TPS adjustment - Now Won't Start

[teamer]

Hi,

I took off the Throttle Position Sensor (found out I didn't need to) and after following the service manual procedures for re-installing, the engine turns, but doesn't start.

I didn't have a feeler guage (spec .40) so I used a screwdriver head & voltmeter.

Does the TPS have to be set exactly? Will this throw off my ignition?

Please pardon my lack of experience.

Any help would be much appreciated.

Thanks!

 

[Lextreme II]

Did u install with pre-tension of the tps?

 

[teamer]

No, there wasn't any tension on it when I applied it.

I was following the service manual directions:

1) Place sensor at approximately 45 degrees (on the opposite side) and turn clockwise until there is no resistance shown on the voltmeter.

2) This was done with the throttle part open (specs call out .40mm - however I did not have a feeler guage and used a flat head screwdriver).

Perhaps not having this done using the feeler guage was the culprit - I don't know.

Any thoughts?

 

[sideshow]

easiest way to adjsut it is

turn ign on
check voltage on tps signal wire should be aorund 0.5 volts at idle
then as you accelerate it should go up to 4 or so volts
if the voltage doesnt rise up then the sensor is not fitted correctly

you then can also test the idle circuit
idle wire on tps should have 0 volts and as soon as u crack it it should have 12 volts

 

[cuh8er]

TPS has to be spot on. No real move to move.
Buy a set of feelers and do it right.

40 thou to a mm, so maybe find something that's spot on a mil and use that....?

 

[sideshow]

how spot on does it have to be
look at most workshop manuals and it says .40 to .70 volts
end of day ive never used a feeler strip

as long as u set the voltage to .50 volts
and then the idle circuit is on then that will do

anyway the problems he is having does nto sound like a weongly set tps
if tps is faulty u need to check signal as you slowly open throttle from 0 to 100%

most efi engines have a fuel cut if u crank car when throttle is at 100%

so unless u have a faulty tps which is telling ecu its at 100%
of u have fitted it on wrong then i think the problem is elsewhere
i would go over the rest of the engine

anyway check for spark and check for fuel injector pulse

and also spray something flammable down the throttlebody and see if it starts
then this will tell u that u have a problem in the fuel system so either no injecotr pulse
or no fuel

its not that hard to test

 

[cuh8er]

Well I've only done a few, but the ones I have set, have needed to be within 5ish thou.

Just my .2c anyway.

 

[teamer]

All,
Thank you for your help. I believe the problem is not the TPS - as you may have suspected (something else).

To explain, I was changing the valve cover gaskets, removed/cleaned the throttle body, accidentally removed the TPS and put everything back together & it didn't turn over.

I was a bit frustrated, stopped & left the job (in my garage) for a few days.

But, after thinking about it, I may have yanked the wiring for the fuel line off enough for no contact. Not sure. I did struggle with getting the valve cover off/on and remembered pulling/bending that big wire harness on the passenger side bank to get the cover back on. It was a pain. But, I was worried that I may have bent it enough to break contact (you know when you mess with a 20-year old wiring you may break brittle wires)

Just a theory. I tried again to pull the accessories off again and use a bright flash light to see if I may have forgotten to reconnect an electrical connector. Still have not found any culprit. I am about ready to pull the throttle body off again to see if I missed anything underneath.

I really hope I can find the problem. I am going to have to get a battery re-charger, since the battery is getting weaker every time I try to start it.

Thanks for all your help!

 

[sideshow]

there is afew quick things to test to pin point problems
this works for most efi cars

if u have no check engine light turn ign on
disconnect tps plug and measure voltages from all tps wires to ground
if atleast one wire has 5 volts this means the ecu is atleast turning on

then next step is
remove return line and check for fuel flow coming from fuel rail pressure reg
if fuel is returning then fuel definitely must be getting into rail
it will never be a fuel press prob if its std as ive never seen a factory pressure reg fail
then check for spark
then check for injector pulse

with these simple tests you should pinpoint where the problem is

another quick test is spray something flammable at your own risk
down the throttlebody
if it sort of fires then its fuel related
i never diagnose problems without a can of aerostart

 

[teamer]

Sideshow:

I tore down everything to see if I missed a connector. Could not find any problems.

When I took off the throttle body, I smelled fuel which indicates it's getting fuel.

How do you check for the injector pulse?

Thanks so much in advance!

 

[sideshow]

u need noid light to test inj pulse
plug it on one of the inj plugs

if u smell fuel maybe check for spark

make sure the ignitors are earthed

also front left side of engine manifold about 2cm infront of the injector are 2 plugs
2 or 4 pin and a 6 pin
make sure they ar eplugged in