Close
Car Questions
RepairPal is your advocate for car care advice and guidance

86 ranger 2.3 bucks if press gas more than 1/4 way, idles perfect, is tuned up

(1990 Ford Ranger)
in Berea, KY on March 03, 2017
Truck is 86 ranger 2.3. Has full tune up on the vehicle and idles perfectly, but while driving if I press the gas too far down (over 1/4 pedal) or if rpms get above 3000 it jumps bucks spits and loses almost all forward momentum. And has a horrible time trying to climb a hill. This is every time i drive it and its a struggle to get it above 50 mph. Also which type of TPS would this truck need? Also not sure if it is original engine or not but is the 4 plug version fuel injected. Also has all new fuel system including but not limited to tank filter pump sending unit and lines. Thanks in advance
Displaying 1 answers & 5 comments
Popular Answer
on March 03, 2017
Hello,
This vehicle may have a fuel delivery issue, or a vacuum leak. There are several other possibilities, however, these two seem the most likely.
Smoke test for vacuum leaks, and pressure test the fuel system. Also, there may be an issue with the exhaust, specifically the catalytic converter.
on March 04, 2017
I've already had a pressure test of fuel system and it shows to be good... haven't done a smoke test as of yet but will try that as well... did hook up to a computer and the only issue it shows is the TPS also I unhooked the TPS yesterday and it ran BETTER with it unhooked that with it connected
on March 05, 2017
You can test the TPS by checking that the signal to the ECU increases in voltage as the throttle body is opened. If you find dead spots, even at idle, the sensor will need to be replaced. Also, you may find that the connector is dirty, or that there is no voltage leaving the sensor. Anything besides smooth, gradual increase in voltage means replace. Also, check the idle air control port inside the throttle body.
I really am starting to think there is a vacuum leak, and the engine runs better with the MAF and TPS disconnected because it is using the O2 sensors exclusively to balance the engine fuel/air mixture. Normally the A/F ratio is calculated by the computer comparing the various sensors on the engine, fuel system, and exhaust system, and equating those values to tables to establish a constantly variable ratio, according to engine conditions.
When there is a vacuum leak, the engine sensors will send incorrect air measurements, and the O2 sensors will send proper measurements.
My money is on vacuum leaks. Spray water all over the engine, one spot at a time, use a spray bottle to control the amount sprayed, and you should hear the engine change its tone when it sucks water through the vacuum leak. Or smoke test it.
on March 13, 2017
OK so I sprayed the engine down with water... no effect at all... and as far as fuel delivery... I know for a fact that the fuel pressure is there, (bought a gauge just to test it and looked up specs), so I know for sure it has to be Contained somewhere within the engine its self not a line/filter/pump and so on... one person told me to check the fuel injection regulator although not sure how to test it aside from dis-connecting it from the vaccum line which doesn't change anything going down the road but without it connected it won't start back after being shut off... any ideas? Also I put on new plugs wires cap and button and has a nearly new coil... idk what to do with this thing, all I do know is I gotta get it right soon or it'll be time for a motor swap... which with all the new parts on this motor will be a pain considering I'm not letting new parts go to waste... please help oh and ps. I checked the exhaust... cat converter is no longer there... replaced with strait pipe so cat is definitely not the issue
on March 13, 2017
Do you have a timing light? There is a good possibility that your vacuum leak is internal, if it exists. I really feel like it does. Test that by pinching off the vacuum lines to vacuum operated components, and see if your engine runs differently. The vacuum booster is a big culprit here, and the very obvious thing that I overlooked before is the distributor vacuum advance canister. If the vacuum advance and/or mechanical advance are not working, the engine will not be able to achieve higher RPM with any load. In fact, that replicates your position so well, I'd say try it first.
When the vacuum advance canister is disconnected, or the vacuum line is pinched closed, the engine should have a harder time reaching higher RPM while driving. If it runs the same, the vacuum advance canister is likely leaking internally.
This also applies to the vacuum booster, but the results from the booster may vary depending on how small the leak is, if it exists.
Straight pipes don't clog, so that's a no-brainer, but the fuel injection regulator being disconnected with the vacuum line plugged should cause a change in performance, especially at higher RPM, so since there was no change, it needs a little more testing.
A vacuum pump will tell you in a very accurate manner whether or not vacuum components with diaphragms are leaking. Connect the pump, suck the air out of vacuum components, and see if the vacuum drops on its own.
If you don't have a vacuum tool, there are some really cheap options everywhere. I would not expect more than $20-25 for something with a gauge on top.
That's the next step. Did you test the TPS to see if the signal voltage rises as the gas pedal is pressed?
on April 25, 2017
OK so... since the last conversation I have tested like crazy for any type of vaccum leak to no avail, replaced the tps ran a fuel cleaning agent and tested all vaccum components with a gauge, all showed well so I had a compression test done... losing dramatic amounts of power on 2 cylinders... so I think I've found my issue... not really sure if this engine is worth putting rings and what not in, so I'm considering pulling a motor swap and being done with it. If you have any other ideas before I go to that extreme of measures please feel free to throw them at me, I'm willing to consider almost anything to fix my truck at this point
Get a repair estimate
RepairPal estimates are guaranteed at over 2,000 quality certified locations nationwide.
Or interested in getting a repair? Find a Shop

Similar Questions

View answers to similar questions from RepairPal's community of auto experts and enthusiasts.
One of the vacuum lines has come unplugged. still attached to the vacuum ball (reservoir?). its the one on top (i kno...
No reverse,all other gears work
Didn't find what you were looking for?