive lead into the rear of the ECU connector where the metal pin is.
Find a good ground for your negative.

Bassmastry101

iTrader: (1)

The VSV on top of your valve cover is supposed to idle up the engine when the AC is on. If it's not then that could be part of your problem. Check your vacuum lines for leaks and cracks. Easy way to do that is spray some carb cleaner on the lines while the engine is running. If it idles up then you have a leak.

There is a diagnostic plug near the driver side fender for your o2 sensor. It should be in with the group of plugs for your check engine light and fuel pump test connections.

sinful

I do have the diag box. I´m not understanding ¨the positive lead into the rear of the ECU connector or find a good ground¨ thing. where.. off the o2 sensor? sorry I´m not following.

sinful

I tried messing with this awhile ago trying to bring up the RPMs with the AC on. I turned the screw thats on the VSV and the RPMs did move up with the AC on. But then it stopped responding for odd reason. you think this might be related to my problem_?

sinful

By the way I did remove one spark plug wire at a time with the engine running. Every single cyl seemed to respond by disconnecting and reconnecting the spark wire.

And I went a little further...

I checked the resistance on each spark plug wire. I got 1.5xx ohms on all wires. The wire from the coil to the distribuitor had a little bit more resistance 1.720 ohms. I also found some rust in the wire lead to the coil. And another wire lead to the distribuitor had rust.

Cleaned everything pretty good. Remove the distribuitor cap, cleaned the 4 post leads, center lead, rotor leads, and added electric grease on all the spark plug wire lead ends. probably not the best thing to do compared to replacing with new parts but like I said...funds are low. plus is fund to play with this.

so overall for some odd reasson im noticing the engine running a bit smoother after all this cleaning. but will need to drive some more to know for sure if this had any impact on the idle miss fire.

sinful

okay so the miss came back. did some more inspection. noticed the intake tube clamps/screws were very loose on both ends at the TB and MAF box. I probably forgot to tighten them last time the MAF box was removed. tightened those up pretty good. also the one of the vacuum hoses that goes from the TB to the AC valve regulator had cracks. replaced that. messed with the TB air screw thing to fine tune the idle rpm with or without AC.

seems to be runing okay now once again.

Another thing I noticed is when the AC is on, the VSV makes a vacum leak noise. shhhhhhhhhhh. is this normal?

sinful

is the VSV an electronic valve thats on the valve cover, that brings up and down the rpms according to the AC/compressor needs?

Bassmastry101

iTrader: (1)

Yes I believe so. I had mine working great after my build but then I changed heads and never took the time to get it working again. I'm sure that is what it does. Someone will correct me if I'm wrong.

Mason155lbs

So did u fix the problem?? cause mine is doing that too!!

LauraLuvsHerLilTruck

I have a '93 22 RE 2WD. I get about 22 mpg around my rural dirt roads or in town, and around 28 on long freeway road trips.

Co_94_PU

iTrader: (-1)

You missed try again.

LauraLuvsHerLilTruck

What did i do wrong? Duh... i don't see... i was responding to the original post by Sinful, and a couple of comments that came after regarding his gas mileage in a 22 RE 2WD.