88 Ranger xlt 2.9 HELP

[Monchi88]

Hey guys I'm new here and I finally joined to get some extended help after I been reading up on the forums.

So I have a 88 Ford Ranger xlt 2.9 2wd automatic. Picked her up for $400 and she ran great when I brought her home. She sat for a month in my driveway while I was touching her up before I get it registered. One day I went to turn it on and itll only crank but not turn on. I noticed the fuel pumps wouldn't prime so that was my 1st move. Changed both fuel pumps and filters and new gas because the old gas was a dark red color and had something looking like mold in it.. still didn't turn on and pumps wouldn't prime. I went to the junkyard to get 2 ECU's just incase one didn't work. Plugged one up that i git from an 89 ranger 2.9 auto and it took a few tries to turn on but when it did it idled perfectly and it'll stay there idling forever. But once I press the gas just a little bit it dies out and shuts off. If I was to floor it it usually wouldn't pass 2500 rpm but occasionally it will.
I now got a check engine light and I got the code 26 which is the map sensor. I put a new map sensor and didn't make a difference. Today I checked the fuel pressure at the rails and it's spot on, 31 psi at idle and 41 psi at WOT (even though it doesn't pass 2500 rpm at wot).

I'm stumped now and only thing I can think of is the injectors or I got a bad computer. What do yall ranger gurus think?

Thanks in advance

 

[Spott]

I think you need to test things before throwing parts at it, because that often just complicates the issue without identifying the cause of the problem.

If your fuel pumps don't run, check your inertia switch, fuel pump relay, grounding signal for the FPR, and then EEC power relay first.

I wouldn't use an '89 EEC in an '88 truck; they made a couple of electrical changes along with the body changes, and when the '89 EEC sees those are missing it might generate error codes and run poorly.

 

[RonD]

Code 22 MAP (vacuum) or BARO signal out of range - MAP
Code 26 Mass Air Flow (MAF) or Vane Air Flow (VAF) out of range - MAF VAF(you don't have this)

'88 will have a TFI ignition module on the side of the distributor.

It will also have a SPOUT(spark out) "jumper" on a wire coming from computer and going to TFI module, the SPOUT jumper will be closer to the TFI module on top of lower intake.

Google: SPOUT connector
To see what it looks like
Or here: http://s527.photobucket.com/user/gertsdsbs/media/spout002.jpg.html

That gray piece pulls out of the white connector, by removing this the computer can not control spark advance, so on yours it may be removed.
If it is remove then there will be no spark advance when raising RPMs.
If it is missing put a jumper wire in there until you get one at the wrecker.


Other issue could be TPS(throttle position sensor), it is on the upper intake connected to throttle plate shaft.
It tells computer if throttle is open and by how much.
Inside it is the same as a volume control or light dimmer, a variable resistor.
Computer sends it 5volts on the top wire
TPS sends back 1volt(.7-.9v) on center wire when throttle is closed
Then center wire voltage gradually increases as you open the throttle
At WOT center wire will have above 4.5volts

 

[Monchi88]

Yeah before anything i pressed the inertia switch, nothing happened. But yeah I didn't think that the ecu would of made a difference but I'll change it out to an 88 ecu. I'm use to Hondas where any honda ecu would work on them. Thanks though I'll let yall know what's happens when I change it out.

 

[Monchi88]

Thanks Ron. I'll look into that as well.

 

[Spott]

I would try to put the original EEC back in, and then determine why the fuel pumps aren't running. The EEC is quite a robust piece of electronics; it's not very likely that it just spontaneously failed while sitting dormant for a month.

Just because the inertia switch wasn't the problem, doesn't mean that you've proven that the fuel pumps were bad. You skipped testing the relays, connectors, power and signals that control the pumps. Replacing the pumps doesn't solve the problem if you have an intermittent relay or a loose connector.

With all the money you're throwing at parts, you should also spend $15 on a basic multi-tester and learn to make simple voltage and resistance measurements. It can save you hundreds by preventing the replacement of parts that are still good.