RLS7201 wrote:
Gdetrailer wrote:
pilotanpia wrote:
MT BOB wrote:
Lots of F53-460 fuel pump problems, and threads,on the net.
2 things you can try,cheap and easy,replace the TFI and the fuel pump relay.
Other things to try- at your risk- when it acts up,1-loosen or remove the fuel cap
2- when it acts up, throw trans in neutral, turn off and restart engine.
I tried the TFI aka Ignition Module which is located on the front apron between the left headlight and radiator. So, not exposed to engine compartment heat. Bottom line, it did not resolve the issue.
Thank you.
TFI is only one part, there is the ECM (Engine Control Module) which is the "computer" or "brain" that controls ignition timing and fuel delivery to the engine. ECM has predefined fuel and ignition maps and uses a variety of external sensors (some which you have replaced) to determine timing and fuel delivery.. ECMs where often mounted in the engine compartment near the windshield, not sure where it is on a Chassis build.. Failing ECMs can affect engine performance..
ECM on OP's chassis is on the inside of the fire wall, just in front of the steering column. Not exposed to engine heat.
Richard
Good to know, however, "heat soak" can still apply to the ECM even if is living a a cooler environment. This is especially true if there is failing components inside the ECM (which may be surrounded with potting material which is supposed to reduce vibration and moisture damage to the ECM). If it is potted, it makes heat dissipation of the internal components much slower. Parts tend to heat up faster and stay hotter than they were designed to be at.
OP has a 26 yr old vehicle, fair chance there are failing capacitors, semiconductors or even "cold solder joints" in the ECM at the least..
Op already has changed pretty much every electronic part within the engine compartment without change to the symptoms. ECM is a common part that controls not only ignition but the fuel delivery which will affect engine operation and performance.
I would also suggest taking a look at all of the wiring harness ground connections, not unusual for vehicles of that age to start having failing ground connections and it only takes one corroded ground to foul up the works.
