Running Issues after timing belt replacement

[J4ck100]

Hi all

Just had my LS400 ‘98 timing belt changed today.

Didn’t have much fuel in the tank when i gave it to the garage - they actually said as they were getting it to temp it ran out of fuel so they put a gallon in and finished the job.

I just drove home now and it feels down on power by a fair bit - 70hp at a guess and also is idling funny (feels like it misses occasionally) though does rev out fine. Take a look at the attached video. Every 5-10s the revs at idle dip below 1k then back again.

Initially I thought that maybe that running out of fuel meant dirt was stuck in the engine and that ECU was in some kind of safe mode but now not sure that this is the case and more likely there’s an issue with the timing belt installation.

Going to call the garage obviously ASAP but just wondered if anyone had any thoughts on likely cause? 
 

Thanks

[m4rkw]

It's not a good idea to let a car run out of fuel, especially one that old. All the crap at the bottom of the fuel tank will be sucked into the engine. I doubt it's a timing issue, any reasonably competent garage would verify the timing through the computer before giving the car back to you. Then again a competent garage would perhaps have noticed it was low on fuel and put some in it before leaving it running.

I don't know what may be involved in fixing it if it is caused by gunk going into the fuel system, but lesson learned don't run out of petrol!

[m4rkw]

It could be the fuel pump actually, normally the pump is cooled by the fuel in the tank so it's a good idea to always leave a decent amount of fuel in there to keep it cool. The head pressure also means it doesn't have to work anywhere near as hard when the tank is full compared to when it's nearly empty. If it was run dry there would be an excessive amount of heat generated by the pump which may have caused damage. A fuel pressure test would tell you if that's the issue.

[m4rkw]

Fuel filter is another possibility. If it was run dry all that gunk in the tank will have been sucked into the filter, possibly clogging it up. Since it was technically the garage that ran it dry I think I'd probably take it back to them first and just say "hey something's not right with this, wasn't doing it before" etc and see what happens.

[Mihanicos]

Check the engine timing. Often they miss a tooth and the engine runs erratically.

Chris.

[m4rkw]

1 hour ago, Mihanicos said:

Check the engine timing. Often they miss a tooth and the engine runs erratically.

Chris.

Really? Often? Wouldn’t a garage check the timing on the diagnostics before giving the car back?

[Mihanicos]

The difference of one tooth off is very small. Usually the engine would start but not sharply as before and a slight hick up occurs about mid range. A loss of power and fuel consumptiom increase is a result. If the engine check light does not come on then they would investigate.

Chris.

[m4rkw]

I would expect any half-decent garage to test drive the car afterwards and notice that

[Bluesman]

15 hours ago, m4rkw said:

It's not a good idea to let a car run out of fuel, especially one that old. All the crap at the bottom of the fuel tank will be sucked into the engine. I doubt it's a timing issue, any reasonably competent garage would verify the timing through the computer before giving the car back to you. Then again a competent garage would perhaps have noticed it was low on fuel and put some in it before leaving it running.

I don't know what may be involved in fixing it if it is caused by gunk going into the fuel system, but lesson learned don't run out of petrol!

I have often seen this answer used as  the answer to a problem but I don't think there are any cars out there where the fuel has  outlet pipe which is higher than the base of the tank so your petrol/diesel already comes from the lowest point inside the tank  and that hasn't been a problem by bringing up rubbish in your petrol tanks, so I am afraid that isn't the answer to your problem.

[m4rkw]

I hope you’re right @Bluesman. It happened to a friend of mine once though, ran the tank dry and ruined the fuel system.

[J4ck100]

1 hour ago, Bluesman said:

I have often seen this answer used as  the answer to a problem but I don't think there are any cars out there where the fuel has  outlet pipe which is higher than the base of the tank so your petrol/diesel already comes from the lowest point inside the tank  and that hasn't been a problem by bringing up rubbish in your petrol tanks, so I am afraid that isn't the answer to your problem.

3 people have now said as much and the mechanic who I contacted today has confirmed also that this won’t be the case in his opinion

[Bluesman]

33 minutes ago, m4rkw said:

I hope you’re right @Bluesman. It happened to a friend of mine once though, ran the tank dry and ruined the fuel system.

Well I had a quick Google on it and the worst that can happen is your fuel pump keeps pumping and it gets hot and burns out.

[m4rkw]

1 hour ago, Bluesman said:

Well I had a quick Google on it and the worst that can happen is your fuel pump keeps pumping and it gets hot and burns out.

That still sounds like something you’d want to avoid 

[Bluesman]

43 minutes ago, m4rkw said:

That still sounds like something you’d want to avoid 

Without a shadow of a doubt plus all the inconvenience of walking mile after a mile in the pouring rain when suddenly you come across  a shop where all thing for sale are for  local people only. 

[J4ck100]

Well fair play to those that suggested it was fuel related 

Update: Sorted! 

Timing was fine - an injector was blocked due to debris coming through from the fuel running dry episode.

I have learnt my lesson! Didn’t think dirt could make its way past the fuel filter but I now know that’s not the case seemingly !

[m4rkw]

Sounds like a good result, better than a dead fuel pump!

[runsgrateasanut]

Thats good news. 

It is a fact that for earlier Cars they could either need a 211 rib cam belt or a 210 rib cam belt.  I recall counting the teeth when my mechanic was going to change the belt to be sure I'd been supplied with the correct one. (It was either 210 0r 212 can't quite remember)  but one tooth would make a difference as said earlier in this thread.