1G 90 dsm ips and idle problem

[1990dsmkid]

Alright I just replaced my throttle body shaft seals and reinstalled e erything. I did blt and found 2 small leaks and fixed them. I did set my tps volts to .48-.52 according to fsm. The isc coils all read 29.7 ohms and I did remove it and had someone turn key to on position. It spun and moved so Im pretty sure its good. I then went ahead and started the car and let it run to get to operating temp so I could adjust biss if need be. Well once it started getting close to operating temp it started to surge ever so slightly and would get a little rough sounding then it shut off. I figured I would go ahead and try adjusting my ips. Well Im following the fsm and I cant get the resistance to read without jumping around so I added a ground wire along with grounding strap. Still had same problem so I grabbed a test light and clamped it on the ips and held prone on postive terminal. I spun the isp until the light came on then turned it another 15/16 of a turn. Will this work correctly in setting the ips? Tomorrow im going to try another blt and letting the car idle to temp. I just went this thing to idle correctly

 

[AllanL]

the IPS is set first, even before the TPS.

tighten it until the point of continuity, and then 15/16 turns more. tighten the 14mm lock nut holding the IPS.

then set the TPS to 0.48~0.52V.

 

[1990dsmkid]

Im going to double check everything again tomorrow but if I follow the fsm way to set ips I cant get a good solid reading. The number just jumps all around. I cant see it being a grouding issues. I have the stock ground strap plus I added another wire to ground. Like I stated, I used a test light to find continuity which I hope works correctly and turned it the 15/16 n locked it down. Im hoping after double checking it all it will idle and warm up so I can adjust biss accordingly. My main concern though is why wont my multimeter read a steady constant ohm reading on ips?

 

[AllanL]

it shouldn't read any ohm reading anyway. it is either open [zero Ohm] or shorted/continuous [infinite Ohm/full needle sweep].

i'd remove that IPS from the throttle body, carefully remove the rubber boot covering the plunger, and give it a spray or two of contact cleaner, while turning the switch on and off [rod/plunger in and out]

the rubber boot is the one below the arrow in the image below...

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[1990dsmkid]

Whats the easiest way to remove the seal?

So with throttle closed I should get infinite ohms and with open I should get nothing? If so then I should have it set correctly or close to it. Im starting to wish I never touched it

 

[AllanL]

it is not stuck to anything. it is not a gasket.

it is just like the dust boot for your axles.

i'll edit my previous post: seal --> boot

 

[AllanL]

So with throttle closed I should get infinite ohms and with open I should get nothing?

correct!

and never give up!

 

[1990dsmkid]

Ok thanks. Ill go over everything again tomorrow. Now if I used my test light then it should be on with throttle closed and turn off as soon as i start to open it. Just clarifying

I really hate anything electrical related.

 

[AllanL]

correct again!

you should also feel the throttle plate opening smoother when you reach the sweet spot...

 

[1990dsmkid]

Ok thanks a lot. Hopefully I get it idling correctly

 

[1990dsmkid]

Got it idling correctly! AllanL you was right. I rechecked the ips then rechecked the tps. Tps was way off from what I had it at yesterday before I messed with ips. Got it all in spec and now the car idles as it should. I appreciate your help

 

[AllanL]

good to hear!

 

[1990dsmkid]

Well I might need to adjust idle just a bit more. After driving it some it seems to like to get around 600 rpms at stops n go back up to 750ish and its a little rough but might be something else. Ill get it figured out though. Just glad its idling, running and not surging like it was.

 

[AllanL]

Have you confirmed that base timing is at 5deg BTDC with the timing adjustment terminal grounded?

 

[1990dsmkid]

No I havent yet. Its on the to do list.

 

[1990dsmkid]

I adjusted the timing to 5 degrees btdc. Car is still having a weird idle issue. Im going to recheck tps this week and mybe adjust the biss a little. Also do a blt. This idle drives me nuts. One minute it idles fine then next its idling to high or to low or has a little surge. Im still thinking its isc related

 

[thakingcb7]

Sounds like the same situation I'm in. Mine surges when cold, stalls, surges again, and then smooths out when warm. Also does this crazy thing where it'll hold idle between 1500 and 2000 when I drive it on the highway until I stomp the throttle quick or let it come down on its own. I thought I got rid of my idle issues when I sold my honda.

 

[1990dsmkid]

Yea its getting annoying. Hoping to check over things tomorrow

 

[thakingcb7]

I'm too lazy to do anything about it right now. I've been trying to build a BLT but every time I get in the mood to do something I find other more fun things to do.

 

[1990dsmkid]

I hear ya on the lazy part

 

[inthemidst]

Remove throttle body point it at the sun if you can see light adjust the screw until u get the minimal light tighten the nut and make sure their is no binding when u throttle it. If u still have problems with an idle start looking into the ecu.

 

[1990dsmkid]

My throttle body is rebuilt and I checked everything over. I just need the time to blt, check my tps again, and check the isc again. Im almost 100% sure its my isc. I have a tan 91+ isc that I need to check out and extend plug wires if its good.

 

[acrazyjohnny]

might want to make sure the throttle body has a good ground.usually they get corroded or just dirty. check the pic for the ground strap for 90 tb

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[1990dsmkid]

I have the ground strap and I even added another ground just to be sure.

 

[1990dsmkid]

Well I did a blt and found no leaks. Ips and tps are set correctly. Still having bad idle issues. I was letting it warm up and it died on me twice. I pulled the isc out and had my brother turn key on and off. It moves and makes sounds. Not sure if its moving enough or not. Ohms out fine. I need to make a pigtail adapter so I can try the 2 91+ iscs I have. I still believe its isc or ecu related. I need to find someone with a good 90 ecu or find someone with a stock 90 eprom chip. Hopefully one of those fixes my issues.