Newbie orientation

[daivddd]

I need basic help figuring out how to find the right forum in which to post. I need help with my 2000 Explorer 5.0L ignition, maybe the MAF, ECM, or circuitry diagnosis. It starts, sometimes idles, sometimes accelerates, starts coughing. Very irratic and I don't know where to start. If Classic Broncos isn't the right place I should be, maybe someone can direct me somewhere more appropriate. Thanks.

 

[ba123]

I'm sure there is someone that can help you here.

I would venture to guess it's your TFI module as they commonly go bad but I haven't dealt with that ignition stuff in a while so only a first thought from me. I have had one go bad in years past and think it was some behavior like that.

Google Ford TFI module testing and see or maybe someone else will respond with something else.

 

[SteveL]

Give it a few days. There's plenty of guys on here who have done the swap

 

[daivddd]

Thanks, ba123, then I'll look into the TFI and elaborate a bit more here. I installed a new MAF and cleared all codes (disconnected the neg, connected positive to neg lead for 5 mins) of my 2000 5.0L. It started fine and I idled it for 5 mins, then I ran it for another 3 at a bit higher RPM and 3 more at a rather high RPM. It all sounded good. I returned to idle and stepped on it and it choked badly. With much throttle maneuvering it recovered and I got it running smoothly at a high RPM. Then I floored it and it sounded like turbo charge kicked in and RPM slowed then it choked out and died. It sounded like bad backfiring in the air cleaner. I could not start it again until I disconnected the MAF and it started immediately, but just touching the pedal killed it. It then would not start again until I reconnected the MAF and it started fine. Sometimes it accelrates smoothly, and other times is sounds like gasping and I have to jab the throttle in and out for it to speed up. The same process repeats each time. Coincidentally it maintains good fuel pressure, voltage checks good in the TPS, and I can't find any vacuum leaks. There has been some wiring damage so perhaps circuitry to the ECM was effected. I could run diagnostics, but I don't know where to start. Can anyone steer me in the right direction?

 

[ssray]

If you use google you might try this…might get more than the forum search function. Google doesn’t seem to let you use a hyperlink so you need to copy into google.

site:classicbroncos.com ford 5.0 liter tfi module

 

[daivddd]

Questions of the TFI! It seems to me that if it starts, idles, and revs up fine sometimes, the coils and distributor (TFI) are working fine. But is TFI known to be intermittent? I don't want to buy expensive parts just guessing.

It starts and runs better with the MAF disconnected! However, at relatively high RPM if I step on it I get the turbocharge sound, cutting out and backfiring in the air filter, then it dies. At that time I cannot start it again until I plug in the MAF, but then unplug it to run better until I rev up fast again. Does that make sense to anybody? I wonder if either my new MAF is not suitable or if its circuitry has failed.

 

[904Bronco]

Tell us what harness you are using and if you modified the factory harness yourself or had it done, by say EFI Guy?

 

[daivddd]

It's all stock except the new MAF.

 

[daivddd]

It's all stock except the new MAF.

Today I scanned PO113, PO118, and PO453, so I have some things to look into now.

 

[daivddd]

Today I scanned PO113, PO118, and PO453, so I have some things to look into now.

In addition, there has been seemingly unrelated wiring damage under the dash and in the vicinity of the ECM. That's why previously I questioned circuitry damage, so I need to know how to test critical ignition components that may cause MAF-type symptoms I've described.

 

[904Bronco]

So a completely stock 2000 explorer harness, with the matching ECU, and you are making a complete transfer of all the related systems/components, with nothing deleted, into an early bronco. With some possible wiring damage in the main harness...

 

[SLOWnEASY]

Have you inspected the wiring damage? Do you know what caused the damage like was it rodent chewing or possibly accident related from the donor vehicle? Are the wires or insulation broken or is it just the outer loom that's damaged? It could be totally unrelated, or is could possibly be the cause of your issues. At the very least I would start the Bronco and pull the codes. Then wiggle and tug on the damaged area of the harness and see if the codes change.
Oh and I second 904Broncos' question above ^^^

 

[daivddd]

In seems I may have complicated my messages! No Bronco is envolved. I have a 2000 Ford Explorer 5.0L all stock, and someone broke in and stripped out the flasher and did some minor (I thought) wiring damage. It ran fine before then sat for a long time, but now it runs except for ignition problems. The MAF acts eratic; sometimes the engine only starts with it disconnected but backfires upon acceleration and gasps then stalls unless I plug it back in. Even then I get the turbocharge effect upon high RPM. Sometimes it will only start with it disconnected, sometimes only when connected. I replaced it but that did not help. Basic voltage tests at the MAF pass OK. OBD-II codes revealed are P0113, PO118, and PO453, so I'm trying to figure out how to resolve those now. I suspect, however, that I have a bigger problem.

 

[daivddd]

Some wires wire found with bad connections due to age, such as to the fuel shut-off, window switches, and battery saver system. I resolved them all, but I may be overlooking other faulty connections elsewhere!