My sons 245 wagon died from what we found to be a fuel issue. Sure enough, the in tank pump was dead and the gas gauge also was dead. Upon removal, we found the wire/plug to the top of the fuel pump assembly was gone completely... Wires dangling.. So we removed the assembly and upgraded to an AEM aftermarket in tank pump and re installed it.

This pump flows much more than the stocker and would provide a good pump for future planned mods. This same pump was used on my 940 and in his 242, so they are known to be reliable. The filter was also changed and the under car pump was deleted, as in all our other AEM installations.

The key was cycled to remove the air and prime the injectors... the car started then quit.. then it wouldn't start.. then we go it going with a shot of starting fluid.. then it settled down and idled..

Now the funky stuff happens... It idles ok, and will rev, if you work the throttle very slowly. open it quick and it dies out.

After an internet search, the mass air unit was mentioned and it will run without it... according to IPD website, the fuel pump relay gets fried when the in tank pump goes out, so that was replaced. no dice..

We swapped on another fuel pressure regulator, same thing..

I appears to be a fuel related issue as nothing else was changed or disturbed. It ran fine up until right now.

Ideas?

Thanks!
Mike

 

AMM replaced with a good one, same thing.. almost tries to start but won't. It will start with starting fluid, run for a minute or so, then die. Diagnostic codes pulled.. test one 121, test two; 332, test three; 331... I'm stumped.

 

Are you sure the new fuel pump is OK? Just because it's "new" it shouldn't beyond suspicion. Many problems with aftermarket parts.

 

Hi Lev,

Thanks for the reply. My son an I discussed that possibility yesterday and we are going to rig up some sort of fuel pressure test. There is no test port on the fuel rail, so we need to figure out something else. I suppose we should see about 45 psi output? The pump we used was used before in my 940 and I'm beginning to think the seals in it dried up.

Cheers,
Mike

 

LH2.4 should be 42 PSI relative to manifold vacuum, +/- 2 PSI

you need a fuel pressure test kit that has a T-fitting with the same threads as the fuel hose-to-fuel-rail connection.

 

Hi pierce,

I've rigged up a test gauge that I can hook right onto the output line before the filter. Perhaps ill get to it tomorrow, as I'm at a family picnic today, lol. Hopefully it's a crappy pump. In the mean time I cleaned the firewall ground strap connection, spray cleaned the MAF connector, and went thru all the fuses with fine sandpaper as well as the fuse holders on the car. It started right up and actually idled for a while but slowly choked out and died. It started right back up but then had the rev issues as before. Ill let you know what the pressure reading is with my "rig" I made.. Lol

Cheers,
M.

 

Update,

We went out and picked up a very large fuel pressure tester kit at harbor freight. Unfortunately, the smaller kits lacked the metric fittings. Anyway, the fuel rail pressure hose connection was destroyed in the process, so extra work had to be done to remove it. Once apart, the gauge was hooked up and the pump could only push a meager 5psi. So the pump was pulled to bench test it. Once on the bench, there was a split found in the bellows joint of the short rubber pump to hard line connector hose.

This must have started a long time ago as a pinhole, and the new high pressure pump must have ripped it open even bigger. A short new piece of line was added and reinstalled. The rail now gets just over 50 psi. The car started right up and is fine.

So it appears fuel delivery issues could be tied to code 121. A pressure check will quickly verify things. Also, the next pump I replace will include replacing the connector hose as well.

Cheers,
Mike