Surging/Thrusting Problem Under Acceleration

You can't find a broken injector without getting it tested plus no..it's cheap to get done.

And lol..I've seen the MAF get call AFM and MAP in the last three pages while they all merit e same result..they are different...maybe that's just me being picky tho..

 

Yeah does the engine have a MAP. That's a question

Yes or no

 

What I'm suggesting is that pulling off the SC and making the vehicle untestable and 100% out of commission for the moment wasn't the smartest thing to do.

Aside from having an arsenal of computer scanners for OBDII for every car I can think of which only further helps my diagnosis out. I can also find a jacked up injector by pulling the plugs as it runs but hey, it's not my truck, and everyone has a different way of doing things. If he wants to go that route, by all means, more power to him.

Good to know it's cheap to get them tested. I've never had to do that before so that's why I ask.

 

No

We have MAF sensors on 1st gens

Visual inspection will help a bit. But your not going to really full be able to see 50-70cc difference. Which since its not running horribly..could be how much one is off.


Taking the sc off means the sc isn't causing the problem..important to know.

Truck is drivable as he put the stock brake back on

 

a lot of cars have both genius. you can facepalm all you want.

 

Lol what???? No they don't..not Toyota anyways. Especially not 1st gen tacomas..

 

who gives a fuck. it's a question. look at all gen3 and gen iv gm v8s.

you don't have to be a prick about it.

 

Well excuse me..was pretty sure we were on a Toyota forum..and in The 1st gen section..

I wasn't being a dick. I'm sorry a little facepalm emoticon pissed you off..but it's the Internet..get over it.



Okay..anyways. Jason what have you got?? Anything new

 

The stock intake manifold you mean?

Typically if I see that kind of difference I would see it in the fuel pressure indication on my gauge I hooked up, which would lead me to those but my thing is that he shouldn't had let it get that far out of hand and 17 umpteen bajillion sensor replacements later. It happens from time to time but when it is your own personal vehicle the diagnose process needs to be a little more methodical and direct. Anyways, I'm sort of digressing here, lol. I will be observing in the background, don't mind me.

If I am not wrong, I believe the MAP is integrated into the MAF on the Toyota 1st gens. Someone correct me If I am.

 

check compression on all cylinders. A low cyl can cause a misfire symptom at part throttle.

 

No.

A map sensor take pressure reading off an intake manifold. Mf sensor read the amount of air moving pass a filament by sensing how much it moves.

Map sensor can't be as far forward as jr macs are as they are always located right behind the air filter.

We do not have map sensors.

And yea sorry intake manifold lol damn iPad.

Yes a pressure and a/f wide band o2 would help I agree.

 

I didn't miss it haha i new it was together..

I have an AEM wide band I haven't used...also have an LCII which is my dads(hasnt used it in forever)I think just plugs into your OBDII port and with give you the A/F. I could ship it to you if you want to test it..but now that I think about it. Think you still have t get another bung welded on..

In short..nothing new tho..hmmmm..

Odd shit going on..




Guy talking about graphing meter is talking abou making sure the TPS isn't skipping..seeing as how 2nd gens have an electronic TB. Since ours our cable..not important.

 

Hmmm well that could be something to look at. Idk where you'll get a graphing meter.

Hell maybe the throttle cable is just sticky

 

oh btw.............<3

 

Thanks for telling me, but I know what a MAP sensor does.. I just thought for some reason they just integrated it into the MAF on 1st gens.

Oh shit, what a mess.. I thought nevada did it or there were stations closeby that did it. Damn I guess I am wrong. And you are doing good, take care of the tuneup items first.

Spark- Very easy to test, while the car is off take off a wire and hook it up to a screwdriver (preferably a insulated one with a rubber grip) and take it over to a good grounding location. Hold it about one inch from said ground and have your helper jump in and crank the car a couple times (Not starting it) if you have a very strong spark it will indicate itself by being able to jump that air gap. That is just about the best way to measure quickly and efficiently without any fancy schmancy tools. I don't remember how the 1st gens are but if they have a non coil over plug system which I know they don't they have a coil, you might want to investigate that to see if it is giving up when the issue is happening as well. If they have coil packs then the issue is a little harder to track down.

Fuel- The gauge I was talking about was a fuel pressure gauge (which you might not have but I was using an imaginary one). You need to find out what proper spec is on the fuel for the truck and from there you need to check it out (make sure the PSI is within spec while the issue is happening) If you are experiencing drops in pressure as the problem happens you need trace several fuel components:

-Fuel pressure regulator- Is it leaking?
-Fuel pump- Is it losing pressure as you drive?
-Fuel Injectors- Could they be partially clogged or just crapping out?
-Fuel filter- Is it causing fuel starvation during said issues? If so you are running lean and it would be a good idea to pull it out and check it. One thing I used to do was pull it off and I know this sounds weird but blow on it and see how well it is letting air through, just make sure you clean the tip you are going to be blowing on because fuel tastes like shit.

Lastly- A graphing scope is a scope which displays voltage in its digital form in a graphing style. It displays voltage as well as a graph over time (typically they can be set to milliseconds or seconds) of the electronic component you are testing. TPS sensors in this case have a .50 to 5 volt range I believe, the particular wire you will be checking is the reference voltage wire. Around .50 when the throttle is closed and around 5 volts when the throttle is wide open. As long as you are within those specs great, now if there is a dead spot you will notice that there will be a break within the graph. It's very easy to find. You may be able to get away with a digital voltmeter but that's if worse comes to worse. The biggest issue is that this scope I speak of is typically available within a scan tool. A dedicated one too, not one of those pocket style ones. If you have friends with one of these I suggest you buy them a coffee so they can let you borrow it.

I'm glad to know the rig is at least up and running. Happy diagnosing! If you have any other questions feel more then free to ask me and I'd be more then happy to do what I can from here to help you.

If the throttle cable is sticky you could typically feel it the moment you try and hit the gas, not only that, if it was sticking while he was driving he would have trouble stopping the truck. This truck is older so one thing he could also try is take the cable itself and spraying some silicone spray inside of it and working the cable to get it all in there. I doubt this is his problem but if it is, fantastic!

 

How are the head grounds? Is there one ground in front of each head and one in back? Engine block ground good? Body grounded to frame?

a fuel pressure gauge is just a psi gauge, some fittings and a hose. You should be able to make one for around 20-30 bucks. South lake has a decent ace hardware that may have everything.

http://minimopar.knizefamily.net/quickfpg.html

My 98 2rz was having similar problems after 2 vavles shrunk and it lost compression in one cylinder. Have you checked compression?

My buddy had a similar issue on his 99 tacoma 3.4 while we were heading back from bording in tahoe, he switched out the plugs AND wires and it was fixed, but his check engine light was on and It seems you've covered this already...but i thought i'd just mention it.

 

nice, i just edited my post with a diy fp test kit but nobody can pass up free.