Announcement

Collapse
No announcement yet.

Poor running 7A (in my cabriolet)

Collapse
X
  • Filter
  • Time
  • Show
Clear All
new posts

  • #31
    Originally posted by mike74 View Post
    Check your engine earths are all ok, they can cause poor running if dodgy or missing. A strategically placed jump lead from engine to battery negative terminal can rule this out quickly!
    Seem to recall someone some time ago having issues and it was one of the two earthing points at the rear of the inlet manifold?........worth a check.

    Comment


    • #32
      just check the fault codes first, read on the "gerrit speek" site what are the possible causes of the fault codes.
      by randomly replacing parts you behave like an Audi mechanic whose only interest is maximise work...

      Comment


      • #33
        Originally posted by Henkjan View Post
        just check the fault codes first, read on the "gerrit speek" site what are the possible causes of the fault codes.
        by randomly replacing parts you behave like an Audi mechanic whose only interest is maximise work...
        Yeah I will try to do that this weekend. Was hoping to get it through the MOT with the engine as it is though..

        Will also try an extra earth point.

        Comment


        • #34
          Couple of thoughts on the rough running, especially since the engine is a transplant - check the connector for the G62 temp sensor in the head - I and a few other 7a Coupe Quattro owners had issues with a broken connector terminals within the plastic body which cause intermittent faults...and as mentioned check the ECU grounds - on the stock 7a they are attached to the back of the intake manifold by the firewall...that and the ground (earth) strap from the engine to the chassis.
          Peter S

          1990 ErsatzS2 - Pearl/Black track toy
          1991 Coupe Quattro Silver/Black(forever awaiting a 3B swap)
          1991 Coupe Quattro Silver/Platinum
          1991 Coupe Quattro Red/Black
          1995 S6 Sedan Cashmere
          1995 S6 Wagon Silver

          Comment


          • #35
            Originally posted by PeterS View Post
            Couple of thoughts on the rough running, especially since the engine is a transplant - check the connector for the G62 temp sensor in the head - I and a few other 7a Coupe Quattro owners had issues with a broken connector terminals within the plastic body which cause intermittent faults...and as mentioned check the ECU grounds - on the stock 7a they are attached to the back of the intake manifold by the firewall...that and the ground (earth) strap from the engine to the chassis.
            Thanks, searching for the G62 lead me to this page which has great info, thanks Dave? http://forums.quattroworld.com/s4s6/msgs/20985.phtml

            Comment


            • #36
              Tried to read the blink codes but no luck (ofcourse)... connected the light 12V 1.2W as shown in the diagram below, since my doesn't have a fuel pump relay with fuse socket I used a jumper wire from the negative pole on the battery to the L line. Connecting it for 4 seconds on a running engine should lead to the ECU showing fault codes, guess what it... does not.

              Tried an extra earth wire (jump lead) but that makes no difference. Measured the resistance on the G62 sender, temperature was about 15 degrees Celsius showed 3.300 ohms so that's a bit on the high side as it should be 2.500 ohms. Think I'll order a new one though there is very little hope it will one bit, yes I'm a pessimist.

              Blinkcode-Lampe.jpg

              Also came across this SSP which might be usefull to some file:///C:/Users/Patrick/Downloads/ssp_93_192.pdf

              Comment


              • #37
                I have been watching this thread with interest as my 7A had recently thrown a fault code for coolant temp sensor, it was fairly new anyway but I measured my resistance and it was within spec. Brand new Bosch item last year and it reads 3100 ohms.

                My car had been hesitating / jolting on over run now and then and on one occasion let me down at the road side momentarily.

                On hot starts it had been a little slow to catch and go and generally been smelling like it was running very very rich though no MOT or exhaust analyser to verify, it was just one of those smells like an old car running on choke. I have ALWAYS had problems with the occasional stall / bouncing idle at junctions also as do most 7A owners. does any of this sound familiar?

                I read the link from quattroworld and decided to check it out again having read about how the signal affects hot restarting if there is something wrong.

                The pic shows what was wrong with my car - crumbling connector. Who knows how this was affecting things, it may have allowed short between the two pins, may have allowed one or both to slide off the sensor and all of this intermittently. While taking it off, it crumbled to bit completely and luckily i had one in stock ready to use.

                TRANSFORMED.

                no rich smell, seems to drive nicer and no issues idling - it comes back down to around 1050rpm for a second or two then settles at 900rpm. perfect. It is early days of course as I've only done a 10 mile test loop but initial signs are good!

                Have a look at your connector and change if it looks slightly dodgy. I have done 3 of these AMP style connectors now and they have all gone the same way.

                Comment


                • #38
                  All of my fuel injector connectors were crumbling like that, I've never looked at the temp sensor connector although I've replaced the sensor a while back, worth a look. ISV connector would be a good one to check too.

                  S2 Coupe 3B Project


                  Ur quattro restoration

                  S2 Avant

                  Boost is the new rock and roll!
                  sigpic

                  Comment


                  • #39
                    I've done the ISV and TPS connectors. I may well do the injector connectors as well as I can't help thinking that a good number of issues on these cars are caused by failing electrics. The worse thing about that is they don't tend to go outright straight away but give you a period of bother before it gets bad enough to find.

                    Comment


                    • #40
                      I was getting random pinging leading to ECU pulling timing, injectors weren't always firing properly.

                      S2 Coupe 3B Project


                      Ur quattro restoration

                      S2 Avant

                      Boost is the new rock and roll!
                      sigpic

                      Comment


                      • #41
                        Still on the stock 7a Hitachi injectors?
                        "Nulla tenaci invia est via"

                        Comment


                        • #42
                          Not for me, changed to Bosch red ages ago but they are the same electrical connectors. I don't know what the original poster is using, I suppose that original hitachi could be part of his problem if they are stuck / dirty and staying open more than they should

                          Comment


                          • #43
                            Yes peeps it's still on the famous for failure Hitachi injectors, not liking the idea if spending lots on new injectors on a car that isn't staying anyway, but I want it to run right before selling it. Thinking the problem might be in the injectors or FPR. Hope to have some other parts to try soon.

                            Checked all connectors and they look good, already instally new crimps in the G62 connector.

                            Comment


                            • #44
                              If you find out it is the injectors; I have a set of Bosch grey injectors mounted in a freshly powder coated fuel rail that I don't need. ..

                              Comment


                              • #45
                                Originally posted by steve briance View Post
                                If you find out it is the injectors; I have a set of Bosch grey injectors mounted in a freshly powder coated fuel rail that I don't need. ..
                                Have just bought original injectors and FPR this afternoon so I will try if it makes a difference...

                                Would your set be plug and play or does it require other parts to work and how much would you be looking for?

                                Comment

                                Working...
                                X