Running issues? HELP ME!!!!!!!!

[Ranger_man]

Alright....I need serious help. here goes.

I have a 87 Ranger with a 2.3L. The engine runs to 2700, then drops to about 2500, then revs back up. This does this no matter if its sitting still,or at WOT. I have the followng items replaced/tested:

fuel lift pump
EGR valve
fuel pressure regulator
Fuel pressure (40 PSI)
spark plugs
timing
timing modulator

The engine has about 10K-12K on it. The engine does smell to be burning rich.

 

[lil_dq]

cams maybe??? I know with a high performance cam, the ecu will "hunt" for an idle spot but idk about a stock cam, if it will do it if the ecu is screwed.

 

[blacksnapon]

Do the basics first: check for vacuum leaks, vacuum can cause a lot of issues:egr, fuel pressure fluctuations, idle speed motor problems.

 

[d-kuzmen]

Do the basics first: check for vacuum leaks, vacuum can cause a lot of issues:egr, fuel pressure fluctuations, idle speed motor problems.

Also checl compression have seen some burnt valves on thos engines.

 

[Ranger_man]

Check vaccuum many times...haven't check compression. I'll give that a look. Anything else?

 

[Fellro]

How about TPS? Since it hits at a certain rpm, seems it may be related to that fact somehow... Another thing to consider is the cat maybe plugging.

 

[Ranger_man]

I've always been curious about the TPS. How would I check/adjust it?

I've also had the cat checked.

 

[Fellro]

Typically, there really is no adjustment to the TPS as far as midway through the range is concerned. The only way to test is by scan tool or ohm meter. As you would turn the tps, it would show an open in the circuit.

 

[Storm]

Replace the TPS.. I had a 2.3L Turbocharge in an 89 Mustang back in the day.. TPS always caused problems for me.. I changed mine 4 times..