1.9 petrol carb query

[kevinfromireland]

Just joined. One question.

Situation: Have been experiencing intermittant performance with my '89 van which I suspect is due to a worn diaphragm in the Pierburg carb. Looked to buy a Weber but no joy. Bought a kit to fix Pierburg but afraid to attempt the job. Came on a guy today that was replacing a petrol engine with a diesel one locally due to overheating of the petrol. The carb in the removed petrol one was identical to mine so i bought it (attached to the inlet manifold). Replaced it, including manifold this evening and engine is now running at VERY high revs even with accelerator cable disconnected.

Suspect either.
1) The inlet manifold gaskets (which I didn't replace and one was torn. Have just ordered two from JustKampers.
2) That there are different settings in the carb for different T25 petrol models causing the high revs in my one.

Question: Could (2) be true??

Kevin

[kevinfromireland]

BTW, the donar van carb was an '86 petrol

[CovKid]

Carb swap should be fine. However, you'll need to look at idle speed adjustment and possibly re-check timing. Did the choke open fully?

It could simply be that old carb had minor air leaks here and there (or even via inlet manifold) and idle speed had been adjusted over the years to compensate. Now its all been replaced and airtight, the idle speed is higher. That said, you'll still need to adjust the carb anyway so it matches the needs of your engine.

You might like to read this: https://onemanspanner.wordpress.com/201 ... w-vanagon/" onclick="window.open(this.href);return false;

[kevinfromireland]

Thanks CovKid. Will get back to it on Monday. Much appreciated.

Since you mentioned the choke and how it works, I'm thinking that I may have messed it up myself. When I initially got it started with the replacement carb, I ran it for 5 minutes to test it, it overheated which I found was due to lack of coolant. My bad as the van had been sitting for a while and obviously it's leaking coolant. So perhaps the choke fried.

Again, will be back to it early next week.

Kevin

[kevtherev]

I doubt you did any damage to the choke.
Overheating warps the heads.

[ghost123uk]

If you do a search of Kev's posts you will find lots of info on how to set the carb up correctly. Kev is our resident expert on them. Here is a link to some of his posts on the subject Click here

Hey Kev, I ain't going to look through all your posts , but was wondering if you have one you know of that has a pretty comprehensive set of advice that perhaps could go in the wiki?

[kevtherev]

https://club8090.co.uk/forum/viewtopic.p ... b#p7823634" onclick="window.open(this.href);return false;

Two birds one stone.
Cov kid got the ball rolling though

[kevinfromireland]

Thanks guys. I'll check it tomorrow.Fingers crossed, I moved the van early today and revs were back to normal again. I'm hoping that the 5 minutes without sufficient coolant somehow caused a 'temporary' high revs situation at the time and that now (with sufficient coolant), everything is OK. The replacement carb that I used was apparently working fine with the previous engine.

Kevin

[kevtherev]

Your carb has a fast idle mechanism for cold starting.
It is engaged when you start the engine according to the manual.

2500rpm is the first setting
Frightening if you ain't expecting it

[kevinfromireland]

Thanks guys, hopefully less one problem now.

Replaced both inlet manifold gaskets and she is reving no more. Before the new gasket, it started fine and then 'built up' to a heavy rev.

She is still loosing coolant when sitting but that's the next job. Seems to be dripping from the offside rocket cover but can't see from where even from under the van. Guessing the water passes through the choke above. And the guard below the rocker cover doesn't want to come off. Working it

Thanks again.

Kevin

[kevtherev]

It's likely that the head seal is leaking.
But let's hope it's a hose.

[kevinfromireland]

Not really familiar with the engine (yet).

Is the 'head seal, the head gasket?. If so, I doubt it's leaking because it's now ticking over fine and it lost the full expansion tank and 2 inches of the main tank over the last two day just sitting there. Still early stages. Taking it for a drive now to see how it runs.

[kevtherev]

No I mean the head seal.
WBX engines don't have head gaskets as such.
The head seal will leak with or without the engine running.
You need to pin it down

[kevinfromireland]

Thanks Kev.

I took the van for a small drive. First ran it in the shed and everything seemed great. Drove two miles, she ran smooth, responsive and not highly revved. Parked it for an hour as went for a walk. On the two miles home, it bucked for a while and then gradually lost power and I just about got it back to the shed. Now it revving high again. Choke is opening fully. Plenty of coolant and nothing obvious wrong other that revving high in the shed.

Too many variables for my limited expertise.

I've registered for the http://www.type2ireland.org/" onclick="window.open(this.href);return false; forum and when approved, will see can I locate a T25 expert in Ireland that I can trailer the van to. Need to also read more about the van. My knowledge is somewhat limited to the classic Saab 900s and the good old 2CV.

Kevin

[kevtherev]

Thanks Kev.

I took the van for a small drive. First ran it in the shed and everything seemed great. Drove two miles, she ran smooth, responsive and not highly revved. Parked it for an hour as went for a walk. On the two miles home, it bucked for a while and then gradually lost power and I just about got it back to the shed. Now it revving high again. Choke is opening fully. Plenty of coolant and nothing obvious wrong other that revving high in the shed.

Too many variables for my limited expertise.

I've registered for the http://www.type2ireland.org/" onclick="window.open(this.href);return false; forum and when approved, will see can I locate a T25 expert in Ireland that I can trailer the van to. Need to also read more about the van. My knowledge is somewhat limited to the classic Saab 900s and the good old 2CV.

Kevin

The choke comes off fully in 6 - 8 mins or about 3 -5 miles.
This is a fuel related problem.
Too rich or too weak.
Has the mixture been analysed on a gas analyser?

Or a coil related problem
(does the coil get hot?)

Simple things to eliminate.