First drive and seriously rough hesitant jerky acceleration.

[SteveyP]

Hi all

Need some advice please. Just picked up Vin 4468 from Chris in Essex (UK) and had some serious acceleration issues on the way back from his place. After about 70 miles it started to accelerate very roughly. Under any sort of load (in any gear) it was hesitant and jerky. I stopped at Reading services (got swamped by people LOL). Let it cool down, started it (idled OK-ish, revved lovely and smooth) and then set off again - marginally better for a while then got progressively worse and worse. In the end I couldn't go anymore as acceleration was scary bad. So it was recovered back to Bristol (not at all how I envisaged my first drive back after an 8 month resto.)

Any ideas? I am thinking more than likely fuel related - but apart from that it could be one of many things it appears. It is a newish fuel pump but it could be that. Or just the hose collapsing in the tank. Or fuel distributer faulty. Or???

What are your thoughts?

Thank
Steve

[sdg3205]

It could be any of those things.

If it gets worse as it gets hotter, then it could be the pick up hose. I've also had coils act in a similar way. A few of us had coils go south. It's a super quick swap I you want to eliminate spark.

Was it raining? Was the engine sprayed with a hose? Check for water in plug wells.

As for the fuel, when its hot again, pull the injectors and check the spray with 6 clear bottles. There are instructions everywhere for this.

Check base timing with a gun too.

[SteveyP]

Hi Dave

No it was dry, and engine was bone dry too. Some say it could be a bad Earth on the fuel pump? But it could also be one of many other things it appears. It's going to be an elimination process I guess.

It had been running fine on short trips with Chris Nicholson, in fact he had had no running issues with her. But it was this longish 170 mile drive back home that showed this particular problem up.

Thanks
Steve

[sdg3205]

Totally.

If Chris did the restoration my guess is that he did everything properly. A bad coil won't rear it's head until it gets hot. I used to get about an hour of driving until the coil would conk out.

Double check with Chris about what he did with the fuel system, if he checked operating pressure etc.

You can run a quick voltage test at the pump by removing the access panel and driving around, testing every 10 min or so. Not sure how you'd loose voltage over time, a bad ground should be constant hot or cold.

[Jonathan]

...my first drive back after an 8 month resto.

...What are your thoughts?

Steve, is the fuel in the vehicle newer than 8 months? Do you still get this same jerky acceleration with a tank of brand new fuel?

[SteveyP]

Thanks guys appreciate the advice.

Chris had cleaned the tank out and run it with new fuel only. I topped it up to fullish (can't tell for sure as fuel gauge just showed full/ half full intermittently over the trip back). Everything fuel wise has been replaced (only the pump was left as it was bought in 2008 and appeared to be ok)

The coil was replaced with a new one. But sounds like it could still be this - it did start to hesitate and stutter about an hour into the journey. I agree that if she runs OK cold then it can't really be an earthing issue.

He warned me about engine temperature on such a long and untested run (especially as she had not been run properly for many many years). So I watched the temp gauge religiously. But that was fine - new radiator, water pump, otterstat and pipes all worked well. Brakes required a hard shove to stop, I presume this is normal though?

Steve

[DCUK Martin]

Brakes should feel pretty much like a modern car except the fade when you work them hard, not being vented. The power loss sounds pickup hose related. Check pickup filter and also if the pickup hose is a remanufactured replacement or original?

[SteveyP]

Thanks Martin

Everything in the fuel tank was replaced with one of Ed Udings kits (apart from the pump - as that was fairly new already). Would his pick up hose still suffer from the collapsing type issues too? Do I need to buy a new fuel filter, or just clean the old one out?

With regards to the brakes, I haven't driven another DeLorean before so not sure what they should be like tbh. But they weren't confidence inspiring that's for sure. Apart from new master cylinder, new stainless brake lines and a system bleed, they didn't have much attention (I think Chris N was relatively OK with them). Does it sound like a knackered power servo unit? Or do I just need to get everything replaced/refurbed (I'm thinking refurbed callipers, new discs and new pads).

Thanks
Steve

[David T]

Thanks Martin

Everything in the fuel tank was replaced with one of Ed Udings kits (apart from the pump - as that was fairly new already). Would his pick up hose still suffer from the collapsing type issues too? Do I need to buy a new fuel filter, or just clean the old one out?

With regards to the brakes, I haven't driven another DeLorean before so not sure what they should be like tbh. But they weren't confidence inspiring that's for sure. Apart from new master cylinder, new stainless brake lines and a system bleed, they didn't have much attention (I think Chris N was relatively OK with them). Does it sound like a knackered power servo unit? Or do I just need to get everything replaced/refurbed (I'm thinking refurbed callipers, new discs and new pads).

Thanks
Steve

If it seems to get worse as the level in the fuel tank drops and the car gets hotter, I would inspect the parts in the fuel tank. The pick-up hose may be collapsing or is kinked.

[SteveyP]

Thanks David, will do. That's my first port of call. Won't be till the weekend now though.

Steve

[Ryan King]

I had a very similar issue which resulted in my fuel pump cutting in and out and eventually dying. A replacement of the pump brought things back to normal. I would pull the pump and test it.

[dmc4087]

I had similar issues when a fuel pump was going on my car - and it wasnt that old either.

The pump was making a racket though (although you probably wouldnt hear this if you were driving on the motorway).

The brakes should be fairly good too for the power of the car.

[SteveyP]

Could be the pump I agree. It was the one weak point of the fuel system as I didn't replace it. I'll check the voltage to it first to make sure that is correct (hot and cold). And if that's OK then I shall start replacing a few items.

Cheers
Steve