4G93 DOHC Problems

[sanekit]

whoaaaaaa that's cheating noise with noise! was on DUKE just now, the dial up noise was indeed overwhelmed or in fact, muted by the exhaust lmao! so wrong but so right



engine not healthy.. piping white smoke.. my fund is near to do full overhaul, but friends around me keep poisoning me to drop new head

UPDATES on AC/Idling problem: had my alternator charge rate checked, normal. AC compressor is the correct spec (15C) so that factor is eliminated too. the foreman tested a few spots, made sure the AC system is working fine and suggested it could be the throttle body (back to square one). this isn't his forte so he said best i look for friends who have similar rides to troubleshoot.

called this mechanic in sri kembangan, got my car fixed there once and he is one enthusiastic guy who's crazy over 4G engines, owns a mivec too. anyways, he said the problem could only be around the throttle body area. confirmed by few mechanics already, glad that its narrowed down to that area now :proud: will get it resolved soon. at the same time, jaring is still dialing up in my car :stupid:

I thought you already fix the TB? Time for top overhaul and mivec TB.

 

[sweelt]

parakey. good info, adjusting tps. Using multimeter. Can diy.

 

[vr2turbo]

Car dialing for help......lol but dial up too slow.....hhahhahahha

 

[sanekit]

Car dialing for help......lol but dial up too slow.....hhahhahahha

Time to upgrade to TIME 100mbps.

 

[drummydrew]

Have you tried this > https://www.ozvr4.com/threads/iacv-idle-air-control-valve-test.15362/page-2#post-333458

very informative and helpful, thanks alot! i'll try working on that when i meet my friend who has the multimeter.

I thought you already fix the TB? Time for top overhaul and mivec TB.

only clean serviced it last time, the most recent is fitting a new stepper motor to troubleshoot it. feels the same as the old one - bad idling still. if mivec TB what adjustments do i have to do? overhaul yes!! but i am also skeptical cos this engine has been overhaul 2-3 times (done badly) which contributed to its current condition - leakage, white smoke, dented pistons..

Car dialing for help......lol but dial up too slow.....hhahhahahha

sho slowww like its never connecting:slug:

 

[sanekit]

only clean serviced it last time, the most recent is fitting a new stepper motor to troubleshoot it. feels the same as the old one - bad idling still. if mivec TB what adjustments do i have to do? overhaul yes!! but i am also skeptical cos this engine has been overhaul 2-3 times (done badly) which contributed to its current condition - leakage, white smoke, dented pistons..

Wah. Changed new stepper motor still having bad idling? Should go back to the shop that install the stepper motor. Most of the time it's the TPS sensor not adjusted correctly. If you're up to some DIY session and have a digital multimeter, you follow the steps from the site link below:

http://www.diytacra.com/2012/12/tps-idle-switch.html

http://www.diytacra.com/2010/07/tps-adjustment.html

Dented pistons not good. I would be very very worried to drive the car knowing that it's in that condition.

EDIT: For Mivec TB, you need to bore the intake manifold just a lil bit coz it's slightly larger than your stock TB.

 

[drummydrew]

Wah. Changed new stepper motor still having bad idling? Should go back to the shop that install the stepper motor. Most of the time it's the TPS sensor not adjusted correctly. If you're up to some DIY session and have a digital multimeter, you follow the steps from the site link below:

http://www.diytacra.com/2012/12/tps-idle-switch.html

http://www.diytacra.com/2010/07/tps-adjustment.html

Dented pistons not good. I would be very very worried to drive the car knowing that it's in that condition.

EDIT: For Mivec TB, you need to bore the intake manifold just a lil bit coz it's slightly larger than your stock TB.

now that you mentioned and provided the links, i reckon it's very likely the TPS sensor. mine is a 4-pin. now im getting a clearer picture of it, can't wait to work on it tomorrow!

yesss dented pistons ain't cool! but only on the top part where the combustion happens. 2 mechanics said based on the marks they're still usable, so imma live with that until the engine is opened up the next time then access what needs to be replaced.

MIVEC TB measures at 70mm? if the stepper motor doesn't solve it tmr, then i might be looking into TB shopping soon :hmmmm2:

 

[sanekit]

now that you mentioned and provided the links, i reckon it's very likely the TPS sensor. mine is a 4-pin. now im getting a clearer picture of it, can't wait to work on it tomorrow!

yesss dented pistons ain't cool! but only on the top part where the combustion happens. 2 mechanics said based on the marks they're still usable, so imma live with that until the engine is opened up the next time then access what needs to be replaced.

MIVEC TB measures at 70mm? if the stepper motor doesn't solve it tmr, then i might be looking into TB shopping soon :hmmmm2:

I think most likely it's the TPS settings. Happens to me before. I changed ISC for my TB (mine is 93 sohc). But the idle sometimes hunting, sometimes high, and got hesitation when i accelerate. Send back to the guy (he sells stuff here ZTH id DDT), he checked my TPS was not correct and set back then all was good. But now I swap to a larger TB dy. Haha

Your cylinder walls all ok ah after what happen to your engine?

 

[drummydrew]

I think most likely it's the TPS settings. Happens to me before. I changed ISC for my TB (mine is 93 sohc). But the idle sometimes hunting, sometimes high, and got hesitation when i accelerate. Send back to the guy (he sells stuff here ZTH id DDT), he checked my TPS was not correct and set back then all was good. But now I swap to a larger TB dy. Haha

Your cylinder walls all ok ah after what happen to your engine?

awesome! good to know that you dealt with DDT before, if he solved yours then he should be able to solve mine cos the ISC is from him if really TB issue then i'll be looking to get a bigger one too!

seemed ok but can't be sure because all the work was focused on the cylinder head. the white smoke issue also happened after top set OH, implying that the mechanic COMPLETELY overlooked any problem-to-be-fixed on the block.. one of my worst pomen experiences

 

[sanekit]

awesome! good to know that you dealt with DDT before, if he solved yours then he should be able to solve mine cos the ISC is from him if really TB issue then i'll be looking to get a bigger one too!

seemed ok but can't be sure because all the work was focused on the cylinder head. the white smoke issue also happened after top set OH, implying that the mechanic COMPLETELY overlooked any problem-to-be-fixed on the block.. one of my worst pomen experiences

Franky is a very nice guy. He'll get yours sorted out. I forgot about your top set being severely damaged. I think you better go and buy 93 'kosong' head bro. Can find cheap ones around RM700 minimum. Use back your cams, valves, springs and all.

 

[drummydrew]

Franky is a very nice guy. He'll get yours sorted out. I forgot about your top set being severely damaged. I think you better go and buy 93 'kosong' head bro. Can find cheap ones around RM700 minimum. Use back your cams, valves, springs and all.

agreed! in fact i'd give him thumbs up for being very patient and helpful, good lad!

700 for a kosong head sounds like a good deal to me. my concern is that i wouldn't know if the condition of these new "used" heads are gonna be better or worse compared to mine now. hard to make thorough check with my inexperience. you know anyone/anywhere i can source it from? or should i pm you?

 

[sanekit]

agreed! in fact i'd give him thumbs up for being very patient and helpful, good lad!

700 for a kosong head sounds like a good deal to me. my concern is that i wouldn't know if the condition of these new "used" heads are gonna be better or worse compared to mine now. hard to make thorough check with my inexperience. you know anyone/anywhere i can source it from? or should i pm you?

i normally search parts on mudah and facebook groups. haha. or you can try ask this seller - http://www.mudah.my/din6a12

I saw he just upload a mivec CJ head.

 

[drummydrew]

i normally search parts on mudah and facebook groups. haha. or you can try ask this seller - http://www.mudah.my/din6a12

I saw he just upload a mivec CJ head.

i on the other hand usually ask through workshops or spare part shops. was shopping at a chop shop in klang few months ago, came across a complete 4G92 with wiring and ecu going for RM1.8K. time for another visit soon :ridinghorse:

 

[sanekit]

i on the other hand usually ask through workshops or spare part shops. was shopping at a chop shop in klang few months ago, came across a complete 4G92 with wiring and ecu going for RM1.8K. time for another visit soon :ridinghorse:

4G92 dohc or single cam? RM1.8k without gearbox ah? Damn cheap....

 

[drummydrew]

4G92 dohc or single cam? RM1.8k without gearbox ah? Damn cheap....

its a dohc, without gearbox. my father and the boss are Land Cruiser kakis, perhaps kawan price? he did joke that he could sell that engine to me as a 4G93 cos they look identical. which suddenly got me wondering on the dimensional differences between two, since both can be swapped on each other's head/block easily. you have any pointers?:hmmmm:

 

[sweelt]

I think most likely it's the TPS settings. Happens to me before. I changed ISC for my TB (mine is 93 sohc). But the idle sometimes hunting, sometimes high, and got hesitation when i accelerate. Send back to the guy (he sells stuff here ZTH id DDT), he checked my TPS was not correct and set back then all was good. But now I swap to a larger TB dy. Haha

Your cylinder walls all ok ah after what happen to your engine?

i buy tps and isc from DDT too. Nice guy. Share a lot of info.
i dont get free depo racing gauge....ya. Sincere statement.

 

[sanekit]

its a dohc, without gearbox. my father and the boss are Land Cruiser kakis, perhaps kawan price? he did joke that he could sell that engine to me as a 4G93 cos they look identical. which suddenly got me wondering on the dimensional differences between two, since both can be swapped on each other's head/block easily. you have any pointers?:hmmmm:

92 and 93 the difference is the porting and stroke. U can use 92 head on 93 block but need to port match. u can check the block for the engine number if you're unsure it's a 93 block or a 92. Mitsu mark their engine model and number on the block.

Wah. Got any nice steerings ah at that shop?

 

[drummydrew]

92 and 93 the difference is the porting and stroke. U can use 92 head on 93 block but need to port match.

Wah. Got any nice steerings ah at that shop?

ahhh so still need to do mild modification to the block to ensure fit right? i intend to retain its 93 identity if possible. its all these little details from yall fellow owners i need, can have better judgement when shopping :proud: tenkiu!

i'll be sure to keep an eye on that the next i visit! what sort are you looking for?

 

[sanekit]

ahhh so still need to do mild modification to the block to ensure fit right? i intend to retain its 93 identity if possible. its all these little details from yall fellow owners i need, can have better judgement when shopping :proud: tenkiu!

i'll be sure to keep an eye on that the next i visit! what sort are you looking for?

Eh? U can use 92 block and swap all the 93 internals in it if u can't find 93 block. 92 pistons slightly higher comp than 93. But the bore is the same. 93 got longer stroke but the the crank can fit into the 92 block. Best is to find 93 block kosong and 93 head kosong and swap. Your dad's friend can sure find 93 dohc set for cheap right?

I'm looking for MOMO 4 spoke gsr steering or Nardi 4 spoke. If can't find, I'd settle for MOMO Corse 3 spoke. It's funny when you're not looking for steerings it just pop up everywhere. When you're looking for one, u cant find any. :sleep:

 

[drummydrew]

Eh? U can use 92 block and swap all the 93 internals in it if u can't find 93 block. 92 pistons slightly higher comp than 93. But the bore is the same. 93 got longer stroke but the the crank can fit into the 92 block. Best is to find 93 block kosong and 93 head kosong and swap. Your dad's friend can sure find 93 dohc set for cheap right?

I'm looking for MOMO 4 spoke gsr steering or Nardi 4 spoke. If can't find, I'd settle for MOMO Corse 3 spoke. It's funny when you're not looking for steerings it just pop up everywhere. When you're looking for one, u cant find any. :sleep:

i see, depends on im replacing the head or block correct? good to know i asked him before but there wasn't any, the time i was there he had a shipment of R20s and K24s, some Toyota engines and only ONE mitsu 4G92.

nice taste! no promises but i'll pm you to exchange contact before going so we can communicate easier. i think these kinda things needa pray hard wan as i also need the force to help me find a 93