Engine surge at idle and now highway

I have always has a slight idle surge on my 95 BRONC when stopped at stop lights. recently the idle surge has grown into a surge on the highway. The engine feels like it is going to stall out at 55-75 mph. It makes a knocking noise in one of the pulleys up front but not sure which? I have read a lot of threads on the subject and now it is my time to face the music. Any help from experienced BRONC owners? My 95 is a 5.0 with 150k. I have recently rebuilt the front end and installed new spark plugs. Thanks,

That is often caused by a bad TPS (Throttle Position Sensor). Have you tried pulling codes?

Good luck,

>-

I havent tried to pull codes. I only know how to pull codes on an ODB-II. I changed the plugs last week and they were in bad shape. I have wires coming from amazon along with many other parts. I just purchased a cap and rotor.

Would a faulty TPS effect the surge I have had at idle or only at highway speeds? The TPS and The idle air control adapter, from reading these threads, seem to be a common source of surging problems. I needed new plugs, wires, cap and rotor anyway so I figured I would start there. The highway surge appeared to become worse after I changed the plugs and not the wires(cause I am waiting on them from amazon).

Thanks for the help and I will keep informed of the progress.

Seabronc said:

That is often caused by a bad TPS (Throttle Position Sensor). Have you tried pulling codes?

Good luck,

>-

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I changed my dist cap and rotor and good lord the engine is running smooth. but i still have a miss. The miss is not as pronounced as before but its def there. I get slight hesitations around 35-50mph as well as a miss when at stop lights. The dist cap and rotor where huge otherwise the others were well worn out. Its been awhile since I gave the BRONC some love

One of my spark plug wires is torn to shreds and I am waiting to see what improvements I get when the new wires get here in a couple days. I really appreciate a site like this and all the time you guys spend in here trying to help out others, like me, that love this truck. Doesnt matter what I own/drive otherwise, I will always have a BRONCO. Looks like da zone maybe a good place to try and pull codes from the ODB-I. The battery light starts to come on now(started a couple days ago when I put new plugs in) but it goes away after a min. New battery last year so id be surprised if that was the cause. I love this stuff, with your help I have no doubts I can get my rig running smooffffffff. I bought an igntion control module but havent installed yet.

Sounds like you have it knocked. If you have a b ad wire, it is probably the source of the remaining problem.

Good luck,

>-

Sup fellas,

Thanks for the help here. Thankfully it was a simple as a plug and wire replacement. The wires had been run incorrectly which had been causing my idle surge for the last 3 years. Sweet Lord she is running good....