Haha Isn't that the truth ... this truck and I have a love/hate relationship but the encouragement is very much appreciated. Thank you.

None of the rocker bolts or push rods were touched -- everything stayed in place just as it was aside from lifting the valve covers and putting new gaskets on. It certainly sounds like valve train tick, frequency picks up when revving and then comes back down as RPM falls. I'll see if I can update to post a short video when I get home this evening.

 

I sprayed a few squirts of CRC MAF cleaner on the sensor itself. There's a new air filter in place and I shop vacced all the leaves and crud in the filter box when I changed that out. No other blockage that I could see but I'll double check it this evening to confirm.

 

can you narrow down which side you hear tick, and use a piece of hose stuck to your ear and narrow down which cylinder it is, may have to remove that valve cover, and check if a rocker arm nut loosened up somehow, could put Marvels Mystery Oil in run for about 10 minutes, and change oil and filter, some crud could have clogged oil passage hole, when you was changing gaskets, some put Lucas Oil treatment in and it quieten noisy lifter/rocker arm

 

Hmmm. If it’s not the valve train, the only other thing I can think of is an exhaust leak. Did you say you recently replaced the o2 sensor? I’m sure this is a long shot, but are you certain the fan isn’t rubbing on anything, perhaps the black plastic radiator shroud?

 

Could be as simple as a lifter leaked down. It happens from time to time. If that's it, it should pump up in less than 10 minutes.

 

I'm pleased to report the ticking is resolved! I went back through to recheck my work and discovered one the spark plugs had to be snugged up a little tighter. I'll celebrate the small victory! Lol

So I've taken a short video of the other item I've been chasing: I'm not touching the gas peddle at all in video, that's entirely the truck doing it by itself. Once the RPM levels out after start up it acts like a vacuum issue but two mechanics have told me the vac system checks out. I have done a lot of reading about PSOM cluster problems on these trucks, but just about every one I've read said the speedometer needle is the problem sending bad signals to the PCM, versus a bouncing tachometer needle like I am experiencing. I have pulled the cluster and visually inspected it -- didn't see any burns on the board, capacitor leaks, broken solder.

I've taken the truck out for some errands and drove for about an hour. The cleaned injectors do seem to have improved performance -- much more responsive when on throttle. Pinging is still present, but I haven't tried MMO or Seafoam or the like yet. Plan is to check timing today when I have a chance.

I do wonder, if mechanic had not taken the SPOUT off when they adjusted timing, could that be a cause of an issue?

AND a new curiosity ... for kicks I braked hard to see what the truck would do. Interestingly the motor started to die, RPMs dropped, swung back up, dropped, swung back up, dropped and then the truck died. It did this twice. Checked codes and got 121 and 212, which I already know about. New code 332 which is related to EGR, so that's a new one I'll have to figure out.

 

Double checked the air intake to box and then to plenum and don't see anything to suggest blockage, just a lot of dust along walls of air intake to box. The rubber after the T to throttle body looks aged, but no cracks or anything that I can spot and the hose clamps are nice and tight.

 

Is that just the needle bouncing or an idle surge? If it's an idle surge, does it happen all the time, or start a minute or so after cold start and smooth out as the engine is closer to being warm? If it is doing it after start then quits after warm up, good luck. I've chased that problem since 1991 with no resolution. I have tried many things and spent a lot of time on it. I finally just gave up and live with it.

 

It's a surge, the RPMs fluctuate alongside the needle. When the motor starts, the RPMs climb and then level out as mentioned and things seem perfectly fine. After that is when it starts to surge. Engine temp doesn't seem to make any difference. It's odd because there have been a handful of times (no more than five instances) where the needle is smooth as can be and the engine is smooth as can be for no discernable reason. Otherwise the surge happens every time.

 

dfizzle2435 when you put new IAC, new TPS, did you check that the min/max volts on TPS wasnt off? when motor is warm, is idle still that high? quick way to check IAC with motor warm and running, is unplug IAC and see if motor tries to die

Fuel Injection Technical Library » Throttle Position Sensor (TPS)

How to Clean and Test your IAC - Ford Bronco Forum

 

I'm telling ya, drop in a bottle of Gum Out or another cleaner with PEA in it.. it will de carbon the insides and then run MMO in it. As i said my fave is RedLine SI-1 and then 3 to 4 oz of MMO per 10 gallons and it works like a dream. Check your TPC and IAC. especially check the gasket for the throttle body. 2 bucks and 4 bolts could fix the vacuum leak

 

Definitely will try the MMO and Redline. Throttle body and EGR have new gaskets on em. IAC and TPS are brand new Motorcraft, but I know I need to adjust TPS per the 121 code. Waiting on meter to come from Amazon. Appreciate the ideas and will keep digging! Haynes manual due in mailbox a week from today as well. Appreciate the ideas and will keep digging!

 

I had my truck a day and already had a haynes manual and ordered a code scanner for it. both are in the truck now, tucked under the seat. Gotta keep the Ol' Gals happy,and they do get cranky now and then.. I can only handle one cranky ol'gal myself.....I lost one of them but I still got my truck

I put the whole bottle of Redline in one tank, and dosed the other tank with MMO and now a year later have been doing the MMO treatment fairly religiously. I buy it by the quart, a cpl quarts at a time and then portion it off into thos 5 hr energy drink bottles. Got a plastic coffee can full of them in the bed of the truck. The sweet spot for my truck is about 3 oz per 10 gallons. I don't use it for mileage increase, but it happened, picked up about 1.5 to 2 mpg after the rediline / MMO treatment. I swear by MMO..

 

I used the round file, for chainsaw chain sharpening, and just file on one side of each hole, so you dont take chance on breaking plastic hole for screw, trying to drill out, it doesnt take much on each screw hole to get adjusted

 

There is always the possibility the TPS is not engaged with the throttle arm that moves the TPS. I always tilt the top of the TPS away from the intake a bit as I place in onto the throttle body, then rotate back to where the screws will line up. If not paying attention, the throttle body arm can get in front of the TPS tang and the TPS will not move with the throttle.

I always drill out the mounting holes so I can set my TPS. My truck may be strange, but the best overall voltage at closed throttle for me is .92. It seems to have a little better road power around .98, but is much more prone to stall out at takeoff with my manual transmission.