Zachattack88

I知 getting a hesitation while I知 cruising at different speeds 0-70. It is a intermittent hesitation with no particular pattern. I have ordered a new TPS to install. Any suggestions or input?

DarrinT04

Do you know for sure if the TPS has failed? There are many things that can cause sudden hesitations while moving

88xlt

I had that problem with my '88 F-150 with the 4.9 and 5 speed. I put a bottle of fuel injector cleaner in one of the gas tanks and it cured the problem in fairly short order. Your results may vary.

Zachattack88

I also have a five speed. I changed the in-line fuel filter underneath the drivers floor board and the fuel filter numerous times I thought I may have broken loose some tank rust after adding a bottle of seafoam to the front tank. That痴 where it all began about five months ago. I change the fuel filter and it was good for about two weeks then I changed it again and it was good for about four weeks then I changed it again but it didn稚 make any difference I致e been change the in-line fuel pump because it kept whining. I have the TPS arriving on Friday morning I also have a fuel pressure regulator to install. At the price of these parts I figure trial and error isn稚 a bad idea given the age of the vehicle

Zachattack88

I will try fuel injector cleaner. Do you recall what brand you used?

Steve83

No, rust is not affected by Seafoam or other solvents.That should have been a big clue that your guess was wrong.Sound is not a diagnostic criterion for the fuel pump.It's a VERY bad idea, especially if you're installing cheap parts. The originals are the highest-quality you'll ever have - most replacements are GARBAGE, and will make the truck run worse &/or less-reliably. Moreover; it's an antique truck - disturbing its old parts & electrical connections is likely to do more damage that you'll then have to repair. And that truck in particular has VERY fragile wiring. Click this & read the caption:


(phone app link)

Never change any part that's NOT due on the maintenance schedule, and HASN'T failed a published test. Get a Haynes manual, and read it cover-to-cover at least once:


(phone app link)

If you suspect any fuel system problem, the first step is to measure the pressure with a gauge:


(phone app link)

I highly recommend you put back every original part you still have, and either begin real diagnosis, or pay someone who can. It'll cost you less & take less time than continuing to throw part$ at it.

The best fuel system cleaners are Berryman's B-12 pour in, and Chevron Techron. Most others are wastes of money.

Zachattack88

I really have only replaced parts that needed it such as the radiator, power steering pump, alternator, idler pulley assembly and in line fuel pump anc filter, spark plugs and wires. I致e only started this trial and error thing with plugs and wires.

Zachattack88

I have been putting on Napa Gold parts as I get them at a reduced price. So I should technically use only Motorcraft when I do?

Steve83

MotorCraft is just a brand, like NAPA Gold. Both are made by MANY manufacturers in many places (including China), and some of their parts could come from the same manufacturer. The same manufacturer who might make cheaper parts for other brands. But generally: the premium-branded parts are built to higher standards (even if they come off the same assembly line as the cheapos) with better QC than garbage parts.

In any case (and including plugs, wires, & fuel filters): if there's no specific reason to change it, don't. If you have a specific reason (OTHER than due on the schedule), TEST it first. If it passes, there's no point changing it, and a few reasons NOT to. If you do change a part that failed a test, TEST the replacement the same way ASAP. If it fails, it's either a bad new part; or you tested it wrong, and you probably tested the original wrong, too.

Zachattack88

I have a mobile tech coming to diagnose the hesitation today. I will post later about what he found to be the cause.