[Funkman]

Hi guys

I'm new to this site and was wondering if anyone could help me with an issue. I've recently bought a Toyota Celica 1994 2.0 Gt St202 (going by the chassis) Japanese import. It was a non runner, started and stalled. The fuel pipes were leaking badly underneath the car too so I thought it could be due to air getting drawn in. I was hoping to fix it up and keep it as I've always liked the mk6 style. When I initially start it up the idle seems a lot higher than I think it should be. It idles around 1500rpm, it idles fine though. After around one minute it starts to slightly splutter then misfire and eventually cut out. I've temp repaired the fuel pipes to see if that would fix it before completely making new ones up, but it's still the same. I've replaced the distributor cap and rotor arm as they didn't look in the best condition as is, fuel filter. Coolant temp sensor. Tried a new ignitor. Tried a second hand fuel pressure release valve, distributor which my mate had from his Mr2 but no luck. The car is slowly killing me 😂 oh I also found a leaking capacitor in my ecu which I replaced but still the same. I managed to source a second hand ecu which came out of a running car, but exactly the same. Oh and there are no fault codes, to make it even more fun 😂 if you've made it this far, well done!! Any help would be greatly appreciated as I'd really like to fix this car up as bar the running issue and a few other mechanical things it's in great condition for its age and would be a shame to scrap it.

Thanks

 

[Sea-J]

OMG! These are the same issues I have/had except for the leaky fuel system. I'm still working on problems. Installed new sensors and switches and the problem persists. I did find that the throttle position sensor had a dirty contact so I cleaned that and the neutral start switch connector plug was badly corroded, one contact was totally gone. Now I'm waiting for that part to arrive in my mailbox so I haven't had an opportunity to run the motor yet since cleaning the TPS.
There is not much more I can replace, clean, or fix other than a new ignition switch. The car has over 268k and have read that the key switch contacts wear out and might not be making good contact causing the EFI to shut down. It's a money pit for sure but hang in there, the ugly problem will be found sooner or later. I'll keep you posted if I find a solution and hope you do the same.

 

[Funkman]

Hey. Thanks for getting in touch. Yeah, I've ordered a new tps as one of the resistance readings wasn't right when I tested it. Still waiting on this arriving. What else have you replaced? My car only has 91,000km on the clock so it's not a high mileage car. I haven't heard about the ignition switch though, maybe worth a try. I've also noticed that sometimes my interior lights, ignition barrel light too will light up sometimes and not other times. Could be irrelevant and a completely different issue but more information is always better than no information. I tried resetting the Ecu idle values tonight by disconecting the battery, pressing the brake pedal twice, waiting 30 seconds and reconnected the battery. But it's now just starting and cutting out immediately. But its no longer got the high idle....or any idle 😂

 

[Sea-J]

Replaced, fuel pump, fuel filter, NGK plugs, wires, dist cap, igniter, coil, PVS 160 vacuum switch, start injector time switch, fuel pump relay, battery, nss. Cleaned and tested vacuum lines, sensors and switches. The egr was plugged completely.
I do have a complete set of Celica repair manuals with specs. Since I've got spark, air and timing spot on the only thing left is fuel so now I'll begin a complete step by step trouble shoot according to the book. Something is stopping fuel flow, Now just have to find out what, Take heart in knowing you're not alone, I'll post any findings.

 

[Sea-J]

Forgot to mention it's a gen 5. Bought the car last July as a project. Previous owner blew the engine @ 200k and replaced it with a 3s short block and 5s parts so now I have to figure out what systems I'm working with. I call it my franken engine. It will be laid up for the cold winter season which gives me lots of time but I'm retired so it's a daily project.

 

[Funkman]

😂 yeah, but it should still work as there shouldn't be much difference with the block. You might want to check your fuel pressure release valve then. I've already swapped mine over but to no avail. I don't know what all of the differences are between the gen 5 and 6 but I've definitely not got a cold start injector. I've also ordered Asa n upstream O2 sensor as it failed the resistance test and that does effect the amount of fuel the ecu will add. Thanks and I'll keep you posted too 👍

 

[Funkman]

Hey. So an update on the car. I've finally fixed it, took longer than I expected......😂 I think I had a few issues. First being the icv, it was sticking slightly, second was the upstream 02 sensor and finally the spark plugs. So........what I believe was happening is when I initially started up my car it was revving very high (icv) as it got up to temp and came of fast idle it relied more on the upstream lambda for the air to fuel mixture, which had failed (resistance was far too high) and at this point the failing spark plugs weren't getting enough fuel for the weak spark to ignite. Well that's what I think at least 😂
I first stripped the icv and cleaned it out using throttle body cleaner and actuated the magnetic valve with my power probe until it was moving freely. I replaced the valve and started the car up. It wasn't revving as high but once it came of the fast idle the car was strughling, but not cutting out now.
I then replaced the faulty upstream 02 sensor and the car was idling a lot better, almost perfect. But when you revved the engine at the lower end I was getting a misfire. Not drastic but enough. So I replaced the spark plugs and 🙌 it's all good. Idiling, revving and driving like a dream. I hope this helps you out 👍

 

[Sea-J]

Friday morning took the ignition switch out to check out it there were problems there, not an easy job. Had to remove a good portion of the underside dash. Left side drive. Nice to have the convertible, lot more room to move around and hang upside down with my head under the steering wheel
After taking the actual switch apart, not the barrel, I found most of the contacts were so dirty they were lucky to make any contact at all. The dielectric grease that's used on initial install turned hard and dirty after 30 years...go figure. Sad part is when I took it apart little springs and ball bearings took a flyer never to be found again. I planned on purchasing a new unit anyway so now I'm forced to. The contacts that were really bad were the ones that went to the start and efi/ecu according to the wireing schematics. Maybe, just maybe this is a cause of our problems.
Should be about a week to get the new ign switch and install.
Will keep you informed when it's installed.
View attachment 31635 View attachment 31636 View attachment 31637 View attachment 31638

Hey. So an update on the car. I've finally fixed it, took longer than I expected......😂 I think I had a few issues. First being the icv, it was sticking slightly, second was the upstream 02 sensor and finally the spark plugs. So........what I believe was happening is when I initially started up my car it was revving very high (icv) as it got up to temp and came of fast idle it relied more on the upstream lambda for the air to fuel mixture, which had failed (resistance was far too high) and at this point the failing spark plugs weren't getting enough fuel for the weak spark to ignite. Well that's what I think at least 😂
I first stripped the icv and cleaned it out using throttle body cleaner and actuated the magnetic valve with my power probe until it was moving freely. I replaced the valve and started the car up. It wasn't revving as high but once it came of the fast idle the car was strughling, but not cutting out now.
I then replaced the faulty upstream 02 sensor and the car was idling a lot better, almost perfect. But when you revved the engine at the lower end I was getting a misfire. Not drastic but enough. So I replaced the spark plugs and 🙌 it's all good. Idiling, revving and driving like a dream. I hope this helps you out 👍

That's great news. Glad you found the problem(s). Now I'm hoping next week I can say the same.

 

[Sea-J]

Friday morning took the ignition switch out to check out it there were problems there, not an easy job. Had to remove a good portion of the underside dash. Left side drive. Nice to have the convertible, lot more room to move around and hang upside down with my head under the steering wheel
After taking the actual switch apart, not the barrel, I found most of the contacts were so dirty they were lucky to make any contact at all. The dielectric grease that's used on initial install turned hard and dirty after 30 years...go figure. Sad part is when I took it apart little springs and ball bearings took a flyer never to be found again. I planned on purchasing a new unit anyway so now I'm forced to. The contacts that were really bad were the ones that went to the start and efi/ecu according to the wireing schematics. Maybe, just maybe this is a cause of our problems.
Should be about a week to get the new ign switch and install.
Will keep you informed when it's installed.
View attachment 31635 View attachment 31636 View attachment 31637 View attachment 31638

That's great news. Glad you found the problem(s). Now I'm hoping next week I can say the same.

The new key switch I installed worked but another issue popped up. The dizzy tested bad on one side so now I have to wait for a new one. Not as lucky as you I guess.