I’m resurrecting a ‘92 Lebaron GTC hardtop, 2.5 T1 with A568 manual and needing some help. This is my first Mopar and being a newbie there’s a lot I don’t know about these turbo 4 cylinders. I’m familiar with boosted cars in general, but only with GM vehicles so this is a bit different. No flames please – being a GM engineer for 18 years you buy what you design and work on what you know, and having access to all the factory service manuals and tools keeps one from straying too far. So I’m really in the dark on this Lebaron although I’ve surfed Allpar and the 3 big turbo Mopar/Dodge forums for research so far so I’m getting there.

My only real disappointment with all my blown GM cars is that they’re all automatics, and I really missed driving a stick, so this Lebaron should be fun, and the fuel economy of the 4 cylinder is a plus these days. But, it’s got to be the slowest turbo J car ever known to man! This brings up my first couple of questions – where are the timing marks, and how do you change the timing belt tensioner and set the cam timing? I’ve searched the forums for this basic knowledge but haven’t found anything – I think my questions are just too basic.

Initially after I got the car running, the turbo was frozen stuck – wouldn’t turn at all, just a huge exhaust and intake blockage. This was originally why it was truly the slowest turbo Lebaron (might as well just say slowest Mopar) ever known to man. It was like driving with a throttle stop at 20% throttle. It’s a good thing Indiana is totally flat – she wouldn’t run over 50 mph in 4th (2500 rpm) – just flat ran out of air. Putting her in 5th and dropping the rpm to 2000 helped a bit – now she had just a bit more headroom before maxing out the airflow and she could eventually hit about 60 mph.

I drove it to work the next day and after lunch forgot that it literally would barely get out of it's own way and pulled out into traffic on US 31. With a semi barreling down on me I kept her in 1st at WOT and prayed she would pull past 3000 rpm. Well, apparently with repeated temp cycling, exhaust heat and oiling, at about 3500 rpm the turbo broke free! I hadn't hooked up all the wastegate and BOV lines since the turbo was frozen, so she pegged the stock 15 psi boost gauge real quick, but the engine didn't ping (with 87 octane gas) and honestly even at 15 psi the power wasn't impressive at all. I did manage to stay ahead of the semi so that was enough.

So the little Mitsubishi turbo is free and spinning now, but after studying the hose diagram under the hood and hooking that plumbing nightmare up with all the T's and check valves, I’m only getting about 5 psi boost and it’s still a dog. I have to say (no flames please), that the plumbing on my turbo Buicks is much simpler! I've seen conflicting posts, but I've read somewhere that this '92 SBEC-II ECM (which I understand may be really rare - thus probably hard to find any programming for unfortunately) does limit boost to 5 psi.

I figured if it didn't ping at 15 psi and 87 octane, the timing must be way retarded, so I’ve advanced the ignition timing a bit and it’s better, but the lower end is still soggy and in no way will it even chirp the tires. The throttle response is much better than before - it doesn't lay down after each shift now, but I still don't think it's where it should be even at 5 psi. Now it’s idling at between 1200 and 1400 so I’m sure the timing is advanced too high, although I don’t understand why the idle air control circuit can’t compensate and bring the idle down. I would think I have a leak and it’s getting excessive air, but the vacuum is good (15 psi or more) and I don’t hear a leak.

One of the things I don’t know is how to actually check the timing. I’ve a friend at work here that’s a Mopar guy currently heavy into the Mitsubishi 3.0L on the TD forums. He’s pointed out that the timing indicator is on the flywheel. I’ve found a small window (had a piece of foam plugged in the hole) in the bellhousing and see the flywheel teeth through it, but I see no markings or a scale. Looking at the flywheel through the timing light, I think I see a timing mark on the flywheel but it’s jumping around – I assume because it’s under ECM control. I was told to unplug the coolant temp sensor to make the ECM go to base timing, but I can’t find the sensor for the ECM (found the one to the dash). So where’s the scale to line the flywheel timing mark up against? It should be at 12 deg BTDC, but I don't know where to line up the marks to read it.

The timing belt tensioner is making quite a bit of racket, and we thought maybe the cam timing is retarded, giving me poor bottom end, so I thought I’d check this when I changed the tensioner. Any hints on changing the tensioner or setting the cam timing?

I’ve got lots more questions, but this post is way too long already. I’ll ask more later! Thanks for any help y’all can give on these 2 immediate issues.