| Author | Message | ||
     Richard Greene Frequent User Username: benzjag Post Number: 212 Registered: 12-2012 |
One of my buddies just bought a 79 Wraith. He says the idles good and accelerates good with some hestition, BUT will not go pass 70 MPH on the interstate. His pedal is to the floor. Any ideas? Filters? Thanks! Richard | ||
| Hubert Kelly Frequent User Username: h_kelly Post Number: 393 Registered: 03-2012 |
How about checking linkage, it may have been adjusted incorrectly or.... someone wanted to avoid penalty points and made DIY restrictor?. | ||
| Hubert Kelly Frequent User Username: h_kelly Post Number: 394 Registered: 03-2012 |
Richard check/ dash pots may be sticking at certain position thus giving "reduced power" | ||
| Omar M. Shams Grand Master Username: omar Post Number: 2044 Registered: 04-2009 |
Richard, Is the car fuel injected or does it have carburetors? | ||
| Richard Greene Frequent User Username: benzjag Post Number: 213 Registered: 12-2012 |
It has carburetors. Briefly, I WISHED I had seen the car before my buddy bought it, but I'm not jealous but envious! The car was bought by a business man in my town. It was serviced 100% at our local dealer. The tech that does a lot of the "advanced" repairs for the past 20 years on my Shadows remembers the day the car was sold! I will check the oil in the pots and the linkage Monday when he brings it over. Any other ideas much appreciated! Richard  | ||
| Larry Kavanagh Frequent User Username: shadow_11 Post Number: 642 Registered: 05-2016 |
If it has twin SU fuel pumps, possibly 1 fuel pump not working, just a guess. | ||
| Omar M. Shams Grand Master Username: omar Post Number: 2045 Registered: 04-2009 |
Richard, Not just the oil in the dash pots... check that the pistons go all the way to the top of their travel and then back down on their own. Do this check for both carburetors. And as Larry says - check that both fuel pumps are working. It would be worth checking that there isn't a rag sucked into the air intake too. | ||
| Richard Greene Frequent User Username: benzjag Post Number: 214 Registered: 12-2012 |
Since this is US delivered, I think it will have the single Pierburg rotary vane pump like my 78 & 79 Shadow. | ||
| Graham Phillips Frequent User Username: playtime Post Number: 285 Registered: 03-2019 |
G'day everyone,.... You will need to take the piston OUT of the dash pot and clean it and the inside of the 'pot' itself. Do one at a time so you don't mix the parts up. But yeah, not unusual to find somebody had left a rag somewhere it should'nt be. Graham. | ||
| ross kowalski Prolific User Username: cdfpw Post Number: 1429 Registered: 11-2015 |
Richard, What was the story of the car before your friend got it, sitting for a while, how long, where, etc. | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 3059 Registered: 06-2009 |
My 1979 US Spec Wraith II also has the Pierburg rotary vane pump. And just as a data point, my 1978 Silver Shadow II, UK spec, has the dual SU pump, and half of it was not functioning for probably the first 3 years I owned it. It made it from Virginia to Utah and back, across all sorts of terrain and at everything from a crawl to highway speeds. It had no trouble, and there was no difference in its behavior once the pump was rebuilt in 2009. Brian | ||
| Alan Dibley Frequent User Username: alsdibley Post Number: 240 Registered: 10-2009 |
Yes, it's pointless doubling-up on critical components if the machine will not work OK if one fails. I had the same experience before and after rebuilding the two SU pumps on SBH10630. Alan D. | ||
| gordon le feuvre Frequent User Username: triumph Post Number: 349 Registered: 07-2012 |
The problem is how much "hesitation". Is it actually a misfire which would point to electrics/plugs or does it just not want to go. If latter, it is worth venting carb weakener system- that puts partial vacuum on air above fuel in float chamber -to see if this is holding back fuel from flowing up jets even though carb piston/needle is up in dashpot. You REALLLY need to read section K5 of w/shop manual TSD 4200 available n this we site under technical library. Adjacent to "B" bank carb (l/h sitting in drivers seat) is vertical pipe with rubber hoses onto it. Halfway down pipe is blanking cap to test weakener system. Simply remove this cap for your test. | ||
| Richard Greene Frequent User Username: benzjag Post Number: 215 Registered: 12-2012 |
I actually drove my friend's 79 Wraith yesterday. The car idles perfectly, and the engine will rev perfectly in "P" or "N". From start, I had to put the accelerator to the floor for the car to move. It will finally get up to speed, but it is extraordinarily slow. When accelerating (with pedal to the floor),the car has no misfire and is smooth. I disconnected the air filter pipe to the carbs and checked to make sure the emergency brake was not on. After a 15 minute dribve, the brakes are ok and not overheating. The transmission shifts fine. Could it be the converters? Any ideas appreciated! Richard | ||
| Graham Phillips Frequent User Username: playtime Post Number: 293 Registered: 03-2019 |
G'day everyone,.... That sounds like either its not getting enough air or fuel. How are the little fuel filters beside the carbs? Have they been checked to see if maybe they are blocked? Graham. | ||
| Patrick Lockyer. Grand Master Username: pat_lockyer Post Number: 2332 Registered: 09-2004 |
Timing retarded. Exhaust silencers have restrictions due to carbon build up etc. Restriction of the inlet tract. Does the kick down work ok. | ||
| Richard Greene Frequent User Username: benzjag Post Number: 216 Registered: 12-2012 |
Kick down is fine | ||
| gordon le feuvre Frequent User Username: triumph Post Number: 353 Registered: 07-2012 |
Richard, as said in earlier post need to vent weakened system. In addition, need to remove both carb suction chambers/ pistons and clean. At this time chech car needles are tight and at correct height in piston. Then have someone open throttle and check both butterfly’s in fully open position. It is good idea to temp. Wire/ tie coke in open/ hot position as assuming engine cold when choke “on” it always confuses what you are looking at re settings. | ||
| Alan Dibley Frequent User Username: alsdibley Post Number: 241 Registered: 10-2009 |
I had this problem when I bought SBH10630. I purchased a meter designed to check ignition systems and a good ignition strobe. The ignition was timed to about twenty (20) degrees AFTET TDC. It took some time to convince myself it was really that bad, but when the timing was put right the idle speed was uncomfortably fast. Adjusted that, backed down the drive, pointed it along the road and did the usual thing to make it go - put the throttle down. The tyres screamed. Fixed. Alan D. | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 3061 Registered: 06-2009 |
I'll add another to the "check the timing" chorus. When I took LRK37110 to the transmission shop shortly after her acquisition thinking the lack of get up and go was related to that. They checked and said there was definitely no transmission issue, but thought it felt like, "the timing is way, way off." Brian |
