Situation: I go to start my car this morning and it cranks fine and starts but sounds like it's about to quit. There are no unusual noises when cranking or when the engine is running, it just sounds like it's being starved of fuel or possibly is not timed correctly? (Already had the fuel filter changed recently and both fuel pumps are running normally) It shakes like it's going to jump out of the engine bay when it is running. It will run for a few minutes like this and then finally it just stops acting up and idles like it always has. As far as I know, all the injectors are working. I just replaced the plugs recently as well. I did have a chance to pull the MAF lead but that lead to a no-start.

It started the previous day and drove 100 miles with no problem. I haven't had a chance to check anything in detail yet but wanted to get those gears turning.

Could it be a timing issue? It has showed no symptoms like this until now. Possibly an electrical problem?

Will update after I check it out in the morning.

Thanks for any help.

 

Your car has LH2.4 fuel injection and the EZK116 ignition. It times the car, no real adjustment there. Sure the cam belt can jump time, but that doesn't fix itself as it warms up. The first thing to do is pull any codes from the OBD. Being a turbo, they are HORRIBLE on vac hoses. Underhood temps are higher and the vac lines carry not only negative pressure but positive pressure as well when in boost. At first glance, I would say to look at the IAC connections and especially the hoses leading to it. The IAC can be thought of as a choke and adjusts the air flow depending on the temp of the motor. If there are no obvious issues there, I would look into the TPS (throttle position switch) to make certain it is adjusted properly. The ECS (engine coolant sensor) reports to the ecu as well with the engine temp. Depending on which end of the spectrum it fails, the car will either hard start cold and warm start fine or cold start fine and flood when engine is warm. Check the codes first.

 

Well I had a chance to do some checking.
I pulled the following codes:
Module A pin 2 --> 1-2-1
Pin 3 --> 1-2-5
Pin 6 --> 1-1-1 (all clear)
Module B pin 3 --> 1-2-2 (no idea what module B is for)

I also pulled the throttle body and cleaned it thoroughly, it was totally crud on one side. I also made sure the two holes for the vacuum hoses on top were clear. The TPS is adjusted properly. The IAC is right below the throttle body that looks like a horizontal soda can with three hoses coming off of it right? If so, that is in good condition. I had already replaced as many vacuum hoses I can get to very recently such as the two that connect between the top of the TB and that (charcoal?) canister. The two hoses on the turbo (CBV and wastegate actuator) and the hose that leads from the intake pipe to the PCV system.

After I cleaned and reinstalled the TB, I took the car for a spin around the neighborhood. It seemed like a lot of whitish exhaust gases were coming out, more than usual. After a while of driving around it cleared up and no more visible gases were seen. Why is that? Was it just burning off some residual "stuff"?

Also, since the engine is supposed to be running under negative pressure when it's not in boost (obviously), if I take the oil fill cap off while the engine is running, should there be any visible gases coming out? Or should there be some kind of negative pressure or suction keeping gases in and circulating through the PCV? I should probably have the PCV system cleaned because I don't think that it has been in its entire life (apprx. 189,000mi).

As for the ECS, I have two sensors under the intake. They are almost right next to each other. One is higher(closer to the intake manifold) than the other one right under runner 2 or 3. How is the numbering of the runners determined? Front of engine bay to back or vice versa. Or does it just go by firing order?

thanks for any thoughts or advice.

 

Hmmm...1-2-1 is the AMM. Check the connector pins for corrosion or bent pins. They're very tiny and easily bent. Clean it out while you're there...MAF cleaner is the best but carb cleaner is cheaper and almost as good. I always do away with the upstream screen as it's worthless. Spray some carb cleaner on a Q-Tip and GENTLY wipe the wire off. Then hose it with a couple of blasts of spray. I have no idea what socket #3 measures. Socket #5 on some turbos monitors the turbo system. Module B monitors ABS if I recall correctly.
I will share something I learned about 20+ year old turbo Volvos. When I get my hands on one, I ALL the vac hoses without even looking at them. I spent several hours over the course of a month trying to track down a little miss under moderate throttle. Replaced some suspect hoses...no change. I finally bought some silicone hose in bulk and replaced all of them. Afterwards, I examined all the old hoses. One had a split that only opened under minor boost. Under full boost, the engine generated enough pressure it didn't matter...The split would never be seen with the engine off as it was closed. So..now, I swap them out as a matter of course; it just isn't worth my time at my age to track something so easy to fix. I am no advocate of throwing parts at an issue but vac hoses are often overlooked as sources of annoyance.
Intake and exhaust runners, as well as cylinders and plugs, are counted from the front of the engine going back towards the firewall. The first sensor you see, near runner #2, is the temp gauge sensor and has nothing to do with the injection system. The ECS is located by #3 runner and has a 2 wire plug whereas the temp gauge sender has one. If you go south, you will see the knock sensor mounted to the block.
I took a picture just now of my motor...it's a 94 turbo motor so identical to yours...The yellow cicled sender is the knock sensor. The black circled sensor on the left is the gauge sender while the one on the right is the ect...

 

Well, I check the amm connections and they were clean and still had ample electric grease on them neither were they bent. I sprayed out the amm, reinstalled and cleared the codes. 1-2-1 no longer present. Great, but that did not solve the problem. I disconnected the IAC totally and it's hoses and checked them out. They appear to be in good health. With the IAC out of the way I pulled the oil separator box and cleaned that as well. Reinstalled those but the engine still has that horrible rough, shaking start.

So, all the codes are gone except for the 1-2-2 on module B which I could not clear for some reason.

This leaves the ECS you mentioned. Would you happen to know what the correct voltage is I should be reading from it? Or even if it's resistance I should be checking?

*funny, the temp sensor for the dash that has one wire on your engine is not so for mine, both of the sensors have two wires and what looks like a D shape connector. The one under runner #2 is connected straight onto the sensor, while the other looks like it is connected at an angle.

Thanks again for the pointers and troubleshooting help.

 

Just an update to my current situation.

While trying to diagnose my hard start It became clear that my thermostat was stuck closed... Great, one more thing to fix, so I replaced that and no more worries of overheating.

Back to the real problem. My distributor cap and rotor were in need of replacement so I replaced those along with the plug wires. Hopefully those were the source of my hard start. Start it up and the engine stumbles for a few seconds then clears up and runs smooth as butter. I let it idle for a while just to make sure everything was running the way it should. I take a spin around the neighborhood and when I get back in my driveway (after putting the car in park), it starts to do that horrible shaking again. I took it for another quick spin just to see if it would go away. The car will still shake while accelerating until the car is moving like normal driving around the neighborhood speed and the shake will go away, UNTIL I come to a stop again at, say, an intersection. The engine will start to shake again until I accelerate and bring it up to speed. Why is this? I checked for codes repeatedly but everything is showing 1-1-1.

I can start the engine and let it idle forever. It will idle smooth as butter and won't start shaking until AFTER I drive it around, in which case it won't stop until I am either driving or turn the car off and let it sit for a while.

By the way, I did buy some silicone hose and replaced the vacuum hoses as well.

I just don't understand what could be causing this and am at a loss of what to look into next.