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Classic failed ECT?

I'd replace plugs...off-hand, it appears they have soaked up some oil, via intake valves or rings, or maybe fuel. Plugs firing via wasted spark should appear cleaner. Soaked plugs loose their full potential.

If fuel rail pressure drops, when key is switched off, this test is valid for detecting a leakie injector only if FPR and Fuel Pump Check Valve (Bosch 1587010539) are holding.
 
Gotcha, I'll pick up some fresh plugs today, ordered a bosch check valve, it'll be here hopefully Wednesday.

Rechecked fuel pressure when car turns off, in the first 30 seconds it drops from 38ish to around 23psi. Then it held for a a minute or so until I took the gauge off.

Is it supposed to hold pressure longer? Or does this seem okay?

I also cleaned the ground for the ignition module I have ran to one of the strut brace bolts. We won't know until tomorrow morning if that's the culprit or not. It did look kind of crusty and brittle.
 
Mbeas96 said:
...drops from 38ish to around 23psi....
Click to expand...

When K-Jetronic hits rest pressure of 24 psi...it had to maintain this pressure for one minute...then after twenty minutes, rest pressure should not be lower than 14 psi.

>first 30 seconds

Via testing GM vehicles, yours is dropping like a rock, so either FPR or check value issue, or leaking injector(s).

>supposed to hold pressure

The more, the better...otherwise more cranks on engine, unless pumps are activated first.

Pre LH2.4 vehicles had to crank engine before pumps would engage. LH2.4 allowed pump priming via turning key to on position. Hence, pre 1989 Volvos had to maintain fuel rail pressure....if not enough pressure, crank, crank, and crank.
 
Well, the check valve will soon be replaced. Even if it's not an issue, new is better than the unknown.

I'll recheck some things tomorrow morning, probably pull the rail and check out the injectors unfortunately.
 
RE: "... smoke coming out the exhaust with a strong gas smell...."

Looking at your build thread, I see a turbo setup...if turbo's seal is leaking oil...examine intake hose to intake manifold for signs of oil.

On semi-trucks, exhaust pipe can be smoking like a fog machine...been there, done that in 70s.
 
My turbo spits a little oil, but I had an mazdaspeed 3 that really burned oil, and this smoke was light and fuel ridden, unlike the oil smoke.

I dealt with an ect problem when I first bought this car 2 years ago, it was a PIA the 4 times I've changed it...ended up being a harness problem. Hopefully it's not my wiring that's the issue. No codes are showing either, which leads me to believe not ect, but something mechanical.

I have time tomorrow. I have some transmission cooler lines to change as well, so since I'm going in, might as well go deep. I'll swap the ECT and see what happens.

Car ran great all day after I started it this morning, no strong fuel smell and no misfiring. Good gas mileage. Pulled hard at 9 psi at WOT. I don't understand.
 
I've thought that, so I end up opening the throttle at least partially while starting.

I'm terrible with multimeter. And need to pick up a decent one to learn how to use it effectively...but until then I replaced the ECT with a "known good" off a parts car.

I also repositioned the ignition model ground to the inner fender behind the turn lamp. Should be better than the strut brace.

We will see tmorrow morning.
 
Replacing ECT made zero difference. Extra cold this morning (40?, lol) and I cranked till the battery died. Set up the jumper cables, let it sit for 10ish minutes, hoping the extra fuel evaporates off...and it fired right up.

In total took about an hour to start the car. Drove fine and no extra gas smell.

Next step; clean battery main ground, pull rail and see injector's fire cold, and then I guess check valve. Just started first try on my break.

Some reading on the check valve only seems like it would delay starting for a few cranks. Not 50...

I'm leaning towards spark issue. Forgot to mention I tried a couple long sprays of brake cleaner with the injevtors unplugged to no avail...tried to fire but would not stay running.
 
Buy some John Deere 80% Premium Ether Starting Fluid - RE556468, and inject into intake port when cold start issue happens.

>pull rail and see injector's fire cold,

Manually, fire up fuel pumps at fuse first....with ignition OFF
 
I'll have to check it out.

Pulling the rail will have to wait till the weekend unfortunately...

I can try putting a jumper wire in place of the relay?
 
Go to leave work at 5pm yesterday and car won't start. Not trying to wait around to see when it'll start I immediately hook up some jumper cables to a buddy's car. No dice. Swapped in spare coil pack. Nope. Swapped ignition modules, nothing. Tried real starting fluid with injectors unplugged, will not start.

After 45 minutes with a few 5 minute breaks, also a couple times dry firing to try and burn off any extra gas. It finally starts and I drive home like nothing happened.

I have a spare AMM, not a spare cps, I'd be suprised if that's the issue though...mines not quite a year old and my tach bounces when starting.
 
Mbeas96 said:
Go to leave work at 5pm yesterday and car won't start. Not trying to wait around to see when it'll start I immediately hook up some jumper cables to a buddy's car. No dice. Swapped in spare coil pack. Nope. Swapped ignition modules, nothing. Tried real starting fluid with injectors unplugged, will not start.

After 45 minutes with a few 5 minute breaks, also a couple times dry firing to try and burn off any extra gas. It finally starts and I drive home like nothing happened.

I have a spare AMM, not a spare cps, I'd be suprised if that's the issue though...mines not quite a year old and my tach bounces when starting.
Click to expand...

I wouldn't be at all surprised if the CPS is the problem. I have had several 2-7-9s that had spark, fuel and good compression and wouldn't start and it turned out to be the CPS. I have learned to recognize the behavior. The first one I spent 10-30 minutes each session over a period of a week working on it and finally came to the conclusion it had everything it needed to run, yet wouldn't and threw another CPS in it. The 240 fired right up and ran perfect. The previous owner had spent $1,200 at various Volvo shops trying to solve the exact issue you are dealing with. They finally gave up and put it up for sale on craigslist. When I went to look at it, they went in for dinner and said "Let us know what you decide". It fired right up and I loaded it on the trailer. They came back out when I just finished chaining it down. They were surprised it started for me. Then, they elaborated on how it does that, runs perfect, then, strands them. I brought it home, unloaded it and didn't get back to it for a few days. It would not start, period. I could try until the battery was dead from cranking and nothing.
 
I had similar symptoms with my first 940 and it was the cps.Now I replace the cps as part of my stage zero on any new to me 7/9 car.
 
Looks like I'll have to track one down. My hopes are high. Car would not start this morning, had to take my jeep. Toward the bether half of an hour and a half I feel like I've ruined my oil and probably soaked the plugs in gas to the point where it wouldn't even try to fire.

Also I swapped AMM's this morning with no change, made sure to get gas before parking, so it had a full tank.

Will report back
 
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84B23F said:
If injector(s) are not pissing away, then one might consider a defective CPS

Nice video on AMM/CPS: https://www.youtube.com/watch?v=l4l25NfTyl8
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I have given up on recommending the use of a scope here on tbricks.

Mbeas96 said:
I'm terrible with multimeter. And need to pick up a decent one to learn how to use it effectively...but until then I replaced the ECT with a "known good" off a parts car.
Click to expand...

Start with a test lamp. Get a meter too. $3-5 each at Harbor Freight.
 
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ZVOLV said:
I have given up on recommending the use of a scope here on tbricks.



Start with a test lamp. Get a meter too. $3-5 each at Harbor Freight.
Click to expand...

Yeah...I've had problems in the past a oscilloscope could of solved, maybe I should quit being ignorant to the stuff that'll help tremendously...I'll look into a lamp and meter as well...
 
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