Hello all,

Recently bought a 1990 Ranger, 4cyl, that likes to bog down a lot when I try to take off from a dead stop. It also feels like it has no power on the highway.

What I've done so far:
Spark Plugs/Wires
Timing Belt
Cleaned IAC
Cleaned EGR Valve/Port in intake
Cleaned MAF

The truck always feels like I'm putting it in a gear higher than the speed I'm going. You know what a stick does when you put it in second and try to take off from a light? That's what it's doing in first. My idle also seems laggy when I put the truck in neutral to come to a stop. It seems to take far too long for it to come back down to idle speed.

I've had some suggestions on what to do. They are:

(Replace/change)
Air Charge Sensor
Air Cleaner Temperature Sensor
Coolant Temperature Sensor
Fuel Pump
Fuel Pressure Regulator

I'm not sure where the best place to start would be. I'm not even sure I'm explaining the problem well enough to be of any help.

Thanks in advance for any help. Please don't hesitate to ask for any more information you might need.

P.S. Little side note: I looked up the Air Cleaner Temperature Sensor online... and I have never seen anything that looks remotely like what was pictured on my truck. So, I might need some detailed instructions/pictures as to where these things are located.

 

Welcome to FTE.

You may have more than one problem.

Do you have a CEL lit????
If so, there are trouble codes stored in the computer that could offer up some trouble shooting clues.

Most autoparts stores will do a no cost computer scan if the CEL is on, but noting the vintage of your vehicle, call ahead & check that their scantool will hook up to the underhood connector.
Advance Auto in my area can scan OBD-1 vehicles, with their Actron CP9145 scantool, but maybe not all stores use a scantool that'll hook up to OBD-1 vehicles.

If you can't find someone to scan it, you can do it yourself using the proceedure outlined in the "Tech Info" thread atop this forum. Lots of other good wrench turning info there too.
Post All of the code Numbers found.

If you don't have a CEL lit, then the sensors you suspect are likely ok, so maybe do some light diagnostic trouble shooting, like a fuel pressure & fuel flow/volume vs time test.

If it's low, maybe suspect a clogged fuel filter, if it hasn't been changed lately.

Or as has been suggested, maybe the fuel pressure regulator on the fuel rail is bad, or acting out.
So pull it's vacuum line & see if it's wet inside with fuel. If so it's diaphragm is bad, replace it.

If all that checks out, maybe suspect a weak fuel pump, or clogged up pre filter sock on the pump thats limiting flow/volume, or maybe a voltage drop to one of the pumps from faulty or corroded wiring.

Be sure to check the air filter & make sure the air box & air tube to the throttle body is properly buttoned up.

When you cleaned the MAF sensor, was it cool & did you use a plastic safe, non residual cleaner, like CRC MAF Sensor spray cleaner???? Any residue on the MAF sensors heated electrodes will bake on & corrupt it's PID output to the computer, about true air flow into the engine. So it needs to be squeeky clean!!!!

Have you tested the throttle position sensor, to make sure it's resistance is in spec & changes smoothly across it's full sweep, as the throttle is opened????

Are you certain you got the timing marks aligned properly, when you replaced the timing belt????

Is the engine spark timing ok????

You are wise to suspect the IAC on idle problems & cleaning it may not solve any idle problems it may be causing. Cleaning mine didn't last, so I suppose thats whay Ford recommends we replace an acting out IAC, but cleaning mine was a good trouble shooting step for me.

A whole bunch of thoughts to ponder, keep us posted on your trouble shoot.

 

There's no CEL right now. It's also kind of hard to find a parts store willing to let you use a tool like that.

How do you do the "fuel flow/volume vs. time test?

Sorry, forgot to mention that in the OP. I had the fuel filter replaced when I did the initial maintainence when I bought the truck.

Yes, I did it in the shade and used the CRC cleaner.

No, I haven't done this. Don't think I have the right tools to do so either.

I have no idea. I had a garage do that part for me as I've never done it myself before. I asked the guy at the garage if it needed to be "re-timed" when he changed the belt and he said "No, it doesn't have a distributor. I won't need to do anything like that." Maybe I shouldn't have listened to him?


Thanks for all the ideas. I'm going to check the regulator on my lunch break today. I was seriously buying the fuel pump assembly and putting it in this weekend.

 

Most autoparts stores have a "Loan-A-Tool" program, that'll let you check out what you need, for a refundable deposit. Most test tools will have use instructions with them & a look in our Tech Info thread will have a lot of how-too info on the tests I spoke of & the forum can probably talk you through anyhing your having problems with.

If you want to learn how to turn your own wrenches on your ride, consider investing in a good service repair manual, or CD, if you think you want or need more detail.

Your local library might be a good source to check out printed manuals, to see which ones format most closely meet your needs & likes.

If the gararge algned the cam & crank marks correctly when they changed the timing belt, then the valve timing & spark are likely ok, but an inductive type timing light would quickly, easily & safely confirm that the spark timing is ok.

Don't throw parts at your problem, take the time to trouble shoot, test & confirm a part is bad, before replacing it & thats where a repair manual, or CD & this forum can help guide you.

So from the loan a tool program, come by an inductive timing light to check spark timing, a multimeter to test the TPS resistance, a fuel pressure test gauge for fuel pressure & flow rate & maybe a compression tester & have at some basic trouble shooting & let us know what you find.

 

Just thought I'd let you know that a lot of think links in the Technical Information thread no longer work. They direct to a page for "AOL Hometown" being shut down.

Kinda sucks because most of those are ones I would need to look at.

I've also contacted some of the parts stores around here and they don't have code scanners to loan out, or timing lights/pressure testers. They mainly just have pullers and things of that sort. Trying to get my hands on the right tools before this weekend. I'll post back then.