glassfishy

Popped in a new fuel filter. Good news and bad news. The job wasn't too bad. Bad News. Didn't help! Oh well I can check that one off my list. My dad wants me to check the fuel pump. Here's why I can't see why it would be that (and I'm not a mechanic so it very well could be that): When I first start it up cold and drive it – it drives fine. It begins to have a strong hesitation and won't go after I've driven it for about 3 to 4 minutes. Usually the temp guage has heated up midway. So in my way of thinking if it was the fuel pump wouldn't it do it all the time and not just after I've driven it around awhile. Also, I would think it would be the same scenario for the Fuel Injectors. I would think it would do it at start up also.

Tomorrow I'm going to try cleaning out the throttle body (like in tech write-up). As far as testing and adjusting the throttle body sensor I'm thinking that's out of my range of knowledge. I do OK with mechanical things like unbolt this bolt and rebolt it on another part, but when it comes to fine tuning I'm not so good. I don't even own an ohm meter. I am going to try and read through the post that 4Crawler sent to see if I can tackle it.

Any other ideas. I just hate to take this thing into the shop. It's not even about the money. I feel like I've pulled a freakin engine out of a 91 and replaced it and got it to work and I can't even get another one to run.

Any more ideas I would be forever greatful!!!

glassfishy

Cleaned out the throttle body with some Gumout Throttle Body Cleaner. I followed directions on can and also used a rag to clean out inside throttle body. Didn't really seem to make a difference. Again, it started up and idled just fine. After about 5 minutes of running great the idle gets rough and when I give it gas it doesn't want to go. I'm confuzled!!

callmej75

Check your timing too

4Crawler

iTrader: (3)

With the warm up factor, it could be that the engine is running mostly on the cold start injector and once the engine warms up, that shuts off and so does the engine. Could also be the TPS, you can get an ohm meter for well under $10 (I uses a $2.99 meter from Harbor Freight). Get one and a few resistors (from Radio Shack or shimilar) to practice with, spend 30 minutes learning to use it and have at it. Not sure what the going labor rate is in your area, but around here they hit you up for at least $100 just to pop the hood (any repairs additional), so figure you have that much money to work with getting a few basic diagnostic tools (like a timing light, etc.).

glassfishy

Dude,

That sounds like a plan. I've been meaning to find an Ohm Meter and mess around with it because everytime I see something that says test the resistance I usually just pass over it. I'm off to the store to get me an Ohm Meter. Can you get that at a Yoga Store? j/k
Thanks man!!

glassfishy

OK, This past weekend I had some time to mess with my 94 Runner. I bought me a OHm Meter (which I've never used before) to test it out. Well, a buddy and me started out with a set of feeler guages he had and we couldn't figure out how to get the feeler guages in behind the throttle screw and stop. We started out with Test #1 of the 5 test TPS write-up and I'll be honest I was thoroughly confused as to wheter it was within SPECs. The Cheap OHM Meter (WalMart Special) Only has 2 settings for OhM testing. It has RX1K and RX10. Which one should I be using or is the Meter I got worthless for this type of testing? I really tried to understand the instructions in teh write up on how to read the Ohm Meter, but his meter had settings of 20X, 2x, etc. How does that coorelate to my 1K and 10 settings.

For Example on the first test I believe I was on the RX10 setting and I was getting a 6 on the Ohm Meter Scale. The range was like 280-800. This all makes no sense to me.

One other thing I did notice that I was going to ask you guys about is I unplugged the TPS sensor plug to test the TPS sensor. W got busy messing with something else and started engine forgetting to replug in TPS sensor. The engine ran much smoother and didn't idle down like it did when TPS sensor was plugged in. Should this be the case? If the TPS sensor was bad, would it do this? If TPS sensor was OK, would it still do this?

As Always, Thanks Guys

4Crawler

iTrader: (3)

Likely RX1K is "Reading X (times) 1K (1000)" and RX10 is "Reading X (times) 10). As noted on the how to section of the web page, go to Radio Shack and buy a resistor or two to practice with. If you have a 1000 ohm resistor and you get a reading of 1.0 on the RX1K setting, then you can be confident that 1.0 x 1K is 1000 ohms. A lot easier with one unknown (the meter) than two unknowns (the meter and the resistance). And that same 1000 ohm resistor might read 100 on the RX10 scale, 100 x 10 = 1000. And you'll note I discuss the "X" ranges on that section of the page. "X" = "times", so your RX1K is equal to what I refer to as a 1000X (1000 times) scale and the RX10 is a 10X scale. Its all a matter of taking the reading on the meter and the setting of the scale and multiplying the two numbers to get an actual resistance.

Nothing wrong with a "cheap" meter, I use one I paid $2.99 for at Harbor Freight. Works great and

BlueTrane

I had a problem about a year ago that was very similar. I would start to accelerate from a stop light normally and then the truck would fall flat on its face. I would have to take my foot off the accelerator and try again. It ended up being the aforementioned TPS. Unfortunately, with my model year, I had to replace the entire throttle body because the part wasn't available.

Some might think this is bad advice, but I'd take it to a Firestone if one is near you. They have a flat rate diagnostics fee of $80 and could at least tell you what is exactly wrong. If they can't figure it out, they refund your money. Good luck.

glassfishy

I've really thought about getting it diagnosed, but didn't know if anyone would diagnose without wanting to fix the problem. For example, if I take it in and they diagnose a fuel injector I don't want to pay someone a couple hundred dollars if I can replace the injector myself.

glassfishy

:::::::Head Spinning::::::: I remembered you said go to radio shack and get a resistor. If I go there will they know what I'm talking about or will they look at me like I'm stupid? Is it a test resistor?

I would really like to learn how to use the OHM meter. Thanks 4Crawler.

BlueTrane

Your concerns are pretty legit - I've had pretty good experiences with Firestone. They'll be happy to charge you an arm and a leg to do the repair, but they wont do anything until you approve it. Their diagnostic fee is exactly what it should be - a diagnostic.

MarkieMark

how many miles do you have? could be a clogged cat. i experienced this on my prelude. i got a high flow cat and a magnaflow muffler. had the shop do it for 130. they used 2.25" piping. car ran perfect after.

AaronW

Glassfishy,
I have an '86 4runner with an automatic transmission. I have acceleration problems due to some sort of transmission problem-I think-do you have any solenoids on your transmission? Evidently they keep the transmission from downshifting and then accelerating. Peace, Aaron.

glassfishy

I'm at 187,000. Ya know I never thought exhaust even though I've been smelling the awfullest exhaust smell. It was on my list of things to do when I get my new magnaflow mufflers put on. I've got the Magnaflow sitting shrinkwrapped in a box. Just haven't had time or extra money to get it put on. Wow!! I never ever thought of it being the exhaust. You say yours did the same thing?

Steve

glassfishy

It doesn't feel like a transmission problem. I'm not sure if I have solenoids. How would I tell and how can I check them.

Steve

glassfishy

OK, I hate to bring this thread back up from months ago, but I'm still having problems. It's now started to get worse. I took it to a mechanic and he tested the TPS sensor and said that a wire from underneath it had shorted it out and it needed replacing. So he replaced it and also cleaned my fuel injectors with some sort of machine he had (not sure what it involves). Still is giving me problems

here is what is happening so you don't have to go back and reread entire thread!!

When I start up the car it starts fine and idles great. Then if I drive it or let it just idle once it gets to mid range on temp guage the idle goes down and it runs like crap. If I'm driving it it doesn't sound like it's going to die, but it just won't go. I push the pedal down and the engine doesn't race or anything. It's as if it's not getting gas. The only way I can clear the problem out is to floor it. I do this 2 or 3 times and it stops doing it. Sometimes I hear a popping noise from underneath the truck. Sorta like a muffled backfire, but not loud or anything. I also use the truck for paper delivery so when I do a lot of stop and go driving at slow speeds it tends to get back into it's bad habits of rough idling and not wanting to go, but once I drive it at higher speeds and higher RPMS it does fine. Also, fuel economy of course has gone right down the tubes. Much worse than should even normally be expected.

Here's what I've done:

Replaced Plugs and Wires & Distributor cap (No Effects at all)
Replaced Fuel Filter
Replaced Catalytic Converter
Had TPS Sensor Replaced
Swapped Mass Airflow Sensor from 91 4Runner (no effects at all)
Seafoam Crap
Fuel Injectors cleaned by mechanic
Cleaned Throttle Body

The mechanic said he couldn't pinpoint the problem, but his next guess was to replace the EGR Valve. The problem is I can't keep sinking money into this car. So any ideas that I can try would be greatly appreciated.

The other problem is when i got it back from the mechanic he had unhooked the EGR Valve vacuum hose. I asked him why and he said it idled better without it and that's why he felt like the EGR valve was the culprit. So I've been driving it around unhooked from the EGR Valve. When I hook it back up I don't notice a big difference in idling. And it also causes my Check Engine light to come on.

I don't mind taking it to the dealership, but I know they're going to want $1000 to fix it and the car's only worth $3,000. I recently purchased a newer car so I'd like to fix the problem and sell it.

Any help !!!!!!!

4Crawler

iTrader: (3)

Sounds like the EGR. Why? The EGR starts operating when the engine gets up to temp. Get a Factory Service Manual and test it out yourself. May be hooked up wrong, may be sticking open, etc. It is very easy to test, a simple vacuum gauge and pump and you are set.

glassfishy

OK,

I tested the EGR by doing the suck test posted on another place. I actually bought a Vacuum guage, but we did the suck test instead. When we sucked on the vacuum hose that goes into the EGR valve the idle got worse and just about died. So does this mean the valve in the EGR is working correctly? Stated elsewhere it does. I sprayed throttle body cleaner on all the vacuum lines going into the air intake chamber to see if I had a leak and no change in idle.

I do know that when I hook the vacuum line that goes back into the EGR Valve back up (from where the mechanic that did the work unhooked it) the idle is a bit worse and it drives even worse all the time. It's like I have to give it more gas just to go. And when I unhook it and put a screw to stop up the vacuum line it idles and drives even better.

Steve

4Crawler

iTrader: (3)

Well, that indicates the EGR valve itself is working. But it (or the modulator) may still be hooked up incorrectly. If hooked up wrong, the valve will be opened when it is supposed to be closed, resulting in poor power and idle. Check the vacuum line connections and make sure the valve is only opening at part throttle above about 2000 RPM.