Long as you're happy with it in the end really, personally this is why I want it all done in my drive way. Wouldn't take the car back to them in all honesty mate.
I'd strongly advise going somewhere who knows how to tweak digifant 8v's to have it setup. Determining how advanced/retarded the cam timing is cannot even be done roughly by eye unless the cam cover is off and engine set at tdc. I'd personally put the vernier to 0degs and then advance it from there in 1deg increments up to maybe 3degs? Don't worry about pistons hitting valves. Not an issue! From personal experience with various different digi cams, they all gave their best results running advanced. Retarded cam timing kills mid range but gives no more top end. Certainly you should notice more low and mid range puff as you advance it up....
Plenty of scope for going 3 or 4degs either way from zero if its all timed up properly... My bet is a couple of degrees advanced would be ideal with a gs2h. Cancels out the retarded timing due to any head skimming and restore some mid range punch..
Iv been playing with my cam timing and I found around 4-5deg was pretty good though my dizzy is stuck at 6deg Im going to loosen but should I add a couple more degrees? I am going to get it sorted on the rolling road soon but just havent had the time.
Hi Chris Car has been back to the garage and they have fitted a brand new VAG distributor which I picked up for 86 from the dealer. Dizzy came with cap, hall sender and rotor arm included. Misfire has now gone and I have had no further coolant issues. So...the car is running okay but really does feel pretty lethargic low down!! I also drive my girlfriends 8 valve gti and that feels more nippy lower down, but doesn't have the same urge higher up the rev range! I think I will put a few more miles on it (done about 350 now since the rebuild) and then get it to a knowledgable RR place. Most people on here seem to rave about Stealth?? There is a RR in Chester at A B Garage that has an 8 week waiting list but don't know how good they are with Mk2's!!! Any suggestions?? Cheers Paul
Because the dizzy is set to allow easy cranking and starting (retarded). If you rotate more advanced the engine will gain torque and the car will feel more lively. But...because the engine is running off a map designed for a smaller engine, and you have have just shifted the entire spark map, there are speed and load points where the lookup + your dizzy offsets will NOT be matched and the engine will run into det. For some backing off a little on the timing will be enough to make them feel happy. But for those who know, this method is compromising the entire point of this conversion. Also digifant runs fairly lean which does not help. Really does not matter who attempts to rectify. They may try to work around the system, but in the end the hardware and controls are mis-matched...Think your garage has done well so far. Suggestions; Try increasing dizzy advance slowly interations) balancing between good starting quality and top end det ( pinging). Having a later MK3 020 reduction starter motor helps starting torque, to allow more base advance. May need to tweak AFM ot offset engine leaness.
Being a mk2 digiphant, will it not have the knock sensor controlling the det so he may not hear it as he advances it each time?
If the actual spark as seen by the engine is already high, because the static dizzy setting is already offset from "base", what the ECU will pull back will not be enough to stop audiable det on what is a 10.5 CR engine with a larger bore. The system when used on a 1.8 PB motor is fine for what it was intended. Remember the spark table is not linear.
Toyo, I thought this was agreed to be an 1800 bottom end, not a 2L??? Paul, I personally think the mechanic has mistakenly gone the wrong way with the cam timing. He should have gone in the ADVANCED direction to give more low and mid range power... You will be perfectly safe setting it to neutral (0degs) for starters and I bet you will find low end response improves...from there you can then advance it further to suit
Hi ChrisMc/Toyotec The new bottom end is definately a 1.8 block!! As for the vernier timing, the reason the mechanic gave for setting it retarded was that "I had asked for the engine to be set up to run with as smooth an idle as possible and lots of low down pulling power". Unfortunately the idle isn't that smooth and also the low end power seems to be seriously affected, so I am really not sure why the garage set it up that way??? Their reasoning was that if the cam timing was advanced then I would have a horrible rough idle? How straightforward is it to adjust the cam timing to 0 degrees? I am a bit of a novice really and don't want to mess things up?? Wouldn't I just be best taking it to Stealth? Cheers Paul
changing it to zero is a few minute job, remove cambelt cover, loosen all 4 allen bolts on the vernier and then adjust, you will most likely need to turn the bottom pully with a 19mm socket to adjust it, just make sure the belt stays tight and doesnt jump a tooth on any of the pulleys.
If you're going to adjust it yourself have a look at this, and this Might be of some help as I've recently been playing with cam timing.
Cam timing is dead easy to adjust! I'd firstly put the car in gear with handbrake released and rock it until the scale on the vernier is at the top and, thus, easy to read. You then have to loosen the 4 Allen screws on the vernier and use a 19mm spanner on the cam pulley bolt to turn the cam... It's then a simple case of lining up the pointer with the 0deg mark and tightening the Allen screws back up.. Your mechanics reasoning for setting the cam timing as it is sounds way off to me. As I have said previously the cam needs to be advanced for low down power. The idle will always be slightly lumpy as it's an aftermarket cam but shouldn't be rough... Neutral or advanced timing certainly won't make the idle any worse. Just be sure not to take the mechanics word as gospel as he has already spun you yarns about the dizzy and the cam timing...
My mistake. Keep associating 135bhp with 2l 8v for some reason . Ignore what was said in my last post.
Further engine issues..any clues?? Well after a few further issues with my car I have managed to get a few things sorted! My car was back in the garage today to fix a slight coolant leak which was dripping from the gearbox bellhousing. Turns out it was a slightly cracked black plastic coolant union! Got a new VAG one fitted. After replacing the distributor with a new VAG one and new Bosch leads, the car still has a slight stutter/misfire but very occassionally??? The garage suggested it could be plug leads so I paid for a new Bosch set and the problem is still there? It is very occasional and it seems to happen when the car is pointing uphill but not exclusively??? Could it be a fuel pump related? Garage seems to think so? The rev counter seems to stutter when the car misfires?? Any clues? Cheers Alpenweiss2
Check the lift pump and pickup hose for operation of the pump and damage to the hose.. The fuel system should be at 3 bar pressure, so the odd hill shouldn't make any difference, unless it's not picking up properly from the tank.
Sorry to be dim Mike..but how do I check it..will it be in the Haynes? p.s. Spoke to the garage and they have said to take it back in next week when they are not so busy and they will take it for a long test drive (20 miles or so) so the mechanic can experience the symptoms. It is so intermittant..thats the problem in diagnosing it! Cheers Paul
Before you do this, it's worth asking how much fuel was in the tank. If you only have the problem on less than half a tank, then it could well be a lift pump issue. Take off the inspection cover in the boot, undo the big plastic nut (a hammer and a drift/bar might be needed) then unclip and remove the hoses. Pull the lift pump and sender unit out of the tank. Visually check the pickup hose for splits and holes. power up the lift pump from a spare battery, and see if it runs (it'll buzz rapidly) You can check if the lift pump runs without removing it, but these cars are getting to an age where the hoses can be in a poor state. The pump could run, but it still needs to have a good pickup hose to suck fuel from the tank. To check it's running without removing it, 1. Unplug the electrical multiplug from the main fuel pump. 2. Bridge the big terminals where the fuel pump relay plugs into the fuse box. 3. Switch on the ignition, and you should hear the lift pump buzz. If it's all normal, then see if your garage can do a fuel pressure check. It's also worth checking that your rotor arm and dizzy cap aren't cracked or damaged. I suspect they're brand new, given all the work you've had done, so they should be ok if they're the correct parts, and were fitted correctly.
is the garage cutting you some kind of special deal on all this stuff? these cars aint hard to work on , sounds like they aint too clued up. id suggest you find somewhere else that can diagnose and fix it all ...unless theyre doing stuff really cheap or free i think theyre taking you for a ride now
