xrav22

Don't forget to make sure your TpS sensor is good that can affect idle, I think you have an auto adjust every start but even if you don't set it the pot can go bad and give erratic readings to computer, even
if you don't have to set it to .54

eutu1984

I did check it,on the 90 its non adjustable so it cant be adjusted, I replaced it about a year ago, right now the car will not even run, I replaced the pick up coil, unplugged the est wire and set timing, shut the car off plugged the est wire back in and now she will not run. I am going to take a break till this weekend and work on it then.

eutu1984

Ok she is up and running, my ignition module died on me, unfortunately I still have a rough idle. It seems worse when the hotter she gets. I am going to take another break from it now, I did do a short data log at idle I will post it when I get a chance.

eutu1984

here is a data log I ran wile idling.

https://drive.google.com/file/d/0B5d...ew?usp=sharing

tequilaboy

Check your fuel trims with a scan tool while running in closed loop. Bosch IIIs are often reported to run leaner than their flow rating.

eutu1984

I am new to data logging, by fuel trim what do you mean, I have aldldroid and it does not show fuel trim, it does show blm, int,bpw,blc,

at idle blm's stay at around 128, I know if it reads higher it is compensating for a lean mixture and lower is a rich mixture.

tequilaboy

The idle appears to be steady based on the posted log. Roughness is not apparent in the data. Idle appears to be tracking target rpm +/- 25 rpm around 20 IAC counts. Fuel trims (BLM and INT are on the money).

I don't understand the complaint.

eutu1984

Its very rough at idle, especially in gear even though the data looks good, it vibrates so bad in gear the vent cover almost pops off, it also vibrates in natural just not as bad.

xrav22

If I had your car, I would check and clean all the connectors and put some dielectric grease on them, put a timing light on all spark plug lines to make sure they are all firing, and then try simply adjust the distributor slightly each way and test drive , old school way. I have a slight cam feeling but it doesn't make too much vibration.
Good luck

I had to use d grease because the corrosion in the connectors would keep coming back if I did not.

eutu1984

I did everything you mentioned already before you posted, I decided to run some Lucas gas treatment through it and it seemed to improve very slightly last weekend, It sat al week and when I started it it did not fire as fast as it normally does, and does not seem to be accelerating as smoothly, the injectors ohm at 15 cold 18 hot so there is no problem with the windings in the injectors so im starting to lean towards clogged fuel injectors or junk in my trunk (gas tank). When I have a chance I will pull the fuel filter. For now I think I will at least drive through a full tank of gas and see what happens.

aklim

Ohm test only tells you that your coils are ok. The only way to truly know is to put them on a test bench and see if they spray pattern and volume are good. If the filter basket is clogged and you are only getting no volume, the ohm test will say it is good. I would take them out and have them cleaned and tested at FIC.

Take the filter out and replace it if you haven't already. I think you can take the sock in the tank out but I wouldn't without ordering a new gasket and sock.

All that Lucas thing will do is lighten your wallet for sure. It may clean something but you don't know how much. Try cleaning a room blindfolded. Sure, you did clean something but how much is left, you don't know. I test it every 3 years. I read the "before and after" and I can see that some crud has built up or the basket filter might be dirty.

aklim

Why fool around with the distributor? I would check spark quality in a dark garage to see if you get a blue flame or not. Also make SURE and check again for the firing order. If the timing is on 6 with EST disconnected, that is where you want it.

eutu1984

Already done.

Solderhead

Hello. I think I need a bit of clarification here. Does the engine idle fine in neutral?
What are the symptoms of your rough idle? Erratic misfires? does the engine speed surge and drop on its own? Any discoloration in the exhaust? Strange smells? Does the engine run properly when you're giving it throttle?

aklim

I have an inductive timing light that can check rpm based off spark signal. Can you use something like that to see whether each wire is getting about the same rpm based off signal in the wire?

You said you have good spark, correct firing order so maybe the fuel injectors are problematic? Is the fuel pressure correct throughout or just at idle?

eutu1984

Engine idles rough in neutral, and worse in drive, it does sound like slight mis but no misfires, rpms are pretty steady, this morning I went to start it it almost would not start and now its running rough going down the road.

eutu1984

I have the inductive timing light and already did the check you sugest, last time I did the fuel pressure check I just did it at idle and it checked out good, this morning I removed the fuel filter and cut it open and it was very clean inside and its been on there about 3+ years, I will hook up the fuel pressure gage and tape to the window and take it for a quick run.

eutu1984

Ok just came back from fuel pressure check, at idle 34, with vacuum line removed from regulator its 44, going down the road it holds around 34 untill I get on the gas then fuel pressure increases to the low 40's. With engine off the fuel pressure holds.

antfarmer2

I thought it was to go up with the vacumme line off

eutu1984

It did go up it went from 34 to 44.