Hey guys,

I've been reading these forums off and on for quite awhile now and finally had to take the plunge and register to see if maybe you guys can help me out.

About me and ford - I've only owned 2 fords in my 36 years and both have had problems that made me give the first away to a junk yard because I couldnt find the problem, and the second is about to that point. So I'm going to try to salvage my relationship with the Ford by hopefully getting help from you guys on diagnosing the issue.

Okay, enough with the rant, lets get down to business.

2000
Ranger
XLT
2 wheel drive
2.5 L

I bought this truck about 3 months ago. When I test drove it, it started fairly easy (considering it hadn't been started in about a month), idled nice, and had the power of a typical 4 cylinder. No more than a week after the purchase the problems began.

I went to start it about a week after buying and it just rolled over. I tried it a few times and couldnt get it to start. Went inside cussing the guy who I bought it from (my cousin) and decided I would start with the least expensive first, the fuel filter. I went back outside and tried it again and it fired up but wouldnt idle without giving it fuel, and even with giving it fuel, it was rough in the low end. So I replaced the fuel filter, tried it again and nothing changed, still ran rough and wouldnt idle. I pulled the MAFS and cleaned, reinstalled and nothing changed. Replaced the IAC Valve and nothing changed. Pulled a couple plugs to see how they looked and they looked good, (didn't pull them all though). Checked for a vacuum leak and one of the tiny hoses on the right side had a hole rubbed in it. I fixed that and still nothing changed. Also sprayed brake cleaner around the throttle body and intake and there was no leak. I bypassed the front 02 sensor and nothing changed. Pulled the PCV valve and cleaned, the marble rattling was good, put it back in and no change.

It doesnt matter if the weather is warm or cold. And sometimes it's worse than others. Sometimes it will idle pretty smooth for awhile, then idle up and down. When it idles up it sounds okay, when it idles down it gets real rough and eventually dies.

I can drive it and it does alright until I hit a light, then the only way to keep it running is a foot on each peddle.

I ran the codes awhile back, but I cant remember what they were. I remember one saying something about running rich on bank one.?

Soooo, any thoughts? I have no idea what else to try.


PS- The guy I bought it from said he replace the fuel pump about a year before I bought it. I tried to check the fuel pressure but the fittings from the "rent-a-tool" werent the right ones.

Thanks in advance.

We had a similar sounding problem: rough hunting idle with codes P1130 (Lack of HO2S-11 Switch, Fuel Trim at Limit) and, as I recall, P0170 (lean, Bank 1).

The real problem was the intake manifold gasket. Replaced it tonight and everything is fine. No codes, no rough idle, great power.

Along the way to this revelation, I say that because the problem is common on the 4.0L but I had not read a word about it on the 2.5L, we did the following:

1) Tested for vacuum leaks by spraying brake cleaner along hoses and fittings. As a result we replaced a number of older hoses including the PCV hose, the PCV and its grommet, and the injector O-rings.
2) Cleaned the MAF with MAF specific cleaner, 2nd time anyway.
3) Replaced the IACV.
4) Tested the EGR Valve and EVS (EGR Vacuum Solenoid).
a) Repeated the test on the EGR with it off the car. When we held a vacuum on it and blew through the opening the vacuum leaked down so this time we replaced the EGR valve.
b) Cleaned the EVS. Ours appears to be the "enhanced" EVS, not the Duralast EVS58. It has a service port.
5) Cleaned the throttle body, etc.
6) Replaced the O2 sensor.
7) Replaced the fuel filter.
8) Tested the fuel pressure at the fuel rail. (Should be at or just over 60 psi. Ours was.)

As useful as the codes seem in theory, it is still a matter of finding the culprit. I have read of others with the same codes who needed a valve job, or a fuel pump, or just an oxygen sensor, or just a MAF, or who just couldn't find the problem. We were patient and thorough. We were motivated to move along the diagnostic path selecting the cheapest possible solutions first. I really appreciate the support of the Forum and hope when others find solutions to their problems they, too, will post them.