[SOLVED] Added temp gauge, van now starts/runs poorly…???

[Paulbeard]

87 Westy, inline 4 with FAS ECU.

I added a temp gauge and somewhere I must have bumped something along the way when I installed the sender.

The van doesn't start properly (takes many cranks, vs the almost instantaneous starts I am used to) and it runs very roughly, will take no gas until it's warm but still doesn't feel right at all. Seems to stumble a bit at idle and the idle is high: at one point as I was idling to test the gauge, it went over 2000. Not usual at all.

I didn't disconnect anything to get power in the engine bay or anything, just tied into an existing ground. But I wonder if I did something when I took the cluster out (which in hindsight was unnecessary) or when I was running the signal wire under the body.

What should I look at, given that it starts and runs, after a fashion?

EDIT: sounds like it might have been coolant on the OG sender causing the ECU to get confused.

EDIT 2: VDO writes:

[Vanagon Nut]

Looking at this previous post of yours:

https://www.thesamba.com/vw/forum/viewtopic.php?t=707523&highlight=gauge

do you now have two temp gauges? If so, did you alter what appears to be the existing 4 pin temp sensor(s) wiring shown in your image below?

This image shows what appears to be the 4 pin temp sensor(s) that was (or is) supplying input to the temp gauge and ECU. It sounds to me like something has been altered at the wires providing temp input to the ECU.

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1981 Westy DIY 15º ABA

1988 West DIY 50º ABA

VE7TBN

[Paulbeard]

I didn't touch the existing gauge/sender and didn't add anything to the ECU. It's a signal wire to the gauge and then just 12V +/- to make it work. I must have buggered up something behind the dash or under the body, as best I can make out.
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Currently -> Frida: 87 Tizian Red (mostly) Vanagon GL Westfalia w/ 2.0L ABA conversion
Formerly -> Steward of a 73 Super Beetle (Beater) and 67 Beetle 1300 (Little Max) both names by POs

[Vanagon Nut]

Ok. Ya, could be something got knocked around. Or, assuming the ground connection work is good......

If you disconnected the battery, maybe the throttle body needs to be aligned? I'm assuming the FAS stuff is OBD2:

http://wiki.ross-tech.com/wiki/index.php/Throttle_Body_Alignment_(TBA)

Neil.
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1981 Westy DIY 15º ABA

1988 West DIY 50º ABA

VE7TBN

[Paulbeard]

[Vanagon Nut]

I looked at old posts here, seems you likely have Tiico engine management so ya, as you say, likely OBD1 or something like that. However.....

FAS shows new Tiico throttle bodies. They appear to have the "motorized" throttle body. If your throttle body is the same and battery was disconnected, that might require that a TB alignment needs to be done. I bet the Tiico Yahoo forum has info on that.

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1981 Westy DIY 15º ABA

1988 West DIY 50º ABA

VE7TBN

[Vanagon Nut]

[Paulbeard]

[Vanagon Nut]

Well, coolant works well enough to make the connection between the probes in the coolant tank so for sure. Given the angle and location of the 4 pin temp sensor, ya, maybe coolant seeped in and shorted out (completed the circuit) two or more pins. If that happened to the temp sensor input to ECU, the ECU would see near or zero Ohms which would really mess it up; it needs a resistance value as shown in the temp sensor graph. i.e. it needs to see open loop (cold engine) and closed loop resistance values.

Engine running, slowly move that set of wrapped wires to temp sensor(s). See if that causes a run issue. Or, ring them out with a meter while doing same.

Those wires to sensor look OE so each should have a small silicone seal on it where it enters the connector housing to keep water etc out. Easy to check. That said, coolant could've gotten in via the small openings the clip uses.

Neil.

silicone seal I referred to

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1981 Westy DIY 15º ABA

1988 West DIY 50º ABA

VE7TBN

[Paulbeard]

[crazyvwvanman]

If you are trying to use a VW gauge temp sender with an aftermarket temp gauge then you are not going to get an accurate gauge.
You need to use a temp sender meant for that gauge.

Mark

[Zeitgeist 13]

You may need to look into your thermostat, as that's a rather low operating temp. Personally, I think rather than doubling up the coolant temp, you could/should use a sender on the oil filter flange in order to monitor oil temps. On my TDI swap, I find that oil and coolant temps closely follow each other. My operating temps tend to stay in the 180-190F range. Even though that gauge says coolant temp, it could easily be used to monitor any drivetrain liquid. Mine has a switch to toggle between transmission and engine oil temps.
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Casey--

'89 Bluestar ALH w/12mm Waldo pump, PP764 and GT2052
'01 Weekender --> full camper
y u rune klassik?

[Vanagon Nut]

[Paulbeard]

[crazyvwvanman]

Nowhere does that sender link say it is for a VDO 250 degree gauge.
The VW replacement sender you chose is for a stock VW gauge.

The rad fan turns on based on rad temp, not engine temp.
But of course the radiator isn't going to be hotter than the engine coolant that is reaching it.

There are a couple different heat range rad fan temp switches that could be in your rad so when the fan comes on varies.

Most VW engines use a 87c thermostat and that means it BEGINS to open at that temp. Your fan is coming on while your newly added gauge says the engine is still to cold for the thermostat to start to open. The rad doesn't get coolant until the thermostat opens. In other words your new gauge reading is nonsense, way low.

You need a VDO gauge sender, meant for a 250f VDO gauge. Sadly I don't see one that will slip right into that plastic VW hose flange.

Mark

[Paulbeard]

[Zeitgeist 13]

The vendors who sell VDO aftermarket gauges will definitely have sending units for their gauges. VW actually used those gauges/sending units for Mk1 and Mk2 Scirocco, GTI, GLI and Cabriolet cars.
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Casey--

'89 Bluestar ALH w/12mm Waldo pump, PP764 and GT2052
'01 Weekender --> full camper
y u rune klassik?

[Paulbeard]

[atomatom]

you really need to buy the sender and gauge as a pair.

however, they nearly all work on the same principle of resistance, which increases (or decreases) as the temperature changes. if you are lucky they'll have the same resistance spec - but that is pretty unlikely.

anyway, a cheap(ish) piece of equipment that is critical is an IR thermometer. about $40 and you can check to see how badly your gauges are lying to you.

also, with gauges, make sure you wire the power to something that switches off when the key is out. if the gauges stay up when the key is out, you've got some power drain there. that was killing my battery slowly - damn the PO and his electrical aspirations.
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84 Vanagon Westy, 1.9L, California raised but defected to Canada.

[82westyrabbit]

Hi Paul. A lot has gotten covered here. The wiring diagram for your Tiico engine is available at the Tiico Yahoo group. The four pin connector has two temp sensors in it one for the ECU and one for the temperature gauge. They are completely independent of each other. So if your running issues reappear It must be a bad conction (probably a ground wire). All the Tiico wiring is in the back so your dashboard work should have no effect on how it runs unless it doesn’t run at all because of no keyed power. I ck my temp gauge anytime I do cooling system work. I run my van at 180f or 82 Celsius that’s a little on the cold side so I can leave my cap off with a thermometer in cooling tank and watch the temp and when the thermostat opens. If you can verify what temp goes with what reading on your gauge you could just remark the gauge and continue on. I my case my second temp gauge is oil temp and that should follow pretty closely to water temp. The Tiico ECU is not really obd 1 or 2 it is pretty much all by its self. It only works with Ross tec software or vag tool to the best of my knowledge. The fuel management system is supposed to set its self up on every engine start so you should not have to set anything up after the battery has been disconnected. At lest I never have. I hope some of this is helpful. John