Starting issue (Bad aftermarket MAF) new Bosch MAF worked Topic is solved

[Sommerfeldt]

Not a lot of ways to test the fuel filter, except what abscate suggested - get a gauge and check fuel pressure. If it's low, cross your fingers that it's the filter, and change it. Check with gauge again. If no change, worry about pump. If you don't know when the fuel filter was changed last, it's probably time anyway.

- S

[theWIFES_S70]

Change out that fuel filter. Like Sommerfeldt said, if you don't know if it's been changed, it probably needs to be changed. I've seen too many 98s with original fuel filters in them... Not a good move. You might have a big chunk of something in there that gets lodged and dislodged as fuel is drawn into the engine. Lets hope that's the case, considering the money you've spent thus far.

When I replaced my fuel filter, the fuel that came out of it was black and had sand-like grit in it. (Maybe it was sand?) You could even run to Autozone and pick one up for $17 bucks and see if it cures this problem. (Of course, sometime in the next couple of years, you'll want to get a Mahle or Bosch in there...) You can do the job with the wheels on the ground. (But it's a LOT easier when you put the car on ramps.) Good luck. And keep us posted.

[ChadLee]

Replaced fuel filter. Same starting issue. Unplugged MAF, started right up. As soon as the plug is back on the MAF, the engine chokes and dies. Keep the MAF plugged in and the engine will fire up after consistent cranking. Bad MAF?

[Sommerfeldt]

Bad MAF?

Yup. But make sure there aren't any bad hoses and vacuum leaks around that can mess with the MSF readings as well.

- S

[Clemens]

Did you replace the maf with the correct oem part when you replaced it a while back? If yes and you already changed it i would, as suggested above, check electrical connections and vacum hoses around the maf. If not oem, this is most likely your problem.

[ChadLee]

I am pretty sure that I skimped and put in a NAPA maf......shame on me. Sometimes you have fail so you can succeed. That being said, swap it out for a Bosch immediately or are there vacuum tests that I can run to zero in on the issue?

[Sommerfeldt]

It's pretty well known that these cars only like the Bosch units, for whatever reason. It's not exactly clear what Bosch does that the others don't, but they're the only ones that will work right. In my experience, they pay for themselves pretty quickly in increased MPG.

Since the car at the moment works better with the MAF unplugged, it's pretty safe to say that you need to swap it out with a Bosch unit right away. If you still have ~18 year old hoses, then those are probably ripe as well - remember that they sometimes look OK, but will leak under pressure or vacuum. In my experience, rotting or damaged vacuum/IAC hoses, elbows and/or clamps make up about 70-80% of starting/idle/boost irregularities on these cars.

- S

[ChadLee]

If I go to IPD, they have all colors of hoses. Am I ok to just get any 5mm silicone hose and start replacing each, one by one? Thank you for giving me someone to bounce things off of. I have used forums as a resource, but never posted before.

[Sommerfeldt]

Yeah, that's the way to do it. Strictly speaking, there are 4, 5 and 6 mm hoses here and there, but the size doesn't much matter. I've used 5 and 6 mm all 'round. If you want to replace the brake booster vacuum hose (from manifold, under air box, to booster), you need something sturdier in 8 or 9 mm (I think it's .
Like you said, do one hose at a time, so you don't end up with a tangle that can get hard to unravel.

- S

[ChadLee]

If you had to guess how much hose to buy.....10 M?