Been having the title subject issues for a little while.
Starting from a light, the car stutters when hot, 4th gear floored at 2k RPM stutters to 3K RPM then pulls hard to RL. 5TH same.
Hard starts when hot. Cranks normal speed, but just doesn't start with 30 seconds of cranking. Second time cranks for 20+ seconds before stumbling to a start. Take off from start, stumbles until above 2K RPM. Stumbles at 2K-3k under hard acceleration.
I changed out the water temp sensor.
Turns out my 95 takes a 94 temp sensor. I did that because of a code and it hasn't come back.
I re-checked timing, that is on point.
Idle is steady at 750-800. Idles up with AC to 1150-1200.
I prefer a little higher idle since I have E fans. Mech fan removed.
Performed a fuel pressure and leak down check. All good there; solid pressure before and after start, solid after shut down. Vacuum test was good. Steady needle when idling.

Checked primary coil resistance= 1.2 Ohms, Secondary was 9.7K Ohms at first, but immediately went to 16K Ohms and stayed there.
I measured it from the primary to the contact tower going to the distributor cap.

The question I have is: Is this secondary coil resistance excessively high?
Seems to me that the primary is on point. It's just the secondary is in question.
And would a dizzy re-stab be in order at this point. That is questionable.

Checks in spec. Primary is .7-1 Ohms, so with meter error, that should be in spec, and secondary is 6K-30K Ohms. Sounds like the coil is all right. No ECU codes at all?

Nope. No codes. I had the scanner on it while running. O2, MAF, and TPS all seem to be functioning normally. Replaced knock sensor and eng temp sensor. No change.

Hm, MAF was going to be my next suggestion. Let me see if I can get a bit more of a 240 guru in here to help.

Only other thing I can think of is a vacuum leak. Sounds a lot like how my old Subaru would do. Turns out the upper plenum bolts were hand tight. Tightened them down, put a spot of torque seal on it, and it ran fine till I sold it. Possibly try taking some brake cleaner and spraying it around in the bay while idling and see if the idle changes at all. If so, you've got a leak.

I'm guessing since he did a vacuum test, he doesn't have leaks.

Did you replace the temp sensor with a new one?
Since you had a scanner running, I'd guess you could confirm that the temp sensor works, even if it was a used one.
My car used to be very hard to start when it was hot, and it turned out the water temp sensor had died.

When did this issue start to occur?

Have you pulled a plug and actually looked at it/checked spark strength?
It could be the result of some dirty contacts/worn distributor cap/rotor/water int he dizzy cap.

Also, you could have a post-MAF leak that would seriously mess with your Air/fuel ratio, but wouldn't show up on a vacuum check.

I re-checked and adjusted TPS down to .5V (middle ground), reset idle stop screw, re-re-adjusted TPS down to .5V. Re-checked timing with TPS disconnected. No joy up to this point.
Pulled all spark plugs and blocked TB open to do compression check. All pistons above 200PSI !!. I must have some serious carbon deposits.
Anyone seen this before??
Revs without load seem to be better after the aforesaid adjustments, but there is still a stutter if I stab the accelerator. DETONATION?!??!

I did find a clamp loose after the maf. I have a short ram to the left. Battery moved to the right. E fans.
Checked IAT sensor. Looks good. Responds to my touch(that's my girl). Not lazy. Re-re-re-checked everything again after that.

The high compression numbers trouble me. I see others happy with 170. Not sure what this means. My motor has almost 190K miles and I have never done timing chain since purchase at 60K miles. Am I f-ing up?

No, I haven't checked spark with the plugs out of the engine. I'm more concerned with the high compression and the slow cranking without the plugs in.

Check your valve timing. That's super high.

at TDC (either compression stroke on #1 or #4 cylinder), your cams should be somewhere between 9 and 10 o clock on the intake, and 2 and 3 o clock on the exhaust. One cylinder (either #1 or #4) should have the cams in that position.

I will be doing that tomorrow. Hopefully I can verify the alignment on the upper chain and not have to get into the lower end. I've only been under the valve and timing covers once to change the main seal and check valve clearances. I wasn't a 100% confident about the cam timing the last time I had eyes on it; but i have put 130,000 miles on total since I bought it. Prolly, 30,000 miles since the last time I was under the valve cover. Yes, before it's asked, the engine was disturbed and I aligned everything on the marks. What I'm not sure of is if I had tension on the left side of the lower chain and upper chain. Curious why this seems to have caused so much trouble "overnight".

I re-checked compression with the O2 sensor out. Thought I might eliminate a clogged cat. Numbers went down , but only to 200.
Considering unbolting the exhaust manifold to totally eliminate the cat. God I hope that's it. I don't want to do cams, unless it's a last resort.
Oh, and while I did that compression check, there was a pronounced (audible) tap when I started cranking, but just one. Does that sound like a Catalytic converter substrate gone rogue?

A bad/plugged cat won't usually show up until higher revs/air flows. The 200psi compression is odd. Either HEAVY carbon deposits, cam timing off, or your gauge doesn't read correctly.

How is it cold? Is everything OK? If so, I suspect a bad CAS. I've never had one throw a code, but I've had 3 of them give hard to diagnose and irratic running problems. The only way I was ever able to diagnose them was after trying everything else to try swapping it with a known good one and the issues followed the CAS. Is there a local with a KA running properly that you could swap with to confirm?

Cam timing was off. I only have one link that is marked Gold. no other paint marks. the idler pulley position didn't make sense either. It was pretty much 180 degrees. the FSM points between 160 and 170 me thinks. first try after adjustment didn't start. re-stabbed dizzy and started right up. didn't go past idle. I have to let the sealant set.
I'm going to have a shop do the whole timing chain replacement. I don't trust the chain set I have, because it doesn't have marks to verify alignment. Whack. Hope my instincts are right. I have to drive this to work in the morning.

got a 340 code (CPS). when I finally started the car. Speculate that is because I was cranking the motor without the dizzy installed. Cleared code and didn't come back while idling.

Yea, that's from the removed dizzy.

Nice. I was going to say, you could just snap a pic and post it here. We could tell you if the cams are right.

Eventual resolution: I gave up and took the car,(while it was still running) to the mechanic. They replaced my clutch and flywheel, pulled the motor and did the chains. Problem was, when I got it back, the hard start when hot was still there. I pulled the plugs, valve cover and upper timing cover, pulled the upper cam gears and chain, loosened all the caps for the cams, rolled the motor until the timing marks on the idler pulley matched. Matched the cam positions (approximately), installed the caps, top chain (matching all marks). Loosely tightened the cam gear bolts and rolled the motor through a couple revolutions. Put the front timing cover on the heater (it's freezing here). Buttoned up, stabbed dizzy, crossed fingers and wdyk? It started right up. Idles great timing spot on. Now I have the confidence to do a cam swap.

I want to ask the mechanic for a partial refund for the hours I spent fixing what I told them was wrong and they didn't fix. As soon as I got the car home, I did a compression test. It was 125 across all four cylinders. Took me two full days to figure out the process to get it done without pulling the crank pulley and lower cover. At least they got the lower chain right. The clutch chatters like a caffeinated chipmunk. Between the rough idle and new clutch, I couldn't get out of the mechanic's steep driveway. I should have done it all myself in the first place. With patience and persistence, I got it right without damaging anything. It would have saved me $850.00. The car is barely worth that much.

I don't know whether to congratulate you or pity you haha.

PapaSmurf2k3 wrote:I don't know whether to congratulate you or pity you haha.

I seem to have a penchant for breaking stuff more before I fix it. Not a good quality in a mechanic. Then again the mechanic did that too!