# Diagnosing lag **URL:** \ **Category:** Maintenance/Repairs\ **Tags:** toyota, pickup\ **Created:** [September 26, 2026, 4:52am UTC](https://community.cartalk.com/t/diagnosing-lag/206302 "2026-09-26T04:52:13Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![RandomTroll](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/randomtroll/32/12184_2.png) [@RandomTroll](https://community.cartalk.com/u/RandomTroll)\ **Post date:** [September 26, 2026, 4:52am UTC](https://community.cartalk.com/t/diagnosing-lag/206302/1 "2026-09-26T04:52:13Z")
I’ve asked before, and responded to the advice I’ve gotten, but I’m back at it. My '87 (2WD, gas, carburetor, 5-speed) lags. It really matters when I have to start from a stop: I have to give it gas before I let out the clutch because the load on the engine causes a stall. The delay annoys people behind me and can be dangerous uphill. I take a roundabout route through the neighborhood on flat streets before I go uphill. I replaced the fuel pump, filter, fuel lines, plugs, coil, distributor, cables, air filter, oil and filter, and rebuilt the carburetor. Every time I buy gas I add a bottle of motor treatment or gas cleaner. The choke works. I’ve drowned the throttle cable and all the exposed workings outside the carb in spray lube. When I work the throttle by hand when it’s off and cold I see no gas coming into the carb. I begin every day I drive by priming the carb with carb cleaner or starting fluid; I don’t need to do that the rest of the day. Because I installed a new accelerator pump and auxiliary accelerator pump when I rebuilt they’re new and I expect them to work. I took them off the other day (and lost the spring and 2 bolts - grrr) and they look okay. I suspect the problem is earlier in the system. How do I trace back to see where the gas is first not-getting? I have a mechanical pump so I can take it off and work it mechanically; I’ve done that. I’d like to be orderly and efficient. ---
**Author:** ![Nevada\_545](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/nevada_545/32/41232_2.png) [@Nevada\_545](https://community.cartalk.com/u/Nevada_545)\ **Post date:** [September 26, 2026, 5:49am UTC](https://community.cartalk.com/t/diagnosing-lag/206302/2 "2026-09-26T05:49:08Z")
> [@RandomTroll](#): > > When I work the throttle by hand when it’s off and cold I see no gas coming into the carb. The accelerator pump is inoperative. Replacing the diaphragm is only part of the repair, the nozzle and check ball must be cleaned. There are passages inside the carburetor housing to be cleaned. It is not unusual to need to clean the accelerator pump after a year of storage. Apparently, this is the reason people sell their auto collections; they don’t have time to clean carburetors. (See old mechanic retires thread) ---
**Author:** ![pleasedodgevan2](https://avatars.discourse-cdn.com/v4/letter/p/ad7895/32.png) [@pleasedodgevan2](https://community.cartalk.com/u/pleasedodgevan2)\ **Post date:** [September 26, 2026, 6:30am UTC](https://community.cartalk.com/t/diagnosing-lag/206302/3 "2026-09-26T06:30:36Z")
I had a probleml like that and I had to properly set the float level to fix it. The fuel wasn’t reaching my pump piston because the slot was higher than the fuel level. Yours is a different setup if it’s a diaphragm but the float level may still be a problem. ---
**Author:** ![Mustangman](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/mustangman/32/44130_2.png) [@Mustangman](https://community.cartalk.com/u/Mustangman)\ **Post date:** [September 26, 2026, 1:05pm UTC](https://community.cartalk.com/t/diagnosing-lag/206302/4 "2026-09-26T13:05:54Z")
> [@Nevada\_545](#): > > they don’t have time to clean carburetors. They just don’t know about Riley’s Rebuilds. > **[Rileysrebuilds](https://rileysrebuilds.myshopify.com/)** > > Riley’s Rebuilds is a youth-led automotive business specializing in professional carburetor rebuilding, restoration and sales. Shop rebuilt Holley, Edelbrock, Rochester Quadrajet and Carter carburetors, rebuild kits, parts and automotive products... ---
**Author:** ![weekend-warrior](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/weekend-warrior/32/26122_2.png) [@weekend-warrior](https://community.cartalk.com/u/weekend-warrior)\ **Post date:** [September 27, 2026, 12:18am UTC](https://community.cartalk.com/t/diagnosing-lag/206302/5 "2026-09-27T00:18:22Z")
I would also check for vacuum leaks. Cracked/loose intake manifold bolts, vacuum hoses, and EGR vacuum modulator leaks. also, I found this. I think it’s the one you have. [Toyota 22R Carburetor Disassembly Rebuild](https://www.bitdrivencircuits.com/Toyota22r_Carburetor/toyota_22r_carburetor_home.html) ---
**Author:** ![davesmopar](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/davesmopar/32/41750_2.png) [@davesmopar](https://community.cartalk.com/u/davesmopar)\ **Post date:** [September 27, 2026, 1:13am UTC](https://community.cartalk.com/t/diagnosing-lag/206302/6 "2026-09-27T01:13:59Z")
Have you even checked your fuel pressure??? ---
**Author:** ![texases](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/texases/32/862_2.png) [@texases](https://community.cartalk.com/u/texases)\ **Post date:** [September 27, 2026, 1:18am UTC](https://community.cartalk.com/t/diagnosing-lag/206302/7 "2026-09-27T01:18:47Z")
With no gas when throttle opened there’s a problem with the accelerator pump, at least. I’d also check the float level and vacuum leaks. Seems the fuel pump works if the truck runs once started. ---
**Author:** ![Tester](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tester/32/15976_2.png) [@Tester](https://community.cartalk.com/u/Tester)\ **Post date:** [September 27, 2026, 1:39am UTC](https://community.cartalk.com/t/diagnosing-lag/206302/8 "2026-09-27T01:39:14Z")
> [@RandomTroll](#): > > Every time I buy gas Are you filling with E-10 gas? That stuff will destroy rubber parts in a carb. > **[How will E10 fuel affect older and classic cars | SUSTAIN Fuels](https://sustain-fuels.com/education/how-will-e10-fuel-affect-older-and-classic-cars/)** > > Learn about the effects of E10 fuel on older and classic cars. Discover potential risks and ways to protect your vintage vehicle with expert advice from SUSTAIN Fuels. Tester