Lacking Top End Power

[nefarious]

Hey guys, the process of fixing up this gen4 (which I've now ended up getting as a freebe) continues. Most of the major stuff is sorted but it does feel like its lacking a bunch of power, especially at the top end (revs build cleanly enough, gets much louder, but power stays flat - perhaps even dropping off a bit).

Suspecting a fueling problem I pulled two of the plugs and they look healthy enough (light brownish-grey), so for the moment, I'm assuming that air and fuel are OK.

There's no check engine light showing so I guess there isn't much point in going through the diag proceedure (jumping the two pins on the interface socket).

Two suspects are:

1) The T-VIS - I've been told that there should be a noticable change in engine note and a significant step up in power at 4.3k revs. There isn't. There's a *slight* hardening of the engine not at about 4.8k, but you'd really have to be listening for it. Any thought on how to check this (given that the 'puter says nothing's wrong).

2)Spark. The car has 80k on the clock, so it probably deserves a new dizzy cap, rotor arm and plugs. I know I'm being a tightwad, but I don't particularly want to Shell out £45 only to find it makes no difference at all. Is there anything I can do to check this? Also, does anyone know off the top of their heads what the resisance on the primary and secondary windings of the coil should be?

Cheers in advance...

N

[daktari]

Hey guys, the process of fixing up this gen4 (which I've now ended up getting as a freebe) continues. Most of the major stuff is sorted but it does feel like its lacking a bunch of power, especially at the top end (revs build cleanly enough, gets much louder, but power stays flat - perhaps even dropping off a bit).

Suspecting a fueling problem I pulled two of the plugs and they look healthy enough (light brownish-grey), so for the moment, I'm assuming that air and fuel are OK.

There's no check engine light showing so I guess there isn't much point in going through the diag proceedure (jumping the two pins on the interface socket).

Two suspects are:

1) The T-VIS - I've been told that there should be a noticable change in engine note and a significant step up in power at 4.3k revs. There isn't. There's a *slight* hardening of the engine not at about 4.8k, but you'd really have to be listening for it. Any thought on how to check this (given that the 'puter says nothing's wrong).

2)Spark. The car has 80k on the clock, so it probably deserves a new dizzy cap, rotor arm and plugs. I know I'm being a tightwad, but I don't particularly want to shell out £45 only to find it makes no difference at all. Is there anything I can do to check this? Also, does anyone know off the top of their heads what the resisance on the primary and secondary windings of the coil should be?

Cheers in advance...

N

Hi. Firstly, You would be well advised to replace the dizzy cap, Rotor arm, plugs and plug leads. If they are the original items they will be well on their way to ignition heaven. Especially the Dizzy cap and rotor.

Likewise the air, oil and fuel filter should be renewed. Once thats done you need to check the ignition timing with a strobe lamp.

Making sure the pins E1 and TE1 are bridged. Timing should be set at 10° BTDC. Once thats all done and you know that the ignition components are ok, you can move on to the fuel system. But hopefully that`ll sort the problem out.

[nefarious]

Filters etc have already been doneas part of my normal new car routine.

What's the E1/TE1 thing? I'm assuming you mean of the diag port/box thingy on the rear nearside corner of the engine bay? Is that what brings up the fault codes?

[daktari]

Thats the one. Needs to be bridged before timing can be set.

[nefarious]

Thats the one. Needs to be bridged before timing can be set.

Cheers m8y. I'll be on it at the weekend.