Davo

Tried the wire from battery to coil with the original removed. It ran fine but didnt get me past 3000 I suppose there is the possibility that the Rev counter could be wrong could it? It reads 3000 but is actually much higher? Unlikely I would have thought.

Yes, actually I just filled it up yesterday with £28 worth of unleaded. Im presuming it should be unleaded for a b reg Sierra gl. It has a Vulcan rocker cover on top but Im working on the presumption that it was just for effect rather than cam or timing changes.

I can do the ignition cable quite easily. Is there any harm having both connected at the same time? Ie direct 12v and ignition 12v ?

Ill get on with the line from the battery to the coil after I get some cable. Here is the result of the fuel flow test. Youll see the fuel does flow but it is in spurts. Im not sure if that is a normal characteristic of the mechanical pump.

I did think that it could be the timing when the advance or retard kicks in and the spark happens so far out its completely the wrong time. Ive messed about with that so much though now I dont see how it could be. Ive sent it advanced and retarded but I didnt see any difference.

Ill crack on with the fuel test in the morning. Nothing original ignition wise. I replaced: Coil Distributor Distributor cap Changed points for electronic pickups Ht leads Spark plugs Used this kit from power spark http://www.simonbbc.com/index.php?main_page=product_info&cPath=11_61&products_id=1976

Does the video make the problem more apparent now? Is a pushrod something I can diagnose and repair or is it time to simply get an electric pump to eliminate pump issues?

Thanks for the reply. Its a mechanical pump powered off the side of the engine I believe. I havent got round to testing the flow as you suggest, but a little while ago the fuel line did pop of the carb and was spurting everywhere so. Hardly a scientific test but it does seem like a good flow. I have just take a video. Please excuse the poor shot quality but it will give you an idea. Theres a couple of shots. One shows second gear getting up to 3000 and then struggling to get beyond that. There is another shot which is more typical. Youll see that it teaters around 3000 going on an off the power. Later I then show it stationary at which point it goes way beyond 4000. Interesting I did try easing back on the throttle a little and it progressed slightly more than 3000.

Just an update for anyone interested. I know I still have a bit more To do though. New coil New ignition to power spark electronic ignition New distributor New ht leads And finally today, a new Weber dgv twin 32 36 carb Timing done Mixture set Still, combustion stops just short of 3000 revs. I guess the only step left before looking to the engine itself is the pressure on the fuel line with the engine running. It’s beginning to feel like Trigger’s broom!

Alan, didnt know there was a filter there. Ill get on it. Paul, the metal pipe from the tank Im unsure of but the rubber pipe onward I would completely replace. How would I check for the pressure? I wonder if it would help diagnose the issue if I got a passenger to video the issue.

Hmmm; despite having more power after timing adjustment, there still remains a problem at 2800 revs. Tried powering through but just at the point of 2800 power comes off power comes on. Back to the carb I guess.

Bob, if the above didnt solve it, then yup, I reckon Im back to your theory of the power valve not letting enough fuel in to keep the bowl full when it most needs it! Fingers crossed

Snapper, Im a complete newb but I can read manuals and work out diagrams so thats where my knowledge is lol. All makes sense so far. I got the strobe put last night, warmed it up a bit. Put my finger over the vacuum advance and checked the timing mark. A bit tricky with only two hands but it looked like at idle the mark was about 5cm away from the blade. That seemed way out to me. I twisted the distributor until it was much closer. Instantly sounded smoother. I then reconnected the vacuum tube and gave it throttle. The mark seemed to move which Im assuming is the correct behaviour; regarding the firing to account for the faster revs. Ive not driven it yet due to weather but Im rather hoping my theory might be correct in that because the timing was so far out when the vacuum advance really kicked in at 3000 the sparks were firing at completely the wrong time meaning there was no combustion.

Ok. Just a little update if anyone is interested. Not finished yet but here is so far: New fuel filter put in. Its only a cheap inline one but seems to do the job. Removed the carb. The second throttle jet was definitely blocked so I cleaned that out. I can see it now squirts both throats on throttle. I also took each of the other jets out and bathed them in brake cleaner until I could pass a bristle through. Its definitely running a lot better now but still dies at 3000. Ive tried powering past 3000 but it stutters on off on off power and cannot progress. I guess the next task is timing

All posts very helpful. Ill crack on with the work this week. Many thanks; Ill post back soon with the results I hope.

I assume when you say 40s, you mean jets? Out of interest, if I were to just buy a new carb, what would you recommend for performance and ease of fitting for a novice?

Agent, interesting you say that. I forgot to mention this. Its a progressive carb I believe and the second chamber opens via a throttle linkage. When the first throttle is three quarters open, I can see the second throttle starts to open. However, until a couple of days ago the second chamber was seized shut and the linkages couldnt open it. After a lot of wd 40 and wiggling its now free. I get your point that the jet may be blocked and cant supply enough fuel, however as it works via throttle position rather than diaphragm 3000 shouldnt be the trigger; it would be the throttle position right? The throttle position doesnt seem to affect it. A lot does seem to be pointing toward me at least getting the jets out to clean them. I think I have to do this from within the float chamber which does mean dismantling I guess.

Thanks lp. Just noticed your extra post. As it happens I have replaced the flexi fuel line from the metal part not so long ago. The fuel filter probably could do with replacing. Interestingly if I leave the car for a week or so the fuel line does seem to drain and it takes some good syphoning to get it flowing again. Changing to an electronic igition was actually on my plan of things to do hoping its a suitable job for a novice. I see theres a lot of choice out there though; would you mind posting a link to a suitable one and I can add it to my Christmas list. Ta

Thanks for the tips. I can answer some and will progress with the rest during the week. It feels pretty smooth to the novice ear. No black smoke at 3000 when stationary. Ill have to check with another person when under load. There are some issue with the choke I know. Although I understand from the carb model its actually a water a choke I believe its been converted to manual. However I can see the cable isnt connected. I can however move the lever manually. I see I little movement from the choke flaps but they dont return to their open position naturally so I have accepted the choke isnt working and generally start the engine in the garage where it is a bit warmer and have manually moved the flaps to the open most position. I know this isnt ideal but I was just working on the assumption of no choke function. Maybe this has further implications? Timing is something Ill have to do later in the week with my dad who has the strobe. I am suspicious about the vacuum advance. I really am a novice but I understand that when the carb is under load a vacuum is created in a pip between the car and the distributor to somehow cause it to run a bit quicker. I did hold the pipe whilst revving the engine but to be honest I didnt feel a vacuum feeling in the pipe/tubing. I have taken the tube off and can pass air through it. As I happened to have a spare set, I have just changed the spark plugs. Some a little wet.

Im fair new to all this and have been working through issues with a car that I acquired. So far Ive now got it through its mot. Im now onto performance issues. I have a b reg 84 Sierra gl as the donor in a Robin Hood mk 1 or 2. It has a 2.0 pinto engine with a Weber dgav 32 36 progressive carb I believe. So it starts and runs ok. Up to about 3000 rpm all is good but just over that it dips power which worries me so I change up gears. However, stationary not under load there is no problem revving beyond 3000. Its all pretty dirty at the moment and hasnt really been run for a few years now. Ive used a load of carb cleaner and loaded the tank up with redex which Im hoping will clean the jets through. I probably need to change the distributor fairly soon as my father who gave the car to me tells me the the capacitor isnt currently being used. I know I have that to address but I was wondering if anyone had any advice on other things to look at. David. (BOURNEMOUTH )

Duck, That pressed oval did the job perfectly. It took me all day to fit but as far as I can tell its perfect now. Cheers

Cheers, the fuse box is very tight at the moment as the cables behind it are all cable tied. If I dare cut the cable tie and risk disturbing other problems Ill either be able to find the fault or run a new live. Thanks for the help. Ill let you know how it goes.

Also marked vo 32031

Thank you both. The fuse does appear to be i the black box. The fuse passed my continuity check. So next step was to feed the upper half of the fuse terminal which would have ordinarily be fed by the bottom half with 12v. Doing that the wipers work fully inc intermittent setting. So to me this means Im not getting a live to the fuse. I guess I have two choices now, find the feed wire to that fuse and work out where the break is or make a new 12v feed to that fuse Or maybe a third choice of using a new 12v feed but putting an inline fuse or something. I can see on diagrams that the fuse gets a feed from an ignition relay. Presumably the ignition relay feeds multiple 12v lines. Im not sure what it would look like though. I dont think its so relevant now but the stalk is 83bg11k665*a I cant read the * unfortunately

Hi, I'm just getting to know my newly acquired 84 sierra trimmed with a Robin Hood mk 1. Today's project is getting the wiper to work properly. I don't really understand how the wiper wiring loom works, but I'll talk you through my fault finding process; but please go easy if I've made any glaring mistakes. With the ignition on I can move the wiper stalk to any position or the water pump and neither works. I pulled out the wiper module and put a tester on each of the terminals. As far as I can see there is no voltage on any terminal. If I put a piece of wire from the battery straight to a terminal where the wiper module was the wipers start working. If I move the stalk up and down they even change speed. The washer also works. This must be good news as it means the wiper motor and washer both work. It also must mean that the stalk works. I guess there must also be a working potentiometer in there as well to control the speed. So if all functions exist without a wiper module in place, what does it even do ? Is it for intermittent wiping? A non existent rear wiper maybe? I know there is a rear wiper button on the dash but I have no idea why it's there. I guess the easiest option would be to cheat and directly provide power as I did today. But that can't be right? Can anyone shed any light on what might be happening please. David Bournemouth