Strange hesitation around 2500-3000 RPM | 85 22R-E

[SynthOkami]

Hey all, I'm having a weird issue with a hesitation on my 85 Celica GTS. I'll go ahead and list off all the parts I've put on down below. I'll also to get a video of what it's doing tomorrow, as well as a walk around of what all's been done.

The hesitation is rhythmic, and it only happens when the car has been driving for a minute, and it only happens on WOT. It like revs but there no power, and then it rhythmically jerks, like baaaaa- baaaaa- baaaaa- almost EVERY TIME at around 3k RPM.
It also pops down low around like 1000-1800 RPM or so when you first start trying to drive it. It idles great when you first start it and even when it gets up to temp as well. No misfiring, surging, or anything of the sort. (It used to misfire bad before some of the ignition and fuel related parts I put on.)


Fuel System: New 60 GPH fuel pump, fuel filter, fuel pressure regulator, and I've run a couple different Lucas injector cleaners through it like 5 times. (Side note, it doesn't care what octane fuel you use either.)

Ingition: All new dizzy stuff (Cap, Rotor, and O ring), coil, NGK plug wires, and I had NGK V-Power plugs in there, but it overheating all the time, and the bent valve it had kinda made those die really quick. So there's a set of NGK G-Power plugs in there right now. I ordered V-Powers and the G-Powers came in and I was already home and I wasn't about to drive 30 minutes back to that store I bought them at so I just used them anyways (Lemme know if those would be an issue. It's run with them just fine before this started happening.)

Sensors and Electrical: All new OEM TPS, a new Bocsh O2 sensor (it's a one wire, idk if that would make a difference. It was acting up before I put the new O2 sensor.) I have a new TPS plug as well, but I haven't put it in. The old one falls out and it's held in with zip ties at the moment.

Engine: I've checked the timing chain and it's brand new. All the guides are literally mint and the little tensioner works great too. It's set properly as well. I did a full head gasket on it, with new gaskets on everything that was removed. I also had the head rebuilt and got 1 new intake valve (because it was bent) and 4 exhaust valves (they were mushroomed out)
 
Other: New clutch, New battery, New alternator, New Rad, and I saw that the set screws for the throttle body are missing. So I put in new screws for the throttle body, the one that keeps it from sticking (the one that you use to set the TPS) and the set screw little return thingy that you can push down on the back of the throttle body I replaced too.

The things that've been put on since the hesitation are the O2 Sensor and TPS. And the last thing I did before it started having this hesitation was the fuel pump (and we know what happened with that).

So I'm eye-balling the ignitor, or a sensor I could've missed, I'm gonna get some new vacuum lines and a PCV because it looks like garbage and leaks bad. Something MAY up with the fuel pump still. After I replaced the fuel pump it worked for about a month, and then it started this hesitation.

Lemme know what you guys think. I'll post a full video cold starting it, showing warm idle, driving it, and hopefully getting it to misbehave so you can see what I'm talking about.


Thanks!

[sirdan]

I feel like its something spark related. But if you have a fuel pressure gauge it wouldn't hurt to hook that up and try to see what happens when it miss fires. Have you checked your timing? maybe it got advanced too much and it pings and pulls timing causing the issue. I don't know how the timing map is on these but I bet all the timing advance is in right around 3k.

[SynthOkami]

I've made a discovery. I went to try and start it to move the car today, and it wouldn't start at all. and I tested around and I was getting spark. I looked around, and didn't see anything out of the ordinary. I did a compression test just for peace of mind and we were floating around 180~ so the engine has A LOT more compression after rebuilding the head and doing that head gasket. So I went inside and was thinking, and I thought to go check the fuse for the fuel pump. Sure enough, it was blown. (For context, my dad helped me out with the fuel pump cause it was getting late when we were installing it. He installed the pump backwards, and so he decided to just cut the wires and swap them on the pump harness, and the car started right up.) Looked back there and one of the connections had come loose. Crimped it back together, and it's still blowing fuses. We disconnected the pump and tried to start it and the fuse didn't blow. So I think I'm gonna have to drop the tank again this weekend and try to have a look around in there.

[SynthOkami]

Well... The fuel tank was nasty and VERY rusty, and had clogged up the strainer with rust chunks and powder. And I'm pretty sure it ruined that pump. Then I deep cleaned the tank, and got everything cleaned and put back together. When I went to start it, it started up okay. So the fuel issue seems fixed now. But, the hesitation is worse now with the pump fixed, especially on throttle. So I'm pretty sure sirdan was right about something being up with ignition. The only thing I haven't replaced is the ignitor. But we tested it a couple months ago and it was in spec. But we had taken the Celica to a shop to try and fix an issue with starting that we had after replacing the head gasket. And they messed with the dizzy and said "it was off" and didn't really elaborating further on it even after we asked. But I don't think they're the most competent people, because if they looked at it with a timing light, they'd clearing see how advanced the timing was set and should've gone uhhhhh that's not right. But it was still set super off when I got it back so I dunno what they did, and I haven't checked the dizzy since. So next on the list is check dizzy, check/replace ignitor, check/clean/replace AFM, and I'm gonna do an EGR delete after I get everything running correctly.

[SynthOkami]

AFM is good, dizzy is set properly, plugs are good, and I did an EGR delete. Still runs like crap. I got a knock sensor on the way, and I'm gonna check the engine timing. I'm sure we double checked it like a million times when doing the head gasket, but I'll take a look at it when it's not bad weather.

[ozzie]

Can you get it past 3k rpm, or does it just stop there? What's the situation with the catalytic converter? If the cat is plugged it won't be able to push exhaust out, so it will get to a point where it just refuses to rev.

[SynthOkami]

It goes past 3k, but it only can rev past it when you first start it. The longer the engine is on the worse it gets, and it isn't a issue with engine temp, because it misfires while it's cold too, just not nearly as bad. It's almost like the more times you go wide open throttle the worse it runs. And if you drive it and hit WOT the car stalls completely and it's like all fuel cuts or all spark cuts and the engine is only still spinning because the car is moving. So as soon as it cuts out and you stop, the engine's dead.

The latest update of parts is a new OEM knock sensor, PCV, LCE EGR delete kit, and an Accel coil.

Another thing, I checked the ignition module, and it checks out.

But one strange thing my dad found while probing and looking around, was that the EFI and MAIN relays are getting really hot for like no reason. They still click like they should, and the car still turns on, but when they start getting hot the car starts running like crap. I checked the wires for the fuel pump, injectors, dizzy, TPS, AFM, coil, and could not for the life of me find another wire that's getting hot like the relays are. And I checked all the front harness wires for bald spots, and checked some of the grounds, still nothing.

I also am going to get a video of how it runs to post on YouTube, here on this forum, Instagram, and I'll try to find the Celica FB page one of my Instagram followers was talking about.
Cause I don't think making forum posts without some kind of video is very helpful lmao.

[SynthOkami]

Here's an easy to read updated parts list:


P A R T S :

NGK plugs
NGK plug wires
Accel coil
distributor rotor
distributor cap
battery
alternator

replaced missing set-screws and nuts for throttle body
OEM TPS
OEM knock sensor
Bosch O2 sensor
fuel pump
fuel pressure regulator
fuel filter

timing chain and guides
head rebuild (new seals, 1 new intake valve, 4 new exhaust valves)
head gasket
stock replacement rad
rad hoses
coolant temp sensor
OE PCV
replaced "some" vacuum and coolant hoses

Exedy clutch
LCEngineering EGR delete


O T H E R :

cleaned intake manifold from EGR build-up (it's still gross, just not that bad.)
cleaned throttle body
cleaned gas tank
checked timing (ignition and chain)
checked ignition control module (IGM)
checked vacuum leaks

current compression: 180psi~
current ignition timing: 5


N E X T  O N  T H E  L I S T :

check and then clean/replace AFM (Air Flow Meter) if needed
check ECU and possibly replace it
re-check TPS adjustment
install new EFI and MAIN relays when they come in

[ozzie]

Your symptoms sound like they could be plugged up exhaust system. For testing purposes, disconnect the exhaust system after the manifold and take it for a spin.

I'd also check fuel pressure, and if it's good, I'd probably try to find another ignition module before replacing the ECU.

[SynthOkami]

Heh heh..  it was uhhh... Fuel pressure alright. I didn't put enough gas in it. I kid you not, I got a 5 gallon gas jug, filled it was 93, took it to the nearest gas station, and I've driven the car all day LOL. Oh and the car is cat-less. I already straight piped it trying to get it to run better. TO BE FAIR, I put like around 2-ish gallons of old-ish 87 in there. But I guess some of the most annoying things in life have easy fixes. But GOD I feel like a damn moron.

[SynthOkami]

TO BE FAIR, It did the EXACT SAME THING with a full tank before I fixed the fuel pump. I just didn't add back enough AFTER I cleaned the tank and fixed the pump. So that's not be being stupid and not adding gas, because I did. I just didn't add more than 1 1/2-2 gallons.

[twotone_ra64]

"Always measure twice, and cut once!" Wait, that's not it... "The simple and familiar hold the secrets of the complex and unknown." Agh, I'm terrible at this.

Well, although it may have been frustrating to have to realize the solution was so simple, you at least have most of the consumable parts of the engine replaced now, and that'll certainly give you some peace of mind hereon!

[sirdan]

I was using this POS snowblower this winter, got it working real good. I did half the driveway and it quit on me. I looked in the tank and it had gas, cleaned the carb 3 times and couldn't get it to run. Did the rest by hand and let it sit for a month or so until it snowed again. I decided to attempt to fix it again cleaned the carb again with no luck. I was less frustrated this time so I did some better troubleshooting. I checked the float to make sure it was set at the right level, well no fuel would come out at any level. Then I took the line off the carb and no fuel again. Then I took the line off the tank and there is no fuel straight out of the tank petcock. Meanwhile the tank is 1/4 full. Put more gas in it and it flowed fine. The tank is a piece of shit and the last 1/4 tank of gas doesn't drain down the petcock. So all this dicking around and I just needed to add fucking gas!

[SynthOkami]

I'm honestly happy it motivated me so much, and I got the car to a point to where I feel like it's actually admirable. I detailed it, replaced all but one engine maintenance item (Air Flow Meter. cause it works fine.), and the car has never looked, sounded, and drove this nice. It literally feels like a bough a new car with all the work, maintenance and mods I did. The interior feels like a million bucks, it smells and looks sooo much nicer, it rattles less, I could go on and on. I'm so happy with the car now.

Next on the list is three new U-joints, out-put and diff seals, and center support bearing! I got 'em, I just need the time now.

I should post some REALLY nice pics of how it's looking on here to show some of the progress.

Thank you all so much for your help as well! I know I thanked most of the people that helped on Instagram already, but this forum has so much useful info.

[twotone_ra64]

I detailed it, replaced all but one engine maintenance item (Air Flow Meter. cause it works fine.), and the car has never looked, sounded, and drove this nice. It literally feels like a bough a new car with all the work, maintenance and mods I did. The interior feels like a million bucks, it smells and looks sooo much nicer, it rattles less, I could go on and on. I'm so happy with the car now.

Clean cars run better!

Thank you all so much for your help as well! I know I thanked most of the people that helped on Instagram already, but this forum has so much useful info.

I'm so happy you found the value in our little forum! I wish folks would flock to it like the old days, and Facebook groups weren't the norm.