cant go highway speeds

[jared]

I have a 92 ranger with 2.9 and auto trans. The truck idles great and runs strong untill i try to drive on the highway. The truck tops out at about 50 at 3k rpms. When I drive it never gets above 3k, in park or neutral it will rap out so I am thinking it must be something in the tranny almost like it is shifting to early. Any suggestions?

 

[RyanL]

I have a 92 ranger with 2.9 and auto trans. The truck idles great and runs strong untill i try to drive on the highway. The truck tops out at about 50 at 3k rpms. When I drive it never gets above 3k, in park or neutral it will rap out so I am thinking it must be something in the tranny almost like it is shifting to early. Any suggestions?

It sounds to me like you have some sort of engine trouble it it wont rev above 3K. Pull your codes to see what you get.

 

[jared]

It sounds to me like you have some sort of engine trouble it it wont rev above 3K. Pull your codes to see what you get.

ok will do, the thing that make me think it might be tranny is that when it is in park or neutral it will rev past 3k its only when it is in drive that it bogs down its almost like if you shift a manual too soon.

 

[crustacean]

Not to be boring, but how about the fuel filter?

 

[jared]

I have changed the fuel filter, plugs, wires, airfilter, and cleaned the throttle body. is there a way to change the shift settings on an a4ld?

 

[RyanL]

ok will do, the thing that make me think it might be tranny is that when it is in park or neutral it will rev past 3k its only when it is in drive that it bogs down its almost like if you shift a manual too soon.

When the vehicle is in park or neutral there is no load on the motor so that wouldn't be a good test. I understand what you're saying about it shifting early or whatever, but does it rev past 3K in top gear? If it doesn't then it sounds like an engine problem.

 

[TimR]

When the vehicle is in park or neutral there is no load on the motor so that wouldn't be a good test. I understand what you're saying about it shifting early or whatever, but does it rev past 3K in top gear? If it doesn't then it sounds like an engine problem.

How about putting it on a lift, or 4 jack stands, and running it through the gears? note the shift points and tach readings...

 

[jared]

When the vehicle is in park or neutral there is no load on the motor so that wouldn't be a good test. I understand what you're saying about it shifting early or whatever, but does it rev past 3K in top gear? If it doesn't then it sounds like an engine problem.

I never thought of that. Even in top gear it stays right around 3k. I had to drive it about 45 miles on the highway and had it floored the entire time and could only go around 50 (speed limit is 70) occasionally I had to let off the gas because the truck would start backfiring. I know the 2.9 is not a powerhouse bit it should definitely be able to get this truck over 50 mph and its 0-50 is about 30 seconds.

Since I have already replaced air/fuel filters, plugs and wires as well as cleaning the throttle body what would you recommend? I will try to get the exact shift point today.

 

[Dave90ranger]

ok get a fuel pressure tester and see wat fuel pressure does when it sits at 3k and wont go faster be cause what your explaining was sort of what i had happening and my fuel pressure would drop like a rock when it wouldnt accelerate and found out my fuel pump was faulty. as soon as i changed it out it stopped and fuel mileage went up and had lots better performance.

go to harbor freight and get a tester i think it was like $30 for it and it hooked right up. only thing i had to do to see it was have the hood open and put the gauge by the wiper then close the hood(no it wont effect wat the gauge says with it like that)

 

[RyanL]

ok get a fuel pressure tester and see wat fuel pressure does when it sits at 3k and wont go faster be cause what your explaining was sort of what i had happening and my fuel pressure would drop like a rock when it wouldnt accelerate and found out my fuel pump was faulty. as soon as i changed it out it stopped and fuel mileage went up and had lots better performance.

go to harbor freight and get a tester i think it was like $30 for it and it hooked right up. only thing i had to do to see it was have the hood open and put the gauge by the wiper then close the hood(no it wont effect wat the gauge says with it like that)

I would nominate fuel issue too, but he mentioned something about backfiring. That right there tells me it's probably an ignition issue, maybe a bad TFI. When my TFI went up recently, it seemed to mess with my timing and robbed power (not to the extent of the OP, but it still was an issue). There's so many different things that could be going on. First things first though, you need to pull your codes Jarad to see if you have anything at all. If you don't have a an OBD reader, you can use a test light or even a little jumper wire and count the check engine light flashes. If nothing turns up then you could have a failing fuel pump or maybe even a bad regulator (to test the regulator pull the vacuum line off of the back of it while it's running to see if any fuel drips from it). The best deal that I could find on a fuel pressure tester was at a Salvo Auto Parts for $40 with just 2 different fuel rail fittings. Everywhere else I went wanted well over a hundred for theirs because they had kits with a million different fittings in them which came in a suitcase. Pull your codes first before you jump to any conclusions and even after you do that check back here to see what they mean exactly (sometimes codes can be misleading).

 

[Sasquatch_Ryda]

Plugged exhaust perhaps.

 

[Dave90ranger]

oh forgot to add when my truck had its issue it would only go so fast and it sounded like it backfired too but it wasn't really a backfire at all.

oh and codes being misleading is very true since i had about four codes at once then i cleared them(with the fuel pump issue still happening) and then re ran codes and had something different. and i did this about three or so times more and had different codes everytime so i got the fuel pressure tester and that concluded the issues. have no codes now and have been running it weekly to see if any pop up which i have none. so if you have the same sort of issue like i did then checking codes and fixing them will waste time(not insulting anyones intelligence just want to state a point here). but yea still check codes first and see whats there. if you get codes that deal with stuff you know you have no issues for then it may be like what i had. (basically i think having the fuel pump issue confused the computer so it spit out random crap that had no issues)

 

[RyanL]

Plugged exhaust perhaps.

That's very possible too. That happened to my wife's Jetta not too long ago. I chunk of the catalytic converter broke off and basically blocked the exhaust. I was driving it at the time and it was so bad I almost pulled over to call for a tow, but managed to limp home (it wouldn't go over 40MPH). The exhaust was rattling beforehand, but I swore it was a heat shield or something rattling. Getting to the bottom of that problem was fun. I decided to check the exhaust as a last ditch effort. Point is, it really could be almost anything causing the issue.

 

[RyanL]

oh forgot to add when my truck had its issue it would only go so fast and it sounded like it backfired too but it wasn't really a backfire at all.

oh and codes being misleading is very true since i had about four codes at once then i cleared them(with the fuel pump issue still happening) and then re ran codes and had something different. and i did this about three or so times more and had different codes every time so i got the fuel pressure tester and that concluded the issues. have no codes now and have been running it weekly to see if any pop up which i have none. so if you have the same sort of issue like i did then checking codes and fixing them will waste time(not insulting anyones intelligence just want to state a point here). but yea still check codes first and see whats there. if you get codes that deal with stuff you know you have no issues for then it may be like what i had. (basically i think having the fuel pump issue confused the computer so it spit out random crap that had no issues)

If it doesn't sound something like a firecracker then it's probably not a backfire. The reason why I said that the codes can be misleading is because you have to know how to interpret them while checking for other obvious problems. An example would be something like a lean run code, but the exhaust looks and smells rich of fuel. You know that it's not running lean so the best suspect would be the oxygen sensor. BTW, in your scenario you might get a few codes from fuel starvation such as a lean running code and possible misfire codes (a motor will miss if the A/F is off badly). It shouldn't just spit out "random" codes. They should all be related in one way or another.

 

[cavedweller]

I second a hard look at the exhaust ...Letting her cool down,give her the rubber hammer test,(hit both cat portions with rubber hammer),...if you get rattling ,there is your problem ...If not look at different sections of your exhaust,like some one else indicated,it sounds like an obstructed exhaust.