98 V70xc Starts then immediately dies

New2Volvo98 · Post by **New2Volvo98** » 05 Dec 2020, 15:08

Hello all,
I know this topic has been discussed on other threads but I have yet to find an answer to the problem I am having. Hope someone on here can help me out. I bought a 98 v70 xc with 184,000 miles. I especially liked this one because it was a Cannondale edition which I thought was pretty cool. The car ran and drove ok but the started was going out and it sounds like a small exhaust leak somewhere. The previous owner didn't really have any maintenance records so I decided to replace the spark plugs, plug wires, distributor cap, oil cap gasket (leaking oil) and the PVC because I wasn't sure if it had been done before. After I got everything put back together I went to start the car and it ran for about a second and then died. It did this over and over. When it runs for the few seconds it has a really rich gas smell. I have checked the fuel pump relay and jumped it and have pressure coming from the fuel rail so I don't think it's that. I made sure all hoses, plugs and vacuum lines were plugged back in. I took off the antenna ring and sprayed electronic cleaner on the pins, I thought maybe could be a the MAF sensor. I had cleaned it when I first got the car. I unplugged the MAF and started the car and it actually stayed running but ran TERRIBLE. It was puffing out white smoke and smelt terrible of gas. Could a bad MAF cause all this. I have read that typically if your MAF has gone bad you can run the car without it plugged in and it will run better. Any help is appreciated because I am kind of at a loss here. The only thing else I can think of is maybe a cam sensor but I don't want to keep throwing money and parts at it hoping to fix it. Thanks!

Post by **abscate** » 05 Dec 2020, 15:14

On any turbo car an induction leak will make for rough running, especially at idle. You can’t visually inspect these , you have to remove each piece, inspect, and reinstall carefully, replacing any bad clamps or rubber. This is 10x more likely than a failed sensor or part swap problem

New2Volvo98 · Post by **New2Volvo98** » 05 Dec 2020, 20:07

I thought about that but I assumed I put it all back properly but i will check all the intake hoses and clamps just to make sure. Thanks for your feedback.

Post by **abscate** » 06 Dec 2020, 02:58

It’s easy to get the spark plug wire order wrong, triple check that. The Haynes manual even gives the wrong firing order in some manual versions.

At some point diagnostic equipment is needed, compression test for motor, fuel pressure gauge for the fuel delivery

hipcheck · Post by **hipcheck** » 07 Dec 2020, 18:33

Take a picture of your intake manifold just left of your throttle body. Post it here.

I had the VERY same problem you described

This was the problem:

The PCV retaining clip was between the intake manifold and the engine block. Huge vacuum leak. Here is a screen shot from the FCP video I followed while I did my PCV and the moment in the video where I realized my clip was in the wrong spot!

I hope this is all that is wrong with your car.

Post by **erikv11** » 07 Dec 2020, 19:30

+1 to hipcheck's comment. Check that.

hb00 · Post by **hb00** » 15 Feb 2022, 15:24

I have 2000 volvo v70 xc. Starts then dies immediately. 160k miles.
New xemodex ETM installed, new fuel pump relay,

After jumping fuel pump relay to diagnose, it stayed running.
So i installed new fuel pump relay. Ran smooth then rpms started to fluctuate after idling for several minutes.
So I took it for a test drive. Ran very erratic. If I stomped on the gas it would accelerate with great power, otherwise it wanted to loose rpms or run very ruff. Topped off gas tank (only needed few gallons) drove back home.
Shut car off. Car would re-start then die immediately.

I run a jumper wire to the ETM. Car starts and idles fine, thought i found problem again. idles for several minutes, then rpms begin to fluctuate and then dies.
I have replaced immobilizer ring, crankshaft sensor, camshaft sensor. new battery.
Fuel pressure at the rail is 58psi while cranking. Fuel pressure falls to around 30psi with key off.
Now car cranks and will not even start.

Im sure I'm missing something.

Any help out there?

Post by **scot850** » 15 Feb 2022, 19:08

Is the Xemodex unit actually a 'new' unit or your own one repaired? If it is a replacement unit was it programmed to your car?

58psi is what the fuel pressure should be while cranking.

How quickly does the fuel pressure drop off?

This could be a failing fuel pump that starts the car but overheats as the car warms up.

When you replaced the fuel pump relay, what brand is it?

Have you checked all the pipes you removed and wires/connectors have been refitted?

Were you having any other issues prior to the new Xemodex unit which led to it being replaced/repaired?

Neil.

hb00 · Post by **hb00** » 16 Feb 2022, 06:45

Thank you for the reply Neil,

Yes, New programmed Xemodex unit. Did seem to run worse after replacing though.

Fuel pressure drops to 30 PSI after 15min

Car will not idle at this time even with fuel pump relay jumped and Fuel PSI at 58PSI.

Car fires then dies immediately

I was able to keep it running barely by attempting to rev with gas pedal. But now no luck with that either

I have checked all pipes and connectors. But I could of missed something, I will keep looking.

Yes previous to replacing Xemodex unit, car would occasionally loose power and go into limp mode.

I was able to drive it to the shop. But had to tow it away.

Strange that it Started and ran great for short bit after replacing fuel pump relay, then erratic to nothing.

Same symptoms when I ran 12v to New zemodex power supply.

It does seem there is a loose connector somewhere, or ground, or possibly the xemodex unit is faulty.

hb00 · Post by **hb00** » 16 Feb 2022, 11:26

Looking closer at coils, it seems they are all original and have extensive cracking.

I ordered a new set from FCP. We will see what that does. The way its acting seems likely the coils could be the culprit.