replaced the fuel filter and car is still bucking
 

Ok guys...a few months ago I had some coolant issues and the car got hot blowing steam and coolant everywhere. Anyhow it took me a few times to figure out exactly the issue and the last time I took it around the block with no coolant (I figured it out and put coolant thru the block) it hesitated and bucked really badly.

How could me running the car with no coolant affect the bucking? Anyhow I put coolant in it and fixed the cooling issue but now for the last few months I get bucking and hesitation that seems intermittent and doesnt usually last more than a few minutes. I thought I had a dirty filter and replaced it and I havent replaced the spark plugs in at least two years though I have pulled them and cleaned them a few times, even recently. So is there anyway whatsoever that overheating my car could cause any bucking or hesitation? Any ideas?

And you last checked/adjusted your TPS... when?

-=Russ=-

I havent, and someone told me that the sprayed coolant could have gotten in their so i sprayed soem carb cleaner and it still does it...i guess I have to check it tomorow then...but would my TPS make the car seem like it is missing fuel/spark?

aight i have done it once with a buddy and searched the archive and know it is a simple newb question but EXACTLY how do i check the TPS...i know i stick something ont e thing and then a ground and do the screw until i have a 1 ohm or something or another but dont remember the specifics...could someone fill me in?

There are different ways of checking, but my personal favorite is this. Warm up the car, shut off (but leave ignition 'on', just no engine running).
Put '+' of DIGITAL volt meter in the TPS plug, the green wire with stripe. The other negative side of meter to battery (-).
Adjust screw to get as close as possible to 1 volt. Work throttle plunger several times, re-adjust as needed.

Worked for me every time.

cool beans...thanx man

Hey, could you show a pic of what the adjuster is on the TPS? I think mine might need it.

the adjuster is that screw top that needs the flathead with the spring around....that is the adjuster anyhow..the TPS itself i beleive is the bell thing with the wires going into it....

i had an 87 t2 that had a bad bucking problem that seemed to get worse the longer i drove it. ended up being the fuel pump. it wasn't putting out enough fuel pressure under load the best i can figure.

yeah this seems to happen after I drive it a bit....when I first start her up and drive her around I have no issues whatsoever but after driving around for 20-30 minutes it starts to do it, especially if I park it and turn it off and get back in it again after a small while. Would the fuel pump go out little by little and intermittently? And this doest seem to happen under any particular load.

OMG you have the exact, I mean exact same problem I have right now, if someone can figure this out I will owe my life to you, i just replaced my fuel pump with an FD fuel pump and still have the same problem, It works fine when cold but as soon as the engine ully warms up after about 15-20 mins of driving it bucks and like looses fuel or spark. I was told it could be my temp sensors, anyone else vouch for that? Ohh sorry fo hijacking ur thread, im just in desporate need and you described ur thread alot better than my other 3, lol

hey man we are in the same boat and I want to see what the deal is. I still have yet to check my TPS and I know this most likely has to have something to do with my car overheating those few times, whether directly or indirectly. Also not to mention the overheating happenned at the end of a 3300 mile trip of which I drove 2300 miles in 40 hours straight of driving, so it could have been something related to THAT and not the overheating which happenned at the same time.

wait you mentioned something of a temp sensor. Overheating my car could have affected that sensor but what does that sensor have to do with fuel and spark? This could be the link but I still dont understand the means of how. If anyone could explain how the temp sensor could be related to this then that would be great.

Well the temp sensor has alot to do with fuel. The temp sensors have a tendency to get stuck open and read at a high temp all the time. Last night i took off my intercooler and took off my temp sensor to check the resitance. It should read(when completely cooled, my car was) any where from anywhere around 41.5 ohms. Mine was reading 4 ohms , meaning the resistance was lower and it was not reading the correct temp of incoming air, if its colder it will tell the computer toput more fuel, colder air means means denser air meaning more fuel, and if its stuck open it will tell the computer that the incoming air is alot hotter than the actual air, meaning hotter air = less dense = less fuel needed. So if the temp sensors are messes up it will be telling the fuel computer to put the wrong air/fuel mix ratio. If its only happening to ours cars when they are warmed up then thats telling you that the computer could be thinking its getting intake temps of sky rocketing temps there fore starving us of fuel, I hope this makes sense, its alot easier to say then it is to type.

ok sounds good, BUT would my temp sensor go bad from the car overheating or spewing coolant over the engine bay?

It could, Not sure

Yeah I' ve had the same problem for over ayear came to the conclusion that it could the water thermo sensor that is locate it behind the water pump next to the alternator, I already have the spare sensor but I haven't had the time to change it, i hope that on the next weekend have some free time to replace it and check the results.

Enriquez

thats what I heard and maybe heating it up to the boiling point a few times was enought to fry it....ill give it a shot...

also....if this is the thing then wouldnt my temp gauge be skyrocketing too if the sensor was reading high temps?